diff --git a/.gitmodules b/.gitmodules
index c7ae0834a..4961f226c 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -76,3 +76,6 @@
 [submodule "vendor/packages/Go.tmbundle"]
 	path = vendor/packages/Go.tmbundle
 	url = https://github.com/rsms/Go.tmbundle
+[submodule "vendor/bootstrap"]
+	path = vendor/bootstrap
+	url = https://github.com/twitter/bootstrap
diff --git a/.nakignore b/.nakignore
index 660678d6b..0a67982e7 100644
--- a/.nakignore
+++ b/.nakignore
@@ -1,3 +1,4 @@
 tags
 node_modules
 vendor/packages
+.git
diff --git a/docs/getting-started.md b/docs/getting-started.md
index d869e9506..75c4f21fd 100644
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@@ -6,12 +6,13 @@ about configuring, theming, and extending Atom.
 
 ## The Command Palette
 
-If there's one key-command you learn in Atom, it should be `meta-p`. You can
-always hit `meta-p` to bring up a list of commands that are relevant to the
-currently focused UI element. If there is a key binding for a given command, it
-is also displayed. This is a great way to explore the system and get to know the
-key commands interactively. If you'd like to add or change a binding for a
-command, refer to the [key bindings](#customizing-key-bindings) section to learn how.
+If there's one key-command you learn in Atom, it should be `meta-p` (`meta` is
+synonymous with the ⌘ key). You can always hit `meta-p` to bring up a list of
+commands that are relevant to the currently focused UI element. If there is a
+key binding for a given command, it is also displayed. This is a great way to
+explore the system and get to know the key commands interactively. If you'd like
+to add or change a binding for a command, refer to the [key
+bindings](#customizing-key-bindings) section to learn how.
 
 ![Command Palette](http://f.cl.ly/items/32041o3w471F3C0F0V2O/Screen%20Shot%202013-02-13%20at%207.27.41%20PM.png)
 
diff --git a/package.json b/package.json
index 80eca4b73..15d64f6ce 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,8 @@
     "spellchecker": "0.3.0",
     "pathwatcher": "0.3.0",
     "plist": "git://github.com/nathansobo/node-plist.git",
-    "space-pen": "git://github.com/nathansobo/space-pen.git"
+    "space-pen": "git://github.com/nathansobo/space-pen.git",
+    "less": "git://github.com/nathansobo/less.js.git"
   },
 
   "devDependencies" : {
diff --git a/script/compile-less.coffee b/script/compile-less.coffee
index 805d477d2..8e95d26d9 100644
--- a/script/compile-less.coffee
+++ b/script/compile-less.coffee
@@ -5,7 +5,7 @@ global.document =
 global.location =
   port: 80
 
-{less} = require '../vendor/less'
+less = require 'less'
 fs = require 'fs'
 
 inputFile = process.argv[2]
@@ -19,7 +19,19 @@ unless outputFile?.length > 0
   process.exit(1)
 
 contents = fs.readFileSync(inputFile)?.toString() ? ''
-(new less.Parser).parse contents, (e, tree) ->
-  console.error(e.stack or e) if e
-  process.exit(1) if e
-  fs.writeFileSync(outputFile, tree.toCSS())
+
+parser = new less.Parser
+  syncImport: true
+  paths: [fs.realpathSync("#{__dirname}/../static"), fs.realpathSync("#{__dirname}/../vendor")]
+  filename: inputFile
+
+logErrorAndExit = (e) ->
+  console.error("Error compiling less file '#{inputFile}':", e.message)
+  process.exit(1)
+
+parser.parse contents, (e, tree) ->
+  logErrorAndExit(e) if e
+  try
+    fs.writeFileSync(outputFile, tree.toCSS())
+  catch e
+    logErrorAndExit(e)
diff --git a/script/copy-files-to-bundle b/script/copy-files-to-bundle
index 586db807f..8aaec6ee2 100755
--- a/script/copy-files-to-bundle
+++ b/script/copy-files-to-bundle
@@ -10,6 +10,5 @@ RESOUCES_PATH="$BUILT_PRODUCTS_DIR/$UNLOCALIZED_RESOURCES_FOLDER_PATH"
 rsync --archive --recursive \
       --exclude="src/**.coffee" --exclude="src/**.cson" \
       --exclude="src/**.less" --exclude="static/**.less" \
-      --exclude="node_modules/less" \
       node_modules src static vendor spec benchmark themes dot-atom atom.sh \
       "${COMPILED_SOURCES_DIR}/" "$RESOUCES_PATH"
diff --git a/spec/app/image-view-spec.coffee b/spec/app/image-view-spec.coffee
index 896c70f54..d4dda8920 100644
--- a/spec/app/image-view-spec.coffee
+++ b/spec/app/image-view-spec.coffee
@@ -8,7 +8,7 @@ describe "ImageView", ->
     path = project.resolve('binary-file.png')
     view = new ImageView()
     view.attachToDom()
-    view.parent().height(100)
+    view.height(100)
 
   it "displays the image for a path", ->
     view.setModel(new ImageEditSession(path))
diff --git a/spec/app/select-list-spec.coffee b/spec/app/select-list-spec.coffee
index 0e3dec287..ea2b1e7da 100644
--- a/spec/app/select-list-spec.coffee
+++ b/spec/app/select-list-spec.coffee
@@ -113,7 +113,7 @@ describe "SelectList", ->
 
       miniEditor.trigger 'core:move-up'
       miniEditor.trigger 'core:move-up'
-      expect(list.scrollBottom()).toBe itemHeight * 3
+      expect(list.scrollTop()).toBe itemHeight
 
   describe "the core:confirm event", ->
     describe "when there is an item selected (because the list in not empty)", ->
diff --git a/spec/atom-reporter.coffee b/spec/atom-reporter.coffee
index c02035cc8..5636647ca 100644
--- a/spec/atom-reporter.coffee
+++ b/spec/atom-reporter.coffee
@@ -8,7 +8,7 @@ class AtomReporter extends View
     @div id: 'HTMLReporter', class: 'jasmine_reporter', =>
       @div outlet: 'specPopup', class: "spec-popup"
       @div outlet: "suites"
-      @ul outlet: "symbolSummary", class: 'symbolSummary'
+      @ul outlet: "symbolSummary", class: 'symbolSummary list-unstyled'
       @div outlet: "status", class: 'status', =>
         @div outlet: "time", class: 'time'
         @div outlet: "specCount", class: 'spec-count'
diff --git a/src/app/atom-package.coffee b/src/app/atom-package.coffee
index c7f5cfeb3..9013d461a 100644
--- a/src/app/atom-package.coffee
+++ b/src/app/atom-package.coffee
@@ -28,7 +28,7 @@ class AtomPackage extends Package
       else
         @requireMainModule()
     catch e
-      console.warn "Failed to load package named '#{@name}'", e.stack
+      console.warn "Failed to load package named '#{@name}'", e.stack ? e
     this
 
   activate: ({immediate}={}) ->
diff --git a/src/app/buffer-marker.coffee b/src/app/buffer-marker.coffee
index 6aa013e01..d232a11cd 100644
--- a/src/app/buffer-marker.coffee
+++ b/src/app/buffer-marker.coffee
@@ -107,14 +107,13 @@ class BufferMarker
 
   handleBufferChange: (bufferChange) ->
     @consolidateObserverNotifications true, =>
-      @setHeadPosition(@updatePosition(@headPosition, bufferChange, false), clip: false, bufferChanged: true)
-      @setTailPosition(@updatePosition(@tailPosition, bufferChange, true), clip: false, bufferChanged: true) if @tailPosition
+      @setHeadPosition(@updatePosition(@headPosition, bufferChange, true), clip: false, bufferChanged: true)
+      @setTailPosition(@updatePosition(@tailPosition, bufferChange, false), clip: false, bufferChanged: true) if @tailPosition
 
-  updatePosition: (position, bufferChange, isFirstPoint) ->
+  updatePosition: (position, bufferChange, isHead) ->
     { oldRange, newRange } = bufferChange
 
-    return position if oldRange.containsPoint(position, exclusive: true)
-    return position if isFirstPoint and oldRange.start.isEqual(position)
+    return position if not isHead and oldRange.start.isEqual(position)
     return position if position.isLessThan(oldRange.end)
 
     newRow = newRange.end.row
diff --git a/src/app/config.coffee b/src/app/config.coffee
index 455901565..ac44ca272 100644
--- a/src/app/config.coffee
+++ b/src/app/config.coffee
@@ -21,6 +21,7 @@ class Config
   themeDirPaths: [userThemesDirPath, bundledThemesDirPath, vendoredThemesDirPath]
   packageDirPaths: [userPackagesDirPath, vendoredPackagesDirPath, bundledPackagesDirPath]
   userPackagesDirPath: userPackagesDirPath
+  lessSearchPaths: [fsUtils.join(resourcePath, 'static'), fsUtils.join(resourcePath, 'vendor')]
   defaultSettings: null
   settings: null
   configFileHasErrors: null
diff --git a/src/app/cursor-view.coffee b/src/app/cursor-view.coffee
index 3cef15ba2..1bfb5d204 100644
--- a/src/app/cursor-view.coffee
+++ b/src/app/cursor-view.coffee
@@ -7,7 +7,7 @@ module.exports =
 class CursorView extends View
   # Internal:
   @content: ->
-    @pre class: 'cursor idle', => @raw ' '
+    @div class: 'cursor idle', => @raw ' '
 
   blinkPeriod: 800
   editor: null
diff --git a/src/app/editor.coffee b/src/app/editor.coffee
index 5282bb998..75c441f48 100644
--- a/src/app/editor.coffee
+++ b/src/app/editor.coffee
@@ -730,10 +730,6 @@ class Editor extends View
     @verticalScrollbar.on 'scroll', =>
       @scrollTop(@verticalScrollbar.scrollTop(), adjustVerticalScrollbar: false)
 
-    unless @mini
-      @gutter.widthChanged = (newWidth) =>
-        @scrollView.css('left', newWidth + 'px')
-
     @scrollView.on 'scroll', =>
       if @scrollView.scrollLeft() == 0
         @gutter.removeClass('drop-shadow')
@@ -766,7 +762,6 @@ class Editor extends View
     return if @attached
     @attached = true
     @calculateDimensions()
-    @hiddenInput.width(@charWidth)
     @setSoftWrapColumn() if @activeEditSession.getSoftWrap()
     @subscribe $(window), "resize.editor-#{@id}", => @requestDisplayUpdate()
     @focus() if @isFocused
@@ -1108,7 +1103,7 @@ class Editor extends View
 
   # Internal:
   calculateDimensions: ->
-    fragment = $('<pre class="line" style="position: absolute; visibility: hidden;"><span>x</span></div>')
+    fragment = $('<div class="line" style="position: absolute; visibility: hidden;"><span>x</span></div>')
     @renderedLines.append(fragment)
 
     lineRect = fragment[0].getBoundingClientRect()
@@ -1116,7 +1111,6 @@ class Editor extends View
     @lineHeight = lineRect.height
     @charWidth = charRect.width
     @charHeight = charRect.height
-    @height(@lineHeight) if @mini
     fragment.remove()
 
   updateLayerDimensions: ->
@@ -1446,7 +1440,7 @@ class Editor extends View
 
     attributePairs = []
     attributePairs.push "#{attributeName}=\"#{value}\"" for attributeName, value of lineAttributes
-    line.push("<pre #{attributePairs.join(' ')}>")
+    line.push("<div #{attributePairs.join(' ')}>")
 
     invisibles = @invisibles if @showInvisibles
 
@@ -1475,7 +1469,7 @@ class Editor extends View
 
     line.push("<span class='fold-marker'/>") if fold
 
-    line.push('</pre>')
+    line.push('</div>')
     line.join('')
 
   lineElementForScreenRow: (screenRow) ->
diff --git a/src/app/gutter.coffee b/src/app/gutter.coffee
index aabf890c2..df2dc0dc4 100644
--- a/src/app/gutter.coffee
+++ b/src/app/gutter.coffee
@@ -16,7 +16,6 @@ class Gutter extends View
 
   firstScreenRow: Infinity
   lastScreenRow: -1
-  highestNumberWidth: null
 
   # Internal:
   afterAttach: (onDom) ->
diff --git a/src/app/window.coffee b/src/app/window.coffee
index 53c2c95b6..a92306629 100644
--- a/src/app/window.coffee
+++ b/src/app/window.coffee
@@ -2,7 +2,7 @@ fs = require 'fs'
 fsUtils = require 'fs-utils'
 $ = require 'jquery'
 _ = require 'underscore'
-{less} = require 'less'
+less = require 'less'
 require 'jquery-extensions'
 require 'underscore-extensions'
 require 'space-pen-extensions'
@@ -25,12 +25,7 @@ window.setUpEnvironment = ->
   $(document).on 'keydown', keymap.handleKeyEvent
   keymap.bindDefaultKeys()
 
-  requireStylesheet 'reset'
   requireStylesheet 'atom'
-  requireStylesheet 'overlay'
-  requireStylesheet 'popover-list'
-  requireStylesheet 'notification'
-  requireStylesheet 'markdown'
 
   if nativeStylesheetPath = fsUtils.resolveOnLoadPath(process.platform, ['css', 'less'])
     requireStylesheet(nativeStylesheetPath)
@@ -140,13 +135,28 @@ window.requireStylesheet = (path) ->
     throw new Error("Could not find a file at path '#{path}'")
 
 window.loadStylesheet = (path) ->
-  content = fsUtils.read(path)
   if fsUtils.extension(path) == '.less'
-    (new less.Parser).parse content, (e, tree) ->
-      throw new Error(e.message, path, e.line) if e
-      content = tree.toCSS()
+    loadLessStylesheet(path)
+  else
+    fsUtils.read(path)
 
-  content
+window.loadLessStylesheet = (path) ->
+  parser = new less.Parser
+    syncImport: true
+    paths: config.lessSearchPaths
+    filename: path
+  try
+    content = null
+    parser.parse fsUtils.read(path), (e, tree) ->
+      throw e if e?
+      content = tree.toCSS()
+    content
+  catch e
+    console.error """
+      Error compiling less stylesheet: #{path}
+      Line number: #{e.line}
+      #{e.message}
+    """
 
 window.removeStylesheet = (path) ->
   unless fullPath = window.resolveStylesheet(path)
diff --git a/src/packages/autocomplete/stylesheets/autocomplete.less b/src/packages/autocomplete/stylesheets/autocomplete.less
index 1c7a332e7..eb78828b6 100644
--- a/src/packages/autocomplete/stylesheets/autocomplete.less
+++ b/src/packages/autocomplete/stylesheets/autocomplete.less
@@ -4,6 +4,7 @@
 }
 
 .autocomplete ol {
+  box-sizing: content-box;
   position: relative;
   overflow-y: scroll;
   max-height: 200px;
diff --git a/src/packages/command-palette/lib/command-palette-view.coffee b/src/packages/command-palette/lib/command-palette-view.coffee
index 34988e751..6194abddf 100644
--- a/src/packages/command-palette/lib/command-palette-view.coffee
+++ b/src/packages/command-palette/lib/command-palette-view.coffee
@@ -49,7 +49,7 @@ class CommandPaletteView extends SelectList
     keyBindings = @keyBindings
     $$ ->
       @li class: 'event', 'data-event-name': eventName, =>
-        @span eventDescription, class: 'label', title: eventName
+        @span eventDescription, title: eventName
         @div class: 'right', =>
           for binding in keyBindings[eventName] ? []
             @kbd binding, class: 'key-binding'
diff --git a/src/packages/command-palette/spec/command-palette-spec.coffee b/src/packages/command-palette/spec/command-palette-spec.coffee
index a0de19c61..6d294185a 100644
--- a/src/packages/command-palette/spec/command-palette-spec.coffee
+++ b/src/packages/command-palette/spec/command-palette-spec.coffee
@@ -24,8 +24,8 @@ describe "CommandPalette", ->
         eventLi = palette.list.children("[data-event-name='#{eventName}']")
         if description
           expect(eventLi).toExist()
-          expect(eventLi.find('.label')).toHaveText(description)
-          expect(eventLi.find('.label').attr('title')).toBe(eventName)
+          expect(eventLi.find('span')).toHaveText(description)
+          expect(eventLi.find('span').attr('title')).toBe(eventName)
           for binding in keyBindings[eventName] ? []
             expect(eventLi.find(".key-binding:contains(#{binding})")).toExist()
         else
@@ -40,8 +40,8 @@ describe "CommandPalette", ->
         description = editorEvents[eventName] unless description
         if description
           expect(eventLi).toExist()
-          expect(eventLi.find('.label')).toHaveText(description)
-          expect(eventLi.find('.label').attr('title')).toBe(eventName)
+          expect(eventLi.find('span')).toHaveText(description)
+          expect(eventLi.find('span').attr('title')).toBe(eventName)
         else
           expect(eventLi).not.toExist()
 
@@ -92,8 +92,8 @@ describe "CommandPalette", ->
         eventLi = palette.list.children("[data-event-name='#{eventName}']")
         if description
           expect(eventLi).toExist()
-          expect(eventLi.find('.label')).toHaveText(description)
-          expect(eventLi.find('.label').attr('title')).toBe(eventName)
+          expect(eventLi.find('span')).toHaveText(description)
+          expect(eventLi.find('span').attr('title')).toBe(eventName)
           for binding in keyBindings[eventName] ? []
             expect(eventLi.find(".key-binding:contains(#{binding})")).toExist()
         else
diff --git a/src/packages/command-panel/lib/command-panel-view.coffee b/src/packages/command-panel/lib/command-panel-view.coffee
index a5ef8b681..38791ddab 100644
--- a/src/packages/command-panel/lib/command-panel-view.coffee
+++ b/src/packages/command-panel/lib/command-panel-view.coffee
@@ -13,9 +13,8 @@ class CommandPanelView extends View
     @div class: 'command-panel tool-panel', =>
       @div class: 'loading is-loading', outlet: 'loadingMessage', 'Searching...'
       @div class: 'header', outlet: 'previewHeader', =>
-        @ul outlet: 'expandCollapse', class: 'expand-collapse', =>
-          @li class: 'expand', 'Expand All'
-          @li class: 'collapse', 'Collapse All'
+        @button outlet: 'collapseAll', class: 'btn btn-mini pull-right', 'Collapse All'
+        @button outlet: 'expandAll', class: 'btn btn-mini pull-right', 'Expand All'
         @span outlet: 'previewCount', class: 'preview-count'
 
       @subview 'previewList', new PreviewList(rootView)
@@ -47,8 +46,8 @@ class CommandPanelView extends View
     @subscribeToCommand rootView, 'command-panel:repeat-relative-address-in-reverse', => @repeatRelativeAddress(reverse: true)
     @subscribeToCommand rootView, 'command-panel:set-selection-as-regex-address', => @setSelectionAsLastRelativeAddress()
 
-    @on 'click', '.expand', @onExpandAll
-    @on 'click', '.collapse', @onCollapseAll
+    @expandAll.on 'click', @onExpandAll
+    @collapseAll.on 'click', @onCollapseAll
 
     @previewList.hide()
     @previewHeader.hide()
diff --git a/src/packages/command-panel/spec/command-panel-spec.coffee b/src/packages/command-panel/spec/command-panel-spec.coffee
index 782399da3..be448d0bb 100644
--- a/src/packages/command-panel/spec/command-panel-spec.coffee
+++ b/src/packages/command-panel/spec/command-panel-spec.coffee
@@ -139,7 +139,8 @@ describe "CommandPanel", ->
             expect(commandPanel.previewList).toBeVisible()
 
           it  "shows the expand and collapse all buttons", ->
-            expect(commandPanel.find('.expand-collapse')).toBeVisible()
+            expect(commandPanel.collapseAll).toBeVisible()
+            expect(commandPanel.expandAll).toBeVisible()
 
           describe "when the preview list is focused", ->
             it "hides the command panel", ->
diff --git a/src/packages/command-panel/stylesheets/command-panel.less b/src/packages/command-panel/stylesheets/command-panel.less
index 15a133ec7..1aa0928bb 100644
--- a/src/packages/command-panel/stylesheets/command-panel.less
+++ b/src/packages/command-panel/stylesheets/command-panel.less
@@ -92,6 +92,11 @@
         padding: 1px;
       }
     }
+
+    .matches {
+      list-style-type: none;
+      margin: 0;
+    }
   }
 
   .header:after {
@@ -105,6 +110,7 @@
   .expand-collapse {
     float: right;
     -webkit-user-select: none;
+    margin: 0;
 
     li {
       display: inline-block;
@@ -113,6 +119,7 @@
       margin-left: 5px;
       padding: 5px 10px;
       border-radius: 3px;
+      line-height: normal;
     }
   }
 
@@ -124,9 +131,15 @@
       -webkit-flex: 1;
     }
   }
-}
 
-.error-messages {
-  padding: 5px 1em;
-  color: white;
+  .error-messages {
+    list-style-type: none;
+    margin: 0;
+    padding: 5px 1em;
+    color: white;
+  }
+
+  .btn {
+    margin-left: 5px;
+  }
 }
diff --git a/src/packages/fuzzy-finder/lib/fuzzy-finder-view.coffee b/src/packages/fuzzy-finder/lib/fuzzy-finder-view.coffee
index 8bdfc5521..0080f7bbb 100644
--- a/src/packages/fuzzy-finder/lib/fuzzy-finder-view.coffee
+++ b/src/packages/fuzzy-finder/lib/fuzzy-finder-view.coffee
@@ -59,7 +59,7 @@ class FuzzyFinderView extends SelectList
         else
           typeClass = 'text-name'
 
-        @span fsUtils.base(path), class: "file label #{typeClass}"
+        @span fsUtils.base(path), class: "file #{typeClass}"
         if folder = project.relativize(fsUtils.directory(path))
           @span " - #{folder}/", class: 'directory'
 
diff --git a/src/packages/symbols-view/lib/symbols-view.coffee b/src/packages/symbols-view/lib/symbols-view.coffee
index a6f617139..b5ff72e57 100644
--- a/src/packages/symbols-view/lib/symbols-view.coffee
+++ b/src/packages/symbols-view/lib/symbols-view.coffee
@@ -26,7 +26,7 @@ class SymbolsView extends SelectList
   itemForElement: ({position, name, file}) ->
     $$ ->
       @li =>
-        @div name, class: 'label'
+        @span name
         if position
           text = "Line #{position.row + 1}"
         else
diff --git a/src/packages/symbols-view/spec/symbols-view-spec.coffee b/src/packages/symbols-view/spec/symbols-view-spec.coffee
index 4762ba421..8c43ecf8b 100644
--- a/src/packages/symbols-view/spec/symbols-view-spec.coffee
+++ b/src/packages/symbols-view/spec/symbols-view-spec.coffee
@@ -30,9 +30,9 @@ describe "SymbolsView", ->
         expect(symbolsView.find('.loading')).toBeEmpty()
         expect(rootView.find('.symbols-view')).toExist()
         expect(symbolsView.list.children('li').length).toBe 2
-        expect(symbolsView.list.children('li:first').find('.label')).toHaveText 'quicksort'
+        expect(symbolsView.list.children('li:first').find('span')).toHaveText 'quicksort'
         expect(symbolsView.list.children('li:first').find('.function-details')).toHaveText 'Line 1'
-        expect(symbolsView.list.children('li:last').find('.label')).toHaveText 'quicksort.sort'
+        expect(symbolsView.list.children('li:last').find('span')).toHaveText 'quicksort.sort'
         expect(symbolsView.list.children('li:last').find('.function-details')).toHaveText 'Line 2'
         expect(symbolsView).not.toHaveClass "error"
         expect(symbolsView.error).not.toBeVisible()
@@ -175,7 +175,7 @@ describe "SymbolsView", ->
         editor.trigger 'symbols-view:go-to-declaration'
         symbolsView = rootView.find('.symbols-view').view()
         expect(symbolsView.list.children('li').length).toBe 1
-        expect(symbolsView.list.children('li:first').find('.label')).toHaveText 'tagged.js'
+        expect(symbolsView.list.children('li:first').find('span')).toHaveText 'tagged.js'
 
   describe "project symbols", ->
     it "displays all tags", ->
@@ -192,9 +192,9 @@ describe "SymbolsView", ->
         expect(symbolsView.find('.loading')).toBeEmpty()
         expect(rootView.find('.symbols-view')).toExist()
         expect(symbolsView.list.children('li').length).toBe 4
-        expect(symbolsView.list.children('li:first').find('.label')).toHaveText 'callMeMaybe'
+        expect(symbolsView.list.children('li:first').find('span')).toHaveText 'callMeMaybe'
         expect(symbolsView.list.children('li:first').find('.function-details')).toHaveText 'tagged.js'
-        expect(symbolsView.list.children('li:last').find('.label')).toHaveText 'thisIsCrazy'
+        expect(symbolsView.list.children('li:last').find('span')).toHaveText 'thisIsCrazy'
         expect(symbolsView.list.children('li:last').find('.function-details')).toHaveText 'tagged.js'
         expect(symbolsView).not.toHaveClass "error"
         expect(symbolsView.error).not.toBeVisible()
diff --git a/src/packages/tabs/lib/tab-bar-view.coffee b/src/packages/tabs/lib/tab-bar-view.coffee
index 9bd4227c4..6b524c2a7 100644
--- a/src/packages/tabs/lib/tab-bar-view.coffee
+++ b/src/packages/tabs/lib/tab-bar-view.coffee
@@ -6,7 +6,7 @@ TabView = require './tab-view'
 module.exports =
 class TabBarView extends View
   @content: ->
-    @ul tabindex: -1, class: "tabs sortable-list"
+    @ul tabindex: -1, class: "list-inline tabs"
 
   initialize: (@pane) ->
     @on 'dragstart', '.sortable', @onDragStart
diff --git a/src/packages/tabs/lib/tab-view.coffee b/src/packages/tabs/lib/tab-view.coffee
index 9c5faab90..ed817af58 100644
--- a/src/packages/tabs/lib/tab-view.coffee
+++ b/src/packages/tabs/lib/tab-view.coffee
@@ -6,8 +6,8 @@ module.exports =
 class TabView extends View
   @content: ->
     @li class: 'tab sortable', =>
-      @span class: 'title', outlet: 'title'
-      @span class: 'close-icon'
+      @div class: 'title', outlet: 'title'
+      @div class: 'close-icon'
 
   initialize: (@item, @pane) ->
     @item.on? 'title-changed', => @updateTitle()
diff --git a/src/packages/tabs/stylesheets/tabs.less b/src/packages/tabs/stylesheets/tabs.less
index 120503c5d..efa2119d9 100644
--- a/src/packages/tabs/stylesheets/tabs.less
+++ b/src/packages/tabs/stylesheets/tabs.less
@@ -1,87 +1,59 @@
+@import "bootstrap/less/variables.less";
+@import "octicon-mixins.less";
+
+@close-icon-size: 11px;
+
 .tabs {
-  font: caption;
   display: -webkit-flex;
-  -webkit-box-align: center;
-}
-
-.tab {
   -webkit-user-select: none;
-  -webkit-user-drag: element;
-  cursor: default;
-  -webkit-flex: 1;
-  width: 175px;
-  max-width: 175px;
-  min-width: 40px;
-  box-sizing: border-box;
-  text-shadow: -1px -1px 0 #000;
-  font-size: 11px;
-  padding: 5px 10px;
-  position: relative;
-}
+  margin: 0;
 
-.tab.active {
-  -webkit-flex: 2;
-}
+  .tab {
+    line-height: 30px;
+    font-size: 11px;
+    position: relative;
+    padding-left: 10px;
+    padding-right: 10px + @close-icon-size + 2px;
+    -webkit-user-drag: element;
+    -webkit-flex: 1;
+    max-width: 175px;
+    min-width: 40px;
 
-.tab .title {
-  display: block;
-  overflow: hidden;
-  white-space: nowrap;
-  text-overflow: ellipsis;
-  padding: 3px 10px 3px 0;
-}
+    &.active {
+      -webkit-flex: 2;
+    }
 
-.tab .close-icon {
-  font-family: 'Octicons Regular';
-  font-size: 12px;
-  width: 12px;
-  height: 12px;
-  cursor: pointer;
-  position: absolute;
-  color: rgba(255, 255, 255, 0.5);
-  right: 8px;
-  top: 5px;
-  -webkit-font-smoothing: antialiased;
-}
+    .title {
+      overflow: hidden;
+      white-space: nowrap;
+      text-overflow: ellipsis;
+    }
 
-.tab .close-icon:before {
-  content: "\f081";
-}
+    .close-icon {
+      .mini-icon(x, @close-icon-size);
+      position: absolute;
+      top: 0px;
+      right: 10px;
+      cursor: pointer;
+    }
 
-.tab .close-icon:hover {
-  color: #fff;
-}
+    &.modified:hover .close-icon {
+      color: #66a6ff;
+    }
 
-.tab.modified .close-icon {
-  top: 11px;
-  width: 5px;
-  height: 5px;
-  right: 9px;
-  border: 2px solid #66a6ff;
-  border-radius: 12px;
-}
-
-.tab.modified .close-icon:before {
-  content: "";
-}
-
-.tab.modified:hover .close-icon {
-  border: none;
-  width: 12px;
-  height: 12px;
-  right: 8px;
-  top: 5px;
-}
-
-.tab.modified:hover .close-icon:before {
-  content: "\f081";
-  color: #66a6ff;
+    &.modified:not(:hover) .close-icon {
+      &:before { content: "" }
+      top: 11px;
+      right: 11px;
+      width: 8px;
+      height: 8px;
+      border: 2px solid #66a6ff;
+      border-radius: 12px;
+    }
+  }
 }
 
 /* Drag and Drop */
-.tab.is-dragging {
-
-}
 
 .tab.is-drop-target:before, .tab.drop-target-is-after:after {
   content: "";
diff --git a/src/packages/tree-view/lib/directory-view.coffee b/src/packages/tree-view/lib/directory-view.coffee
index 8d58bcfb2..e1ebb798f 100644
--- a/src/packages/tree-view/lib/directory-view.coffee
+++ b/src/packages/tree-view/lib/directory-view.coffee
@@ -8,10 +8,10 @@ module.exports =
 class DirectoryView extends View
   @content: ({directory, isExpanded} = {}) ->
     @li class: 'directory entry', =>
+      @span class: 'highlight'
       @div outlet: 'header', class: 'header', =>
         @span class: 'disclosure-arrow', outlet: 'disclosureArrow'
         @span directory.getBaseName(), class: 'name', outlet: 'directoryName'
-      @span class: 'highlight'
 
   directory: null
   entries: null
@@ -60,7 +60,7 @@ class DirectoryView extends View
   buildEntries: ->
     @unwatchDescendantEntries()
     @entries?.remove()
-    @entries = $$ -> @ol class: 'entries'
+    @entries = $$ -> @ol class: 'entries list-unstyled'
     for entry in @directory.getEntries()
       continue if @isPathIgnored(entry.path)
       if entry instanceof Directory
diff --git a/src/packages/tree-view/lib/file-view.coffee b/src/packages/tree-view/lib/file-view.coffee
index 1aea8286b..fb1790fa4 100644
--- a/src/packages/tree-view/lib/file-view.coffee
+++ b/src/packages/tree-view/lib/file-view.coffee
@@ -8,8 +8,8 @@ class FileView extends View
 
   @content: ({file} = {}) ->
     @li class: 'file entry', =>
-      @span file.getBaseName(), class: 'name', outlet: 'fileName'
       @span class: 'highlight'
+      @span file.getBaseName(), class: 'name', outlet: 'fileName'
 
   file: null
 
diff --git a/src/packages/tree-view/lib/tree-view.coffee b/src/packages/tree-view/lib/tree-view.coffee
index 6e0aa25b2..535f87e88 100644
--- a/src/packages/tree-view/lib/tree-view.coffee
+++ b/src/packages/tree-view/lib/tree-view.coffee
@@ -11,9 +11,10 @@ _ = require 'underscore'
 module.exports =
 class TreeView extends ScrollView
   @content: (rootView) ->
-    @div class: 'tree-view-wrapper', =>
-      @ol class: 'tree-view tool-panel', tabindex: -1, outlet: 'treeViewList'
-      @div class: 'tree-view-resizer', outlet: 'resizer'
+    @div class: 'tree-view-resizer', =>
+      @div class: 'tree-view-scroller', outlet: 'scroller', =>
+        @ol class: 'list-unstyled tree-view tool-panel', tabindex: -1, outlet: 'list'
+      @div class: 'tree-view-resize-handle', outlet: 'resizeHandle'
 
   root: null
   focusAfterAttach: false
@@ -23,7 +24,7 @@ class TreeView extends ScrollView
   initialize: (state) ->
     super
     @on 'click', '.entry', (e) => @entryClicked(e)
-    @on 'mousedown', '.tree-view-resizer', (e) => @resizeStarted(e)
+    @on 'mousedown', '.tree-view-resize-handle', (e) => @resizeStarted(e)
     @command 'core:move-up', => @moveUp()
     @command 'core:move-down', => @moveDown()
     @command 'core:close', => @detach(); false
@@ -56,7 +57,6 @@ class TreeView extends ScrollView
   afterAttach: (onDom) ->
     @focus() if @focusAfterAttach
     @scrollTop(@scrollTopAfterAttach) if @scrollTopAfterAttach > 0
-    @find('.selected > .highlight').width(@treeViewList[0].scrollWidth)
 
   serialize: ->
     directoryExpansionStates: @root?.serializeEntryExpansionStates()
@@ -89,10 +89,10 @@ class TreeView extends ScrollView
     rootView.focus()
 
   focus: ->
-    @treeViewList.focus()
+    @list.focus()
 
   hasFocus: ->
-    @treeViewList.is(':focus')
+    @list.is(':focus')
 
   entryClicked: (e) ->
     entry = $(e.currentTarget).view()
@@ -111,12 +111,10 @@ class TreeView extends ScrollView
   resizeStarted: (e) =>
     $(document.body).on('mousemove', @resizeTreeView)
     $(document.body).on('mouseup', @resizeStopped)
-    @css(overflow: 'hidden')
 
   resizeStopped: (e) =>
     $(document.body).off('mousemove', @resizeTreeView)
     $(document.body).off('mouseup', @resizeStopped)
-    @css(overflow: 'auto')
 
   resizeTreeView: (e) =>
     @css(width: e.pageX)
@@ -126,7 +124,7 @@ class TreeView extends ScrollView
 
     if rootDirectory = project.getRootDirectory()
       @root = new DirectoryView(directory: rootDirectory, isExpanded: true, project: project)
-      @treeViewList.append(@root)
+      @list.append(@root)
     else
       @root = null
 
@@ -162,7 +160,7 @@ class TreeView extends ScrollView
       else
         bestMatchEntry
 
-    @treeViewList.find(".entry").toArray().reduce(fn, @root)
+    @list.find(".entry").toArray().reduce(fn, @root)
 
   selectEntryForPath: (path) ->
     @selectEntry(@entryForPath(path))
@@ -189,7 +187,7 @@ class TreeView extends ScrollView
       else
         @selectEntry(selectedEntry.parents('.directory').first())
     else
-      @selectEntry(@treeViewList.find('.entry').last())
+      @selectEntry(@list.find('.entry').last())
 
     @scrollToEntry(@selectedEntry())
 
@@ -298,47 +296,43 @@ class TreeView extends ScrollView
     rootView.append(dialog)
 
   selectedEntry: ->
-    @treeViewList.find('.selected')?.view()
+    @list.find('.selected')?.view()
 
   selectEntry: (entry) ->
     return false unless entry.get(0)
     entry = entry.view() unless entry instanceof View
     @selectedPath = entry.getPath()
     @deselect()
-    entry.children('.highlight').width(@treeViewList[0].scrollWidth)
     entry.addClass('selected')
 
   deselect: ->
-    @treeViewList.find('.selected').removeClass('selected').children('.highlight').width('')
+    @list.find('.selected').removeClass('selected')
 
   scrollTop: (top) ->
-    if top
-      @treeViewList.scrollTop(top)
+    if top?
+      @scroller.scrollTop(top)
     else
-      @treeViewList.scrollTop()
+      @scroller.scrollTop()
 
   scrollBottom: (bottom) ->
-    if bottom
-      @treeViewList.scrollBottom(bottom)
+    if bottom?
+      @scroller.scrollBottom(bottom)
     else
-      @treeViewList.scrollBottom()
+      @scroller.scrollBottom()
 
   scrollToEntry: (entry) ->
     displayElement = if entry instanceof DirectoryView then entry.header else entry
-    top = @scrollTop() + displayElement.position().top
+    top = displayElement.position().top
     bottom = top + displayElement.outerHeight()
     if bottom > @scrollBottom()
-      @treeViewList.scrollBottom(bottom)
+      @scrollBottom(bottom)
     if top < @scrollTop()
-      @treeViewList.scrollTop(top)
+      @scrollTop(top)
 
   scrollToBottom: ->
-    super()
-
     @selectEntry(@root.find('.entry:last')) if @root
     @scrollToEntry(@root.find('.entry:last')) if @root
 
   scrollToTop: ->
-    super()
     @selectEntry(@root) if @root
-    @treeViewList.scrollTop(0)
+    @scrollTop(0)
diff --git a/src/packages/tree-view/spec/tree-view-spec.coffee b/src/packages/tree-view/spec/tree-view-spec.coffee
index a79b4f116..53cbca5c0 100644
--- a/src/packages/tree-view/spec/tree-view-spec.coffee
+++ b/src/packages/tree-view/spec/tree-view-spec.coffee
@@ -101,11 +101,11 @@ describe "TreeView", ->
     it "restores the focus state of the tree view", ->
       rootView.attachToDom()
       treeView.focus()
-      expect(treeView.find(".tree-view")).toMatchSelector ':focus'
+      expect(treeView.list).toMatchSelector ':focus'
       atom.deactivatePackage("tree-view")
       atom.activatePackage("tree-view")
       treeView = rootView.find(".tree-view").view()
-      expect(treeView.find(".tree-view")).toMatchSelector ':focus'
+      expect(treeView.list).toMatchSelector ':focus'
 
     it "restores the scroll top when toggled", ->
       rootView.height(5)
@@ -142,14 +142,14 @@ describe "TreeView", ->
           rootView.focus()
           rootView.trigger 'tree-view:toggle'
           expect(treeView).toBeVisible()
-          expect(treeView.find(".tree-view")).toMatchSelector(':focus')
+          expect(treeView.list).toMatchSelector(':focus')
 
     describe "when the tree view is hidden", ->
       it "shows and focuses the tree view", ->
         treeView.detach()
         rootView.trigger 'tree-view:toggle'
         expect(treeView.hasParent()).toBeTruthy()
-        expect(treeView.find(".tree-view")).toMatchSelector(':focus')
+        expect(treeView.list).toMatchSelector(':focus')
 
   describe "when tree-view:reveal-current-file is triggered on the root view", ->
     beforeEach ->
@@ -184,10 +184,10 @@ describe "TreeView", ->
       rootView.open() # When we trigger 'tool-panel:unfocus' below, we want an editor to become focused
       rootView.attachToDom()
       treeView.focus()
-      expect(treeView.find(".tree-view")).toMatchSelector(':focus')
+      expect(treeView.list).toMatchSelector(':focus')
       treeView.trigger 'tool-panel:unfocus'
       expect(treeView).toBeVisible()
-      expect(treeView.find(".tree-view")).not.toMatchSelector(':focus')
+      expect(treeView.list).not.toMatchSelector(':focus')
       expect(rootView.getActiveView().isFocused).toBeTruthy()
 
   describe "when core:close is triggered on the tree view", ->
@@ -428,7 +428,7 @@ describe "TreeView", ->
         treeView.height(100)
         treeView.attachToDom()
         $(element).view().expand() for element in treeView.find('.directory')
-        expect(treeView.find(".tree-view").prop('scrollHeight')).toBeGreaterThan treeView.find(".tree-view").outerHeight()
+        expect(treeView.list.outerHeight()).toBeGreaterThan treeView.scroller.outerHeight()
 
         expect(treeView.scrollTop()).toBe 0
 
@@ -452,11 +452,11 @@ describe "TreeView", ->
         treeView.height(100)
         treeView.attachToDom()
         $(element).view().expand() for element in treeView.find('.directory')
-        expect(treeView.find(".tree-view").prop('scrollHeight')).toBeGreaterThan treeView.find(".tree-view").outerHeight()
+        expect(treeView.list.outerHeight()).toBeGreaterThan treeView.scroller.outerHeight()
 
         expect(treeView.scrollTop()).toBe 0
         treeView.trigger 'core:move-to-bottom'
-        expect(treeView.scrollBottom()).toBe treeView.find(".tree-view").prop('scrollHeight')
+        expect(treeView.scrollBottom()).toBe treeView.root.outerHeight()
 
       it "selects the last entry", ->
         expect(treeView.root).toHaveClass 'selected'
@@ -468,7 +468,7 @@ describe "TreeView", ->
         treeView.height(5)
         treeView.attachToDom()
         $(element).view().expand() for element in treeView.find('.directory')
-        expect(treeView.find(".tree-view").prop('scrollHeight')).toBeGreaterThan treeView.find(".tree-view").outerHeight()
+        expect(treeView.list.outerHeight()).toBeGreaterThan treeView.scroller.outerHeight()
 
         expect(treeView.scrollTop()).toBe 0
         treeView.scrollToBottom()
@@ -483,7 +483,7 @@ describe "TreeView", ->
         treeView.height(5)
         treeView.attachToDom()
         $(element).view().expand() for element in treeView.find('.directory')
-        expect(treeView.find(".tree-view").prop('scrollHeight')).toBeGreaterThan treeView.find(".tree-view").outerHeight()
+        expect(treeView.list.outerHeight()).toBeGreaterThan treeView.scroller.outerHeight()
 
         expect(treeView.scrollTop()).toBe 0
         treeView.trigger 'core:page-down'
@@ -494,14 +494,16 @@ describe "TreeView", ->
         treeView.height(100)
         treeView.attachToDom()
         $(element).view().expand() for element in treeView.find('.directory')
-        expect(treeView.find(".tree-view").prop('scrollHeight')).toBeGreaterThan treeView.find(".tree-view").outerHeight()
+        expect(treeView.list.outerHeight()).toBeGreaterThan treeView.scroller.outerHeight()
 
         treeView.moveDown()
         expect(treeView.scrollTop()).toBe 0
 
         entryCount = treeView.find(".entry").length
+        entryHeight = treeView.find('.file').height()
+
         _.times entryCount, -> treeView.moveDown()
-        expect(treeView.scrollBottom()).toBe treeView.find(".tree-view").prop('scrollHeight')
+        expect(treeView.scrollBottom()).toBeGreaterThan (entryCount * entryHeight) - 1
 
         _.times entryCount, -> treeView.moveUp()
         expect(treeView.scrollTop()).toBe 0
diff --git a/src/packages/tree-view/stylesheets/tree-view.less b/src/packages/tree-view/stylesheets/tree-view.less
index d082dead4..4e02304b3 100644
--- a/src/packages/tree-view/stylesheets/tree-view.less
+++ b/src/packages/tree-view/stylesheets/tree-view.less
@@ -1,153 +1,16 @@
-.tree-view .entries {
-  margin-left: 12px;
-}
+@import "bootstrap/less/variables.less";
+@import "octicon-mixins.less";
 
-.tree-view .entries .file .name {
-  margin-left: 20px;
-}
-
-.tree-view .file .name,
-.tree-view .directory .header {
-  padding-top: 4px;
-  padding-bottom: 4px;
-  padding-right: 10px;
-}
-
-.tree-view .directory .header {
-  padding-left: 5px;
-}
-
-.tree-view-dialog {
-  padding: 5px;
-}
-
-.tree-view-dialog .prompt {
-  padding-bottom: 3px;
-  font-size: 12px;
-  line-height: 16px;
-}
-
-.tree-view-dialog .prompt span {
-  position: relative;
-  top: -1px;
-}
-
-.tree-view-dialog .prompt:before {
-  font-family: 'Octicons Regular';
-  font-size: 16px;
-  width: 16px;
-  height: 16px;
-  margin-right: 3px;
-  -webkit-font-smoothing: antialiased;
-}
-
-.tree-view-dialog .prompt.add-file:before {
-  content: "\f086";
-}
-
-.tree-view-dialog .prompt.add-directory:before {
-  content: "\f095";
-}
-
-.tree-view-dialog .prompt.move:before {
-  content: "\f03e";
-}
-
-.tree-view .directory .header .name,
-.tree-view .file .name {
-  position: relative;
-  padding-left: 21px;
-}
-
-.tree-view .directory .header .name:before,
-.tree-view .file .name:before {
-  font-family: 'Octicons Regular';
-  font-size: 16px;
-  width: 16px;
-  height: 16px;
-  margin-right: 5px;
-  -webkit-font-smoothing: antialiased;
-  position: absolute;
-  left: 0;
-}
-
-.tree-view .disclosure-arrow:before {
-  font-family: 'Octicons Regular';
-  font-size: 12px;
-  width: 12px;
-  height: 12px;
-  line-height: 16px;
-  margin-right: 3px;
-  -webkit-font-smoothing: antialiased;
-}
-
-.tree-view .directory .header .directory-icon:before {
-  content: "\f016";
-  top: -5px;
-}
-
-.tree-view .directory .header .repository-icon:before {
-  content: "\f001";
-  top: -4px;
-}
-
-.tree-view .directory .header .submodule-icon:before {
-  content: "\f017";
-  top: -5px;
-}
-
-.tree-view .file .text-icon:before {
-  content: "\f011";
-  top: -2px;
-}
-
-.tree-view .file .image-icon:before {
-  content: "\f012";
-  top: -2px;
-}
-
-.tree-view .file .compressed-icon:before {
-  content: "\f013";
-  top: -2px;
-}
-
-.tree-view .file .pdf-icon:before {
-  content: "\f014";
-  top: -2px;
-}
-
-.tree-view .file .readme-icon:before {
-  content: "\f007";
-  top: -2px;
-}
-
-.tree-view .file .binary-icon:before {
-  content: "\f094";
-  top: -2px;
-}
-
-.tree-view .file .symlink-icon:before {
-  content: "\f09b";
-  top: -2px;
-}
-
-.tree-view .directory > .header .disclosure-arrow:before {
-  content: "\f05a";
-}
-
-.tree-view .directory.expanded > .header .disclosure-arrow:before {
-  content: "\f05b";
-}
-
-.tree-view-wrapper {
+.tree-view-resizer {
   position: relative;
   height: 100%;
+  overflow: hidden;
   cursor: default;
   -webkit-user-select: none;
   min-width: 50px;
   z-index: 2;
 
-  .tree-view-resizer {
+  .tree-view-resize-handle {
     position: absolute;
     top: 0;
     right: 0;
@@ -158,41 +21,108 @@
   }
 }
 
-.tree-view {
-  position: relative;
-  cursor: default;
-  -webkit-user-select: none;
-  overflow: auto;
+.tree-view-scroller {
   height: 100%;
+  width: 100%;
+  overflow: scroll;
+}
+
+.tree-view {
+  min-width: -webkit-min-content;
+  min-height: 100%;
+  @item-line-height: @line-height-base * 1.25;
+  @disclosure-arrow-size: 12px;
+  @icon-margin: @line-height-base / 4;
+
+  position: relative;
+  padding: 0 @icon-margin;
+  margin-bottom: 0;
+  cursor: default;
 
   .entry {
     text-wrap: none;
     white-space: nowrap;
 
-    & > .header,
-    > .name {
-      z-index: 1;
+    .name {
       position: relative;
-      display: inline-block;
+      z-index: 1;
+    }
+
+    &.selected > .highlight {
+      position: absolute;
+      left: 0;
+      right: 0;
+      height: @item-line-height;
     }
   }
 
-  .selected > .highlight {
-    position: absolute;
-    left: 0;
-    right: 0;
-    height: 24px;
+  .directory {
+    > .header {
+      line-height: @item-line-height;
+      .disclosure-arrow { margin-right: @icon-margin; }
+    }
+
+    .entries {
+      margin-left: 12px;
+    }
   }
 
-  .disclosure-arrow {
-    display: inline-block;
+  .file {
+    line-height: @item-line-height;
+
+    .name {
+      margin-left: @disclosure-arrow-size + @icon-margin;
+    }
+  }
+
+  // icons
+  .name:before {
+    margin-right: @icon-margin;
+    position: relative;
+    top: 1px;
+  }
+
+  .directory > .header {
+    .disclosure-arrow {
+      .mini-icon(arr-collapsed, @disclosure-arrow-size);
+      position: relative;
+    }
+    .directory-icon { .mini-icon(directory); }
+    .repository-icon { .mini-icon(public-repo); }
+    .submodule-icon { .mini-icon(submodule); }
+  }
+
+  .directory.expanded > .header {
+    .disclosure-arrow { .mini-icon(arr-expanded, @disclosure-arrow-size); }
+  }
+
+  .file {
+    .text-icon { .mini-icon(text-file); }
+    .image-icon { .mini-icon(download-media); }
+    .compressed-icon { .mini-icon(download-zip); }
+    .pdf-icon { .mini-icon(download-pdf); }
+    .readme-icon { .mini-icon(readme); }
+    .binary-icon { .mini-icon(binary-file); }
+    .symlink-icon { .mini-icon(symlink); }
   }
 }
 
+
 .tree-view-dialog {
+  padding: 5px;
   position: absolute;
   bottom: 0;
   left: 0;
   right: 0;
   z-index: 99;
+
+  .prompt {
+    padding-bottom: 3px;
+    font-size: 12px;
+    line-height: 16px;
+    &:before { margin-right: @line-height-base / 4; }
+    &.add-file { .mini-icon(new-file); }
+    &.add-directory { .mini-icon(create-directory); }
+    &.prompt.move { .mini-icon(arr-right); }
+  }
 }
diff --git a/src/packages/whitespace/lib/whitespace.coffee b/src/packages/whitespace/lib/whitespace.coffee
index f5c954ba5..a16f9877b 100644
--- a/src/packages/whitespace/lib/whitespace.coffee
+++ b/src/packages/whitespace/lib/whitespace.coffee
@@ -1,11 +1,12 @@
 module.exports =
   activate: ->
-    rootView.eachBuffer (buffer) => @whitespaceBeforeSave(buffer)
+    rootView.eachEditSession (editSession) => @whitespaceBeforeSave(editSession)
 
   configDefaults:
     ensureSingleTrailingNewline: true
 
-  whitespaceBeforeSave: (buffer) ->
+  whitespaceBeforeSave: (editSession) ->
+    buffer = editSession.buffer
     buffer.on 'will-be-saved', ->
       buffer.transact ->
         buffer.scan /[ \t]+$/g, ({replace}) -> replace('')
@@ -16,4 +17,6 @@ module.exports =
             while row and buffer.lineForRow(row) is ''
               buffer.deleteRow(row--)
           else
+            selectedBufferRanges = editSession.getSelectedBufferRanges()
             buffer.append('\n')
+            editSession.setSelectedBufferRanges(selectedBufferRanges)
diff --git a/src/packages/whitespace/spec/whitespace-spec.coffee b/src/packages/whitespace/spec/whitespace-spec.coffee
index 1a0e54f44..35fe6a8ee 100644
--- a/src/packages/whitespace/spec/whitespace-spec.coffee
+++ b/src/packages/whitespace/spec/whitespace-spec.coffee
@@ -79,3 +79,10 @@ describe "Whitespace", ->
       editor.insertText "no trailing newline"
       editor.getBuffer().save()
       expect(editor.getText()).toBe "no trailing newline"
+
+    it "does not move the cursor when the new line is added", ->
+      editor.insertText "foo"
+      expect(editor.getCursorBufferPosition()).toEqual([0,3])
+      editor.getBuffer().save()
+      expect(editor.getText()).toBe "foo\n"
+      expect(editor.getCursorBufferPosition()).toEqual([0,3])
diff --git a/src/stdlib/cson.coffee b/src/stdlib/cson.coffee
index 6d331483d..5b8527d75 100644
--- a/src/stdlib/cson.coffee
+++ b/src/stdlib/cson.coffee
@@ -14,7 +14,8 @@ module.exports =
   readObjectAsync: (path, done) ->
     fs.readFile path, 'utf8', (err, contents) =>
       return done(err) if err?
-      try done(null, @parseObject(path, contents))
+      try
+        done(null, @parseObject(path, contents))
       catch err
         done(err)
 
diff --git a/static/atom.less b/static/atom.less
index f58c62d76..8435756b4 100644
--- a/static/atom.less
+++ b/static/atom.less
@@ -1,86 +1,10 @@
-html, body {
-  width: 100%;
-  height: 100%;
-  overflow: hidden;
-}
-
-#root-view {
-  height: 100%;
-  overflow: hidden;
-  position: relative;
-
-  #horizontal {
-    display: -webkit-flex;
-    height: 100%;
-  }
-
-  #vertical {
-    display: -webkit-flex;
-    -webkit-flex: 1;
-    -webkit-flex-flow: column;
-  }
-}
-
-#panes {
-  position: relative;
-  -webkit-flex: 1;
-
-  .column {
-    position: absolute;
-    top: 0;
-    bottom: 0;
-    left: 0;
-    right: 0;
-    overflow-y: hidden;
-  }
-
-  .row {
-    position: absolute;
-    top: 0;
-    bottom: 0;
-    left: 0;
-    right: 0;
-    overflow-x: hidden;
-  }
-
-  .pane {
-    position: absolute;
-    display: -webkit-flex;
-    -webkit-flex-flow: column;
-    top: 0;
-    bottom: 0;
-    left: 0;
-    right: 0;
-    box-sizing: border-box;
-  }
-
-  .pane .item-views {
-    -webkit-flex: 1;
-    display: -webkit-flex;
-    -webkit-flex-flow: column;
-  }
-
-  .pane .item-views > * {
-    -webkit-flex: 1;
-    min-height: 0;
-  }
-}
-
-@font-face {
-  font-family: 'Octicons Regular';
-  src: url("octicons-regular-webfont.woff") format("woff");
-  font-weight: normal;
-  font-style: normal;
-}
-
-.is-loading {
-  background-image: url(images/spinner.svg);
-  background-repeat: no-repeat;
-  width: 14px;
-  height: 14px;
-  opacity: 0.5;
-  background-size: contain;
-  position: relative;
-  display: inline-block;
-  padding-left: 19px;
+@import "bootstrap/less/bootstrap.less";
+@import "root-view.less";
+@import "overlay.less";
+@import "popover-list.less";
+@import "notification.less";
+@import "markdown.less";
+
+:focus {
+  outline: none;
 }
diff --git a/static/editor.less b/static/editor.less
index 4ac5cb832..61ed9ac1b 100644
--- a/static/editor.less
+++ b/static/editor.less
@@ -30,7 +30,6 @@
   cursor: default;
   min-width: 1em;
   box-sizing: border-box;
-  text-align: right;
 }
 
 .editor .gutter .line-number {
@@ -139,6 +138,10 @@
   position: absolute;
 }
 
+.editor .line {
+  white-space: pre;
+}
+
 .editor .line span {
   vertical-align: top;
 }
@@ -158,11 +161,14 @@
 }
 
 .editor .hidden-input {
+  padding: 0;
+  border: 0;
   position: absolute;
   z-index: -1;
   top: 0;
   left: 0;
   opacity: 0;
+  width: 1px;
 }
 
 .editor .selection .region {
diff --git a/static/image-view.less b/static/image-view.less
index 49c39fbda..ef2deb767 100644
--- a/static/image-view.less
+++ b/static/image-view.less
@@ -6,6 +6,7 @@
   overflow: auto;
 
   img {
+    box-sizing: content-box;
     padding: 25px;
     border: 2px solid;
     background-image: url(images/transparent-background.gif);
diff --git a/static/jasmine.less b/static/jasmine.less
index efcd29038..d90335ad9 100644
--- a/static/jasmine.less
+++ b/static/jasmine.less
@@ -25,7 +25,7 @@ body {
 #HTMLReporter .symbolSummary {
   background-color: #222;
   overflow: hidden;
-  *zoom: 1
+  margin: 0;
 }
 
 #HTMLReporter .symbolSummary li {
diff --git a/static/mega-octicon-utf-codes.less b/static/mega-octicon-utf-codes.less
new file mode 100644
index 000000000..7086023c7
--- /dev/null
+++ b/static/mega-octicon-utf-codes.less
@@ -0,0 +1,171 @@
+@private-repo: "\f26a";
+@public-repo: "\f201";
+@repo-forked: "\f202";
+@create: "\f203";
+@delete: "\f204";
+@push: "\f205";
+@pull: "\f206";
+@readme: "\f207";
+@wiki: "\f207";
+@octocat: "\f208";
+@site-message: "\f209";
+@blacktocat: "\f209";
+@invertocat: "\f20a";
+@download: "\f20b";
+@upload: "\f20c";
+@keyboard: "\f20d";
+@gist: "\f20e";
+@gist-private: "\f20f";
+@code-file: "\f210";
+@download-unknown: "\f210";
+@download-text: "\f211";
+@text-file: "\f211";
+@download-media: "\f212";
+@download-zip: "\f213";
+@download-pdf: "\f214";
+@download-tag: "\f215";
+@tag: "\f215";
+@directory: "\f216";
+@submodule: "\f217";
+@person: "\f218";
+@team: "\f219";
+@member-added: "\f21a";
+@member-removed: "\f21b";
+@follow: "\f21c";
+@watching: "\f21d";
+@unwatch: "\f21e";
+@commit: "\f21f";
+@public-fork: "\f220";
+@fork: "\f220";
+@branch: "\f220";
+@tree: "\f220";
+@private-fork: "\f221";
+@pull-request: "\f222";
+@merge: "\f223";
+@public-mirror: "\f224";
+@private-mirror: "\f225";
+@issue-opened: "\f226";
+@issue-reopened: "\f227";
+@issue-closed: "\f228";
+@issue-comment: "\f229";
+@star: "\f22a";
+@commit-comment: "\f22b";
+@help: "\f22c";
+@exclamation: "\f22d";
+@search-input: "\f22e";
+@advanced-search: "\f22f";
+@notifications: "\f230";
+@account-settings: "\f231";
+@logout: "\f232";
+@admin-tools: "\f233";
+@feed: "\f234";
+@clipboard: "\f235";
+@apple: "\f236";
+@windows: "\f237";
+@ios: "\f238";
+@download-android: "\f239";
+@android: "\f239";
+@confirm: "\f23a";
+@unread-note: "\f23b";
+@read-note: "\f23c";
+@arr-up: "\f23d";
+@arr-right: "\f23e";
+@arr-down: "\f23f";
+@arr-left: "\f240";
+@pin: "\f241";
+@gift: "\f242";
+@graph: "\f243";
+@wrench: "\f244";
+@credit-card: "\f245";
+@time: "\f246";
+@ruby: "\f247";
+@podcast: "\f248";
+@key: "\f249";
+@force-push: "\f24a";
+@sync: "\f24b";
+@clone: "\f24c";
+@diff: "\f24d";
+@watchers: "\f24e";
+@discussion: "\f24f";
+@delete-note: "\f250";
+@remove-close: "\f250";
+@reply: "\f251";
+@mail-status: "\f252";
+@block: "\f253";
+@tag-create: "\f254";
+@tab-delete: "\f255";
+@branch-create: "\f256";
+@branch-delete: "\f257";
+@edit: "\f258";
+@info: "\f259";
+@arr-collapsed: "\f25a";
+@arr-expanded: "\f25b";
+@link: "\f25c";
+@add: "\f25d";
+@reorder: "\f25e";
+@code: "\f25f";
+@location: "\f260";
+@u-list: "\f261";
+@o-list: "\f262";
+@quotemark: "\f263";
+@version: "\f264";
+@brightness: "\f265";
+@fullscreen: "\f266";
+@normalscreen: "\f267";
+@calendar: "\f268";
+@beer: "\f269";
+@secure: "\f26a";
+@lock: "\f26a";
+@added: "\f26b";
+@removed: "\f26c";
+@modified: "\f26d";
+@moved: "\f26e";
+@renamed: "\f26e";
+@add-comment: "\f26f";
+@horizontal-rule: "\f270";
+@arr-right-mini: "\f271";
+@jump-down: "\f272";
+@jump-up: "\f273";
+@reference: "\f274";
+@milestone: "\f275";
+@save-document: "\f276";
+@megaphone: "\f277";
+@chevron: "\f278";
+@gist-forked: "\f279";
+@gist-add: "\f27a";
+@bookmark: "\f27b";
+@filters: "\f27c";
+@dashboard: "\f27d";
+@history: "\f27e";
+@external-link: "\f27f";
+@mute: "\f280";
+@x: "\f281";
+@add-star: "\f282";
+@remove-star: "\f283";
+@circle-slash: "\f284";
+@pulse: "\f285";
+@new-file: "\f286";
+@refresh: "\f287";
+@telescope: "\f288";
+@microscope: "\f289";
+@align: "\f28a";
+@unalign: "\f28b";
+@gist-secret: "\f28c";
+@home: "\f28d";
+@aligned-to: "\f28e";
+@stop-spam: "\f28f";
+@zap: "\f290";
+@bug: "\f291";
+@loading-inner: "\f292";
+@loading-outer: "\f293";
+@binary-file: "\f294";
+@create-directory: "\f295";
+@database: "\f296";
+@server: "\f297";
+@ignored-file: "\f298";
+@ignore: "\f299";
+@ellipsis: "\f29a";
+@symlink: "\f29b";
+@no-newline: "\f29c";
+@hubot: "\f29d";
+@hourglass: "\f29e";
diff --git a/static/mini-octicon-utf-codes.less b/static/mini-octicon-utf-codes.less
new file mode 100644
index 000000000..5a20d3d0a
--- /dev/null
+++ b/static/mini-octicon-utf-codes.less
@@ -0,0 +1,171 @@
+@private-repo: "\f06a";
+@public-repo: "\f001";
+@repo-forked: "\f002";
+@create: "\f003";
+@delete: "\f004";
+@push: "\f005";
+@pull: "\f006";
+@readme: "\f007";
+@wiki: "\f007";
+@octocat: "\f008";
+@site-message: "\f009";
+@blacktocat: "\f009";
+@invertocat: "\f00a";
+@download: "\f00b";
+@upload: "\f00c";
+@keyboard: "\f00d";
+@gist: "\f00e";
+@gist-private: "\f00f";
+@code-file: "\f010";
+@download-unknown: "\f010";
+@download-text: "\f011";
+@text-file: "\f011";
+@download-media: "\f012";
+@download-zip: "\f013";
+@download-pdf: "\f014";
+@download-tag: "\f015";
+@tag: "\f015";
+@directory: "\f016";
+@submodule: "\f017";
+@person: "\f018";
+@team: "\f019";
+@member-added: "\f01a";
+@member-removed: "\f01b";
+@follow: "\f01c";
+@watching: "\f01d";
+@unwatch: "\f01e";
+@commit: "\f01f";
+@public-fork: "\f020";
+@fork: "\f020";
+@branch: "\f020";
+@tree: "\f020";
+@private-fork: "\f021";
+@pull-request: "\f022";
+@merge: "\f023";
+@public-mirror: "\f024";
+@private-mirror: "\f025";
+@issue-opened: "\f026";
+@issue-reopened: "\f027";
+@issue-closed: "\f028";
+@issue-comment: "\f029";
+@star: "\f02a";
+@commit-comment: "\f02b";
+@help: "\f02c";
+@exclamation: "\f02d";
+@search-input: "\f02e";
+@advanced-search: "\f02f";
+@notifications: "\f030";
+@account-settings: "\f031";
+@logout: "\f032";
+@admin-tools: "\f033";
+@feed: "\f034";
+@clipboard: "\f035";
+@apple: "\f036";
+@windows: "\f037";
+@ios: "\f038";
+@download-android: "\f039";
+@android: "\f039";
+@confirm: "\f03a";
+@unread-note: "\f03b";
+@read-note: "\f03c";
+@arr-up: "\f03d";
+@arr-right: "\f03e";
+@arr-down: "\f03f";
+@arr-left: "\f040";
+@pin: "\f041";
+@gift: "\f042";
+@graph: "\f043";
+@wrench: "\f044";
+@credit-card: "\f045";
+@time: "\f046";
+@ruby: "\f047";
+@podcast: "\f048";
+@key: "\f049";
+@force-push: "\f04a";
+@sync: "\f04b";
+@clone: "\f04c";
+@diff: "\f04d";
+@watchers: "\f04e";
+@discussion: "\f04f";
+@delete-note: "\f050";
+@remove-close: "\f050";
+@reply: "\f051";
+@mail-status: "\f052";
+@block: "\f053";
+@tag-create: "\f054";
+@tab-delete: "\f055";
+@branch-create: "\f056";
+@branch-delete: "\f057";
+@edit: "\f058";
+@info: "\f059";
+@arr-collapsed: "\f05a";
+@arr-expanded: "\f05b";
+@link: "\f05c";
+@add: "\f05d";
+@reorder: "\f05e";
+@code: "\f05f";
+@location: "\f060";
+@u-list: "\f061";
+@o-list: "\f062";
+@quotemark: "\f063";
+@version: "\f064";
+@brightness: "\f065";
+@fullscreen: "\f066";
+@normalscreen: "\f067";
+@calendar: "\f068";
+@beer: "\f069";
+@secure: "\f06a";
+@lock: "\f06a";
+@added: "\f06b";
+@removed: "\f06c";
+@modified: "\f06d";
+@moved: "\f06e";
+@renamed: "\f06e";
+@add-comment: "\f06f";
+@horizontal-rule: "\f070";
+@arr-right-mini: "\f071";
+@jump-down: "\f072";
+@jump-up: "\f073";
+@reference: "\f074";
+@milestone: "\f075";
+@save-document: "\f076";
+@megaphone: "\f077";
+@chevron: "\f078";
+@gist-forked: "\f079";
+@gist-add: "\f07a";
+@bookmark: "\f07b";
+@filters: "\f07c";
+@dashboard: "\f07d";
+@history: "\f07e";
+@external-link: "\f07f";
+@mute: "\f080";
+@x: "\f081";
+@add-star: "\f082";
+@remove-star: "\f083";
+@circle-slash: "\f084";
+@pulse: "\f085";
+@new-file: "\f086";
+@refresh: "\f087";
+@telescope: "\f088";
+@microscope: "\f089";
+@align: "\f08a";
+@unalign: "\f08b";
+@gist-secret: "\f08c";
+@home: "\f08d";
+@aligned-to: "\f08e";
+@stop-spam: "\f08f";
+@zap: "\f090";
+@bug: "\f091";
+@loading-inner: "\f092";
+@loading-outer: "\f093";
+@binary-file: "\f094";
+@create-directory: "\f095";
+@database: "\f096";
+@server: "\f097";
+@ignored-file: "\f098";
+@ignore: "\f099";
+@ellipsis: "\f09a";
+@symlink: "\f09b";
+@no-newline: "\f09c";
+@hubot: "\f09d";
+@hourglass: "\f09e";
diff --git a/static/octicon-mixins.less b/static/octicon-mixins.less
new file mode 100644
index 000000000..fa660a6e2
--- /dev/null
+++ b/static/octicon-mixins.less
@@ -0,0 +1,33 @@
+.icon() {
+  font-family: 'Octicons Regular';
+  font-weight: normal;
+  font-style: normal;
+  display: inline-block;
+  line-height: 1;
+  -webkit-font-smoothing: antialiased;
+  line-height: 1;
+  text-decoration: none;
+}
+
+.icon(@size) {
+  .icon;
+  font-size: @size;
+  width: @size;
+  height: @size;
+}
+
+.mini-icon(@name, @size: 16px) {
+  @import "mini-octicon-utf-codes.less";
+  &:before {
+    .icon(@size);
+    content: @@name
+  }
+}
+
+.mega-icon(@name, @size: 32px) {
+  @import "mega-octicon-utf-codes.less";
+  &:before {
+    .icon(@size);
+    content: @@name
+  }
+}
diff --git a/static/reset.less b/static/reset.less
deleted file mode 100644
index 44497b27d..000000000
--- a/static/reset.less
+++ /dev/null
@@ -1,68 +0,0 @@
-/* --------------------------------------------------------------
-
-   reset.css
-   * Resets default browser CSS.
-
--------------------------------------------------------------- */
-
-html {
-  margin:0;
-  padding:0;
-  border:0;
-}
-
-body, div, span, object, iframe,
-h1, h2, h3, h4, h5, h6, p, blockquote, pre,
-a, abbr, acronym, address, code,
-del, dfn, em, img, q, dl, dt, dd, ol, ul, li,
-fieldset, form, label, legend,
-table, caption, tbody, tfoot, thead, tr, th, td,
-article, aside, dialog, figure, footer, header,
-hgroup, nav, section {
-  margin: 0;
-  padding: 0;
-  border: 0;
-  font-size: 100%;
-  font: inherit;
-  vertical-align: baseline;
-}
-
-li {
-  list-style-type: none;
-}
-
-/* This helps to make newer HTML5 elements behave like DIVs in older browers */
-article, aside, details, figcaption, figure, dialog,
-footer, header, hgroup, menu, nav, section {
-    display:block;
-}
-
-/* Line-height should always be unitless! */
-body {
-  line-height: 1.5;
-}
-
-/* Tables still need 'cellspacing="0"' in the markup. */
-table {
-  border-collapse: separate;
-  border-spacing: 0;
-}
-/* float:none prevents the span-x classes from breaking table-cell display */
-caption, th, td {
-  text-align: left;
-  font-weight: normal;
-  float:none !important;
-}
-table, th, td {
-  vertical-align: middle;
-}
-
-/* Remove possible quote marks (") from <q>, <blockquote>. */
-blockquote:before, blockquote:after, q:before, q:after { content: ''; }
-blockquote, q { quotes: "" ""; }
-
-/* Remove annoying border on linked images. */
-a img { border: none; }
-
-/* Remember to define your own focus styles! */
-:focus { outline: 0; }
diff --git a/static/root-view.less b/static/root-view.less
new file mode 100644
index 000000000..f58c62d76
--- /dev/null
+++ b/static/root-view.less
@@ -0,0 +1,86 @@
+html, body {
+  width: 100%;
+  height: 100%;
+  overflow: hidden;
+}
+
+#root-view {
+  height: 100%;
+  overflow: hidden;
+  position: relative;
+
+  #horizontal {
+    display: -webkit-flex;
+    height: 100%;
+  }
+
+  #vertical {
+    display: -webkit-flex;
+    -webkit-flex: 1;
+    -webkit-flex-flow: column;
+  }
+}
+
+#panes {
+  position: relative;
+  -webkit-flex: 1;
+
+  .column {
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+    overflow-y: hidden;
+  }
+
+  .row {
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+    overflow-x: hidden;
+  }
+
+  .pane {
+    position: absolute;
+    display: -webkit-flex;
+    -webkit-flex-flow: column;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+    box-sizing: border-box;
+  }
+
+  .pane .item-views {
+    -webkit-flex: 1;
+    display: -webkit-flex;
+    -webkit-flex-flow: column;
+  }
+
+  .pane .item-views > * {
+    -webkit-flex: 1;
+    min-height: 0;
+  }
+}
+
+@font-face {
+  font-family: 'Octicons Regular';
+  src: url("octicons-regular-webfont.woff") format("woff");
+  font-weight: normal;
+  font-style: normal;
+}
+
+.is-loading {
+  background-image: url(images/spinner.svg);
+  background-repeat: no-repeat;
+  width: 14px;
+  height: 14px;
+  opacity: 0.5;
+  background-size: contain;
+  position: relative;
+  display: inline-block;
+  padding-left: 19px;
+}
diff --git a/static/select-list.less b/static/select-list.less
index 24676a9c2..affeec33c 100644
--- a/static/select-list.less
+++ b/static/select-list.less
@@ -1,61 +1,51 @@
-.select-list ol {
-  border: 1px solid #212121;
-  position: relative;
-  overflow-y: auto;
-  max-height: 312px;
-  margin: 0;
-  padding: 0;
-  line-height: 100%;
-  -webkit-user-select: none;
-  cursor: default;
-}
+@import "octicon-mixins.less";
 
-.select-list ol:empty {
-  border: none;
-}
+.select-list {
+  .error {
+    font-weight: bold;
+  }
 
-.select-list ol li {
-  padding: 10px;
-  box-sizing: border-box;
-  display: block;
-}
+  ol {
+    position: relative;
+    overflow-y: auto;
+    max-height: 312px;
+    margin: 0;
+    padding: 0;
 
-.select-list li .label {
-  display: inline-block;
-}
+    &:empty {
+      border: none;
+    }
 
-.select-list li .right {
-  float: right;
-}
+    li {
+      padding: 10px;
+      display: block;
+    }
 
-.select-list .key-binding {
-  border-radius: 2px;
-  margin-left: 5px;
-  padding: 3px;
-  font-size: 11px;
-}
+    li:last-child {
+      border-bottom: none;
+    }
 
-.select-list ol li:last-child {
-  border-bottom: none;
-}
+    li.active-item {
+      .mini-icon(confirm, 14px);
 
-.select-list .error {
-  font-weight: bold;
-  color: white;
-  text-shadow: 0 1px 0 #4E0000;
-}
+      &:before {
+        margin-right: 5px;
+      }
+    }
 
-.select-list li.active-item:before {
-  font-family: 'Octicons Regular';
-  font-size: 14px;
-  width: 14px;
-  height: 14px;
-  margin-right: 5px;
-  -webkit-font-smoothing: antialiased;
-  color: #9d9d9d;
-  content: '\f03a';
-}
+    li.inactive-item {
+      padding-left: 29px;
+    }
 
-.select-list li.inactive-item {
-  padding-left: 29px;
+    li .right {
+      float: right;
+    }
+
+    .key-binding {
+      border-radius: 2px;
+      margin-left: 5px;
+      padding: 3px;
+      font-size: 11px;
+    }
+  }
 }
diff --git a/themes/atom-dark-ui/atom.less b/themes/atom-dark-ui/atom.less
index 22afd1c83..915e12106 100644
--- a/themes/atom-dark-ui/atom.less
+++ b/themes/atom-dark-ui/atom.less
@@ -1,3 +1,5 @@
+@import "bootstrap/less/mixins.less";
+
 html, body,
 #root-view {
   font: caption;
@@ -23,4 +25,9 @@ html, body,
 
 .wrap-guide {
   background: rgba(150, 150, 150, 0.1);
-}
\ No newline at end of file
+}
+
+.btn {
+  .btn-pseudo-states(#19191a, #1a1b1c);
+  color: #969696;
+}
diff --git a/themes/atom-dark-ui/select-list.less b/themes/atom-dark-ui/select-list.less
index bbe192765..0413d192a 100644
--- a/themes/atom-dark-ui/select-list.less
+++ b/themes/atom-dark-ui/select-list.less
@@ -1,48 +1,60 @@
-.select-list ol li {
-  background-color: #27292b;
-  border-bottom: 1px solid #1e1e1e;
-}
+.select-list {
+  .error {
+    color: white;
+    text-shadow: 0 1px 0 #4E0000;
+  }
 
-.select-list li .label {
-  color: #bbb;
-}
+  ol {
+    border: 1px solid #212121;
 
-.select-list .key-binding {
-  background: -webkit-linear-gradient(
-    rgba(100, 100, 100, 0.5),
-    rgba(70,70,70, 0.5));
-  color: #ccc;
-  -webkit-box-shadow: inset 1px 1px 0 rgba(255, 255, 255, 0.1);
-  display: inline-block;
-  line-height: 100%;
-}
+    li {
+      background-color: #27292b;
+      border-bottom: 1px solid #1e1e1e;
+      color: #bbb;
+    }
 
-.select-list li:hover .label {
-  color: #fff;
-}
+    .key-binding {
+      background: -webkit-linear-gradient(
+        rgba(100, 100, 100, 0.5),
+        rgba(70,70,70, 0.5));
+      color: #ccc;
+      -webkit-box-shadow: inset 1px 1px 0 rgba(255, 255, 255, 0.1);
+      display: inline-block;
+      line-height: 100%;
+    }
 
-.select-list ol .selected {
-  background-image: -webkit-linear-gradient(#7e7e7e, #737373);
-}
+    li.active-item:before {
+      color: #9d9d9d;
+    }
 
-.select-list .right,
-.select-list .directory {
-  color: #777;
-}
+    li:hover {
+      color: #fff;
+    }
 
-.select-list ol .selected .label {
-  color: #fff;
-}
+    .selected {
+      background-image: -webkit-linear-gradient(#7e7e7e, #737373);
+    }
 
-.select-list ol .selected .right,
-.select-list ol .selected .directory {
-  color: #ccc;
-}
+    .right,
+    .directory {
+      color: #777;
+    }
 
-.select-list .modified {
-  color: #f78a46;
-}
+    .selected {
+      color: #fff;
+    }
 
-.select-list .new {
-  color: #5293d8;
+    .selected .right,
+    .selected .directory {
+      color: #ccc;
+    }
+
+    .modified {
+      color: #f78a46;
+    }
+
+    .new {
+      color: #5293d8;
+    }
+  }
 }
diff --git a/themes/atom-light-ui/atom.less b/themes/atom-light-ui/atom.less
index 76f2e989b..38c6e453d 100644
--- a/themes/atom-light-ui/atom.less
+++ b/themes/atom-light-ui/atom.less
@@ -1,3 +1,5 @@
+@import "bootstrap/less/mixins.less";
+
 html, body,
 #root-view {
   font: caption;
@@ -23,4 +25,14 @@ html, body,
 
 .wrap-guide {
   background: rgba(150, 150, 150, 0.1);
-}
\ No newline at end of file
+}
+
+.btn {
+  .btn-pseudo-states(#cbcbcb, #b3b3b3);
+  color: #444;
+
+  &:hover,
+  &:focus {
+    color: #222;
+  }
+}
diff --git a/themes/atom-light-ui/select-list.less b/themes/atom-light-ui/select-list.less
index 54a8934aa..1864cd06c 100644
--- a/themes/atom-light-ui/select-list.less
+++ b/themes/atom-light-ui/select-list.less
@@ -3,39 +3,48 @@
   border: 1px solid #c6c6c6;
   color: #323232;
   box-shadow: 0 0 10px #555;
-}
 
-.select-list ol {
-  border: 1px solid #d2d2d2;
-}
+  .error {
+    color: white;
+    text-shadow: 0 1px 0 #4E0000;
+  }
 
-.select-list ol li {
-  background-color: #f5f5f5;
-  border-bottom: 1px solid #ccc;
-}
+  ol {
+    border: 1px solid #d2d2d2;
 
-.select-list li:hover {
-  background-color: #f9f9f9;
-}
+    li {
+      background-color: #f5f5f5;
+      border-bottom: 1px solid #ccc;
+    }
 
-.select-list ol .selected {
-  background-color: #e0e0e0;
-}
+    li:hover {
+      background-color: #f9f9f9;
+    }
 
-.select-list .right,
-.select-list .directory {
-  color: #777;
-}
+    li.active-item:before {
+      color: #9d9d9d;
+    }
 
-.select-list ol .selected .right,
-.select-list ol .selected .directory {
-  color: #333;
-}
+    .selected {
+      background-color: #e0e0e0;
+    }
 
-.select-list .modified {
-  color: #f78a46;
-}
+    .selected .right,
+    .selected .directory {
+      color: #333;
+    }
 
-.select-list .new {
-  color: #5293d8;
+    .right,
+    .directory {
+      color: #777;
+    }
+
+    .modified {
+      color: #f78a46;
+    }
+
+    .new {
+      color: #5293d8;
+    }
+  }
 }
diff --git a/vendor/bootstrap b/vendor/bootstrap
new file mode 160000
index 000000000..991a353a2
--- /dev/null
+++ b/vendor/bootstrap
@@ -0,0 +1 @@
+Subproject commit 991a353a26f9f7a7399591985af0afb191eee6ee
diff --git a/vendor/less.js b/vendor/less.js
deleted file mode 100644
index 59629068d..000000000
--- a/vendor/less.js
+++ /dev/null
@@ -1,5078 +0,0 @@
-// Modified
-//
-// Added
-//     module.exports.less = window.less = less = {}
-//     less.tree = tree = {}
-//     less.mode = 'browser'
-//
-// LESS - Leaner CSS v1.4.0
-// http://lesscss.org
-//
-// Copyright (c) 2009-2013, Alexis Sellier
-// Licensed under the Apache 2.0 License.
-//
-(function (window, undefined) {
-//
-// Stub out `require` in the browser
-//
-function require(arg) {
-    return window.less[arg.split('/')[1]];
-};
-
-// ecma-5.js
-//
-// -- kriskowal Kris Kowal Copyright (C) 2009-2010 MIT License
-// -- tlrobinson Tom Robinson
-// dantman Daniel Friesen
-
-//
-// Array
-//
-if (!Array.isArray) {
-    Array.isArray = function(obj) {
-        return Object.prototype.toString.call(obj) === "[object Array]" ||
-               (obj instanceof Array);
-    };
-}
-if (!Array.prototype.forEach) {
-    Array.prototype.forEach =  function(block, thisObject) {
-        var len = this.length >>> 0;
-        for (var i = 0; i < len; i++) {
-            if (i in this) {
-                block.call(thisObject, this[i], i, this);
-            }
-        }
-    };
-}
-if (!Array.prototype.map) {
-    Array.prototype.map = function(fun /*, thisp*/) {
-        var len = this.length >>> 0;
-        var res = new Array(len);
-        var thisp = arguments[1];
-
-        for (var i = 0; i < len; i++) {
-            if (i in this) {
-                res[i] = fun.call(thisp, this[i], i, this);
-            }
-        }
-        return res;
-    };
-}
-if (!Array.prototype.filter) {
-    Array.prototype.filter = function (block /*, thisp */) {
-        var values = [];
-        var thisp = arguments[1];
-        for (var i = 0; i < this.length; i++) {
-            if (block.call(thisp, this[i])) {
-                values.push(this[i]);
-            }
-        }
-        return values;
-    };
-}
-if (!Array.prototype.reduce) {
-    Array.prototype.reduce = function(fun /*, initial*/) {
-        var len = this.length >>> 0;
-        var i = 0;
-
-        // no value to return if no initial value and an empty array
-        if (len === 0 && arguments.length === 1) throw new TypeError();
-
-        if (arguments.length >= 2) {
-            var rv = arguments[1];
-        } else {
-            do {
-                if (i in this) {
-                    rv = this[i++];
-                    break;
-                }
-                // if array contains no values, no initial value to return
-                if (++i >= len) throw new TypeError();
-            } while (true);
-        }
-        for (; i < len; i++) {
-            if (i in this) {
-                rv = fun.call(null, rv, this[i], i, this);
-            }
-        }
-        return rv;
-    };
-}
-if (!Array.prototype.indexOf) {
-    Array.prototype.indexOf = function (value /*, fromIndex */ ) {
-        var length = this.length;
-        var i = arguments[1] || 0;
-
-        if (!length)     return -1;
-        if (i >= length) return -1;
-        if (i < 0)       i += length;
-
-        for (; i < length; i++) {
-            if (!Object.prototype.hasOwnProperty.call(this, i)) { continue }
-            if (value === this[i]) return i;
-        }
-        return -1;
-    };
-}
-
-//
-// Object
-//
-if (!Object.keys) {
-    Object.keys = function (object) {
-        var keys = [];
-        for (var name in object) {
-            if (Object.prototype.hasOwnProperty.call(object, name)) {
-                keys.push(name);
-            }
-        }
-        return keys;
-    };
-}
-
-//
-// String
-//
-if (!String.prototype.trim) {
-    String.prototype.trim = function () {
-        return String(this).replace(/^\s\s*/, '').replace(/\s\s*$/, '');
-    };
-}
-var less, tree, charset;
-
-module.exports.less = window.less = less = {}
-less.tree = tree = {}
-less.mode = 'browser'
-//
-// less.js - parser
-//
-//    A relatively straight-forward predictive parser.
-//    There is no tokenization/lexing stage, the input is parsed
-//    in one sweep.
-//
-//    To make the parser fast enough to run in the browser, several
-//    optimization had to be made:
-//
-//    - Matching and slicing on a huge input is often cause of slowdowns.
-//      The solution is to chunkify the input into smaller strings.
-//      The chunks are stored in the `chunks` var,
-//      `j` holds the current chunk index, and `current` holds
-//      the index of the current chunk in relation to `input`.
-//      This gives us an almost 4x speed-up.
-//
-//    - In many cases, we don't need to match individual tokens;
-//      for example, if a value doesn't hold any variables, operations
-//      or dynamic references, the parser can effectively 'skip' it,
-//      treating it as a literal.
-//      An example would be '1px solid #000' - which evaluates to itself,
-//      we don't need to know what the individual components are.
-//      The drawback, of course is that you don't get the benefits of
-//      syntax-checking on the CSS. This gives us a 50% speed-up in the parser,
-//      and a smaller speed-up in the code-gen.
-//
-//
-//    Token matching is done with the `$` function, which either takes
-//    a terminal string or regexp, or a non-terminal function to call.
-//    It also takes care of moving all the indices forwards.
-//
-//
-less.Parser = function Parser(env) {
-    var input,       // LeSS input string
-        i,           // current index in `input`
-        j,           // current chunk
-        temp,        // temporarily holds a chunk's state, for backtracking
-        memo,        // temporarily holds `i`, when backtracking
-        furthest,    // furthest index the parser has gone to
-        chunks,      // chunkified input
-        current,     // index of current chunk, in `input`
-        parser;
-
-    var that = this;
-
-    // Top parser on an import tree must be sure there is one "env"
-    // which will then be passed around by reference.
-    if (!(env instanceof tree.parseEnv)) {
-        env = new tree.parseEnv(env);
-    }
-
-    if (!env.currentDirectory && env.filename) {
-        // only works for node, only used for node
-        env.currentDirectory = env.filename.replace(/[^\/\\]*$/, "");
-    }
-
-    // This function is called after all files
-    // have been imported through `@import`.
-    var finish = function () {};
-
-    var imports = this.imports = {
-        paths: env.paths || [],  // Search paths, when importing
-        queue: [],               // Files which haven't been imported yet
-        files: env.files,        // Holds the imported parse trees
-        contents: env.contents,  // Holds the imported file contents
-        mime:  env.mime,         // MIME type of .less files
-        error: null,             // Error in parsing/evaluating an import
-        push: function (path, callback) {
-            var that = this;
-            this.queue.push(path);
-
-            //
-            // Import a file asynchronously
-            //
-            less.Parser.importer(path, this.paths, function (e, root, fullPath) {
-                that.queue.splice(that.queue.indexOf(path), 1); // Remove the path from the queue
-
-                var imported = fullPath in that.files;
-
-                that.files[fullPath] = root;                        // Store the root
-
-                if (e && !that.error) { that.error = e; }
-
-                callback(e, root, imported);
-
-                if (that.queue.length === 0) { finish(that.error); }       // Call `finish` if we're done importing
-            }, env);
-        }
-    };
-
-    function save()    { temp = chunks[j], memo = i, current = i; }
-    function restore() { chunks[j] = temp, i = memo, current = i; }
-
-    function sync() {
-        if (i > current) {
-            chunks[j] = chunks[j].slice(i - current);
-            current = i;
-        }
-    }
-    function isWhitespace(c) {
-        // Could change to \s?
-        var code = c.charCodeAt(0);
-        return code === 32 || code === 10 || code === 9;
-    }
-    //
-    // Parse from a token, regexp or string, and move forward if match
-    //
-    function $(tok) {
-        var match, args, length, index, k;
-
-        //
-        // Non-terminal
-        //
-        if (tok instanceof Function) {
-            return tok.call(parser.parsers);
-        //
-        // Terminal
-        //
-        //     Either match a single character in the input,
-        //     or match a regexp in the current chunk (chunk[j]).
-        //
-        } else if (typeof(tok) === 'string') {
-            match = input.charAt(i) === tok ? tok : null;
-            length = 1;
-            sync ();
-        } else {
-            sync ();
-
-            if (match = tok.exec(chunks[j])) {
-                length = match[0].length;
-            } else {
-                return null;
-            }
-        }
-
-        // The match is confirmed, add the match length to `i`,
-        // and consume any extra white-space characters (' ' || '\n')
-        // which come after that. The reason for this is that LeSS's
-        // grammar is mostly white-space insensitive.
-        //
-        if (match) {
-            skipWhitespace(length);
-
-            if(typeof(match) === 'string') {
-                return match;
-            } else {
-                return match.length === 1 ? match[0] : match;
-            }
-        }
-    }
-
-    function skipWhitespace(length) {
-        var oldi = i, oldj = j,
-            endIndex = i + chunks[j].length,
-            mem = i += length;
-
-        while (i < endIndex) {
-            if (! isWhitespace(input.charAt(i))) { break }
-            i++;
-        }
-        chunks[j] = chunks[j].slice(length + (i - mem));
-        current = i;
-
-        if (chunks[j].length === 0 && j < chunks.length - 1) { j++ }
-
-        return oldi !== i || oldj !== j;
-    }
-
-    function expect(arg, msg) {
-        var result = $(arg);
-        if (! result) {
-            error(msg || (typeof(arg) === 'string' ? "expected '" + arg + "' got '" + input.charAt(i) + "'"
-                                                   : "unexpected token"));
-        } else {
-            return result;
-        }
-    }
-
-    function error(msg, type) {
-        var e = new Error(msg);
-        e.index = i;
-        e.type = type || 'Syntax';
-        throw e;
-    }
-
-    // Same as $(), but don't change the state of the parser,
-    // just return the match.
-    function peek(tok) {
-        if (typeof(tok) === 'string') {
-            return input.charAt(i) === tok;
-        } else {
-            if (tok.test(chunks[j])) {
-                return true;
-            } else {
-                return false;
-            }
-        }
-    }
-
-    function getInput(e, env) {
-        if (e.filename && env.filename && (e.filename !== env.filename)) {
-            return parser.imports.contents[e.filename];
-        } else {
-            return input;
-        }
-    }
-
-    function getLocation(index, input) {
-        for (var n = index, column = -1;
-                 n >= 0 && input.charAt(n) !== '\n';
-                 n--) { column++ }
-
-        return { line:   typeof(index) === 'number' ? (input.slice(0, index).match(/\n/g) || "").length : null,
-                 column: column };
-    }
-
-    function getFileName(e) {
-        if(less.mode === 'browser' || less.mode === 'rhino')
-            return e.filename;
-        else
-            return require('path').resolve(e.filename);
-    }
-
-    function getDebugInfo(index, inputStream, e) {
-        return {
-            lineNumber: getLocation(index, inputStream).line + 1,
-            fileName: getFileName(e)
-        };
-    }
-
-    function LessError(e, env) {
-        var input = getInput(e, env),
-            loc = getLocation(e.index, input),
-            line = loc.line,
-            col  = loc.column,
-            lines = input.split('\n');
-
-        this.type = e.type || 'Syntax';
-        this.message = e.message;
-        this.filename = e.filename || env.filename;
-        this.index = e.index;
-        this.line = typeof(line) === 'number' ? line + 1 : null;
-        this.callLine = e.call && (getLocation(e.call, input).line + 1);
-        this.callExtract = lines[getLocation(e.call, input).line];
-        this.stack = e.stack;
-        this.column = col;
-        this.extract = [
-            lines[line - 1],
-            lines[line],
-            lines[line + 1]
-        ];
-    }
-
-    this.env = env = env || {};
-
-    // The optimization level dictates the thoroughness of the parser,
-    // the lower the number, the less nodes it will create in the tree.
-    // This could matter for debugging, or if you want to access
-    // the individual nodes in the tree.
-    this.optimization = ('optimization' in this.env) ? this.env.optimization : 1;
-
-    this.env.filename = this.env.filename || null;
-
-    //
-    // The Parser
-    //
-    return parser = {
-
-        imports: imports,
-        //
-        // Parse an input string into an abstract syntax tree,
-        // call `callback` when done.
-        //
-        parse: function (str, callback) {
-            var root, start, end, zone, line, lines, buff = [], c, error = null;
-
-            i = j = current = furthest = 0;
-            input = str.replace(/\r\n/g, '\n');
-
-            // Remove potential UTF Byte Order Mark
-            input = input.replace(/^\uFEFF/, '');
-
-            // Split the input into chunks.
-            chunks = (function (chunks) {
-                var j = 0,
-                    skip = /(?:@\{[\w-]+\}|[^"'`\{\}\/\(\)\\])+/g,
-                    comment = /\/\*(?:[^*]|\*+[^\/*])*\*+\/|\/\/.*/g,
-                    string = /"((?:[^"\\\r\n]|\\.)*)"|'((?:[^'\\\r\n]|\\.)*)'|`((?:[^`]|\\.)*)`/g,
-                    level = 0,
-                    match,
-                    chunk = chunks[0],
-                    inParam;
-
-                for (var i = 0, c, cc; i < input.length;) {
-                    skip.lastIndex = i;
-                    if (match = skip.exec(input)) {
-                        if (match.index === i) {
-                            i += match[0].length;
-                            chunk.push(match[0]);
-                        }
-                    }
-                    c = input.charAt(i);
-                    comment.lastIndex = string.lastIndex = i;
-
-                    if (match = string.exec(input)) {
-                        if (match.index === i) {
-                            i += match[0].length;
-                            chunk.push(match[0]);
-                            continue;
-                        }
-                    }
-
-                    if (!inParam && c === '/') {
-                        cc = input.charAt(i + 1);
-                        if (cc === '/' || cc === '*') {
-                            if (match = comment.exec(input)) {
-                                if (match.index === i) {
-                                    i += match[0].length;
-                                    chunk.push(match[0]);
-                                    continue;
-                                }
-                            }
-                        }
-                    }
-
-                    switch (c) {
-                        case '{': if (! inParam) { level ++;        chunk.push(c);                           break }
-                        case '}': if (! inParam) { level --;        chunk.push(c); chunks[++j] = chunk = []; break }
-                        case '(': if (! inParam) { inParam = true;  chunk.push(c);                           break }
-                        case ')': if (  inParam) { inParam = false; chunk.push(c);                           break }
-                        default:                                    chunk.push(c);
-                    }
-
-                    i++;
-                }
-                if (level != 0) {
-                    error = new(LessError)({
-                        index: i-1,
-                        type: 'Parse',
-                        message: (level > 0) ? "missing closing `}`" : "missing opening `{`",
-                        filename: env.filename
-                    }, env);
-                }
-
-                return chunks.map(function (c) { return c.join('') });;
-            })([[]]);
-
-            if (error) {
-                return callback(new(LessError)(error, env));
-            }
-
-            // Start with the primary rule.
-            // The whole syntax tree is held under a Ruleset node,
-            // with the `root` property set to true, so no `{}` are
-            // output. The callback is called when the input is parsed.
-            try {
-                root = new(tree.Ruleset)([], $(this.parsers.primary));
-                root.root = true;
-            } catch (e) {
-                return callback(new(LessError)(e, env));
-            }
-
-            root.toCSS = (function (evaluate) {
-                var line, lines, column;
-
-                return function (options, variables) {
-                    options = options || {};
-                    var importError,
-                        evalEnv = new tree.evalEnv(options);
-
-                    //
-                    // Allows setting variables with a hash, so:
-                    //
-                    //   `{ color: new(tree.Color)('#f01') }` will become:
-                    //
-                    //   new(tree.Rule)('@color',
-                    //     new(tree.Value)([
-                    //       new(tree.Expression)([
-                    //         new(tree.Color)('#f01')
-                    //       ])
-                    //     ])
-                    //   )
-                    //
-                    if (typeof(variables) === 'object' && !Array.isArray(variables)) {
-                        variables = Object.keys(variables).map(function (k) {
-                            var value = variables[k];
-
-                            if (! (value instanceof tree.Value)) {
-                                if (! (value instanceof tree.Expression)) {
-                                    value = new(tree.Expression)([value]);
-                                }
-                                value = new(tree.Value)([value]);
-                            }
-                            return new(tree.Rule)('@' + k, value, false, 0);
-                        });
-                        evalEnv.frames = [new(tree.Ruleset)(null, variables)];
-                    }
-
-                    try {
-                        var css = evaluate.call(this, evalEnv)
-                                          .toCSS([], {
-                                compress: options.compress || false,
-                                dumpLineNumbers: env.dumpLineNumbers,
-                                strictUnits: options.strictUnits === false ? false : true});
-                    } catch (e) {
-                        throw new(LessError)(e, env);
-                    }
-
-                    if (options.yuicompress && less.mode === 'node') {
-                        return require('ycssmin').cssmin(css);
-                    } else if (options.compress) {
-                        return css.replace(/(\s)+/g, "$1");
-                    } else {
-                        return css;
-                    }
-                };
-            })(root.eval);
-
-            // If `i` is smaller than the `input.length - 1`,
-            // it means the parser wasn't able to parse the whole
-            // string, so we've got a parsing error.
-            //
-            // We try to extract a \n delimited string,
-            // showing the line where the parse error occured.
-            // We split it up into two parts (the part which parsed,
-            // and the part which didn't), so we can color them differently.
-            if (i < input.length - 1) {
-                i = furthest;
-                lines = input.split('\n');
-                line = (input.slice(0, i).match(/\n/g) || "").length + 1;
-
-                for (var n = i, column = -1; n >= 0 && input.charAt(n) !== '\n'; n--) { column++ }
-
-                error = {
-                    type: "Parse",
-                    message: "Unrecognised input",
-                    index: i,
-                    filename: env.filename,
-                    line: line,
-                    column: column,
-                    extract: [
-                        lines[line - 2],
-                        lines[line - 1],
-                        lines[line]
-                    ]
-                };
-            }
-
-            finish = function (e) {
-                e = error || e || parser.imports.error;
-
-                if (e) {
-                    if (!(e instanceof LessError)) {
-                        e = new(LessError)(e, env);
-                    }
-
-                    callback(e);
-                }
-                else {
-                    callback(null, root);
-                }
-            };
-
-            if (this.imports.queue.length === 0) {
-                finish();
-            }
-        },
-
-        //
-        // Here in, the parsing rules/functions
-        //
-        // The basic structure of the syntax tree generated is as follows:
-        //
-        //   Ruleset ->  Rule -> Value -> Expression -> Entity
-        //
-        // Here's some LESS code:
-        //
-        //    .class {
-        //      color: #fff;
-        //      border: 1px solid #000;
-        //      width: @w + 4px;
-        //      > .child {...}
-        //    }
-        //
-        // And here's what the parse tree might look like:
-        //
-        //     Ruleset (Selector '.class', [
-        //         Rule ("color",  Value ([Expression [Color #fff]]))
-        //         Rule ("border", Value ([Expression [Dimension 1px][Keyword "solid"][Color #000]]))
-        //         Rule ("width",  Value ([Expression [Operation "+" [Variable "@w"][Dimension 4px]]]))
-        //         Ruleset (Selector [Element '>', '.child'], [...])
-        //     ])
-        //
-        //  In general, most rules will try to parse a token with the `$()` function, and if the return
-        //  value is truly, will return a new node, of the relevant type. Sometimes, we need to check
-        //  first, before parsing, that's when we use `peek()`.
-        //
-        parsers: {
-            //
-            // The `primary` rule is the *entry* and *exit* point of the parser.
-            // The rules here can appear at any level of the parse tree.
-            //
-            // The recursive nature of the grammar is an interplay between the `block`
-            // rule, which represents `{ ... }`, the `ruleset` rule, and this `primary` rule,
-            // as represented by this simplified grammar:
-            //
-            //     primary  →  (ruleset | rule)+
-            //     ruleset  →  selector+ block
-            //     block    →  '{' primary '}'
-            //
-            // Only at one point is the primary rule not called from the
-            // block rule: at the root level.
-            //
-            primary: function () {
-                var node, root = [];
-
-                while ((node = $(this.extendRule) || $(this.mixin.definition) || $(this.rule)    ||  $(this.ruleset) ||
-                               $(this.mixin.call)       || $(this.comment) ||  $(this.directive))
-                               || $(/^[\s\n]+/) || $(/^;+/)) {
-                    node && root.push(node);
-                }
-                return root;
-            },
-
-            // We create a Comment node for CSS comments `/* */`,
-            // but keep the LeSS comments `//` silent, by just skipping
-            // over them.
-            comment: function () {
-                var comment;
-
-                if (input.charAt(i) !== '/') return;
-
-                if (input.charAt(i + 1) === '/') {
-                    return new(tree.Comment)($(/^\/\/.*/), true);
-                } else if (comment = $(/^\/\*(?:[^*]|\*+[^\/*])*\*+\/\n?/)) {
-                    return new(tree.Comment)(comment);
-                }
-            },
-
-            //
-            // Entities are tokens which can be found inside an Expression
-            //
-            entities: {
-                //
-                // A string, which supports escaping " and '
-                //
-                //     "milky way" 'he\'s the one!'
-                //
-                quoted: function () {
-                    var str, j = i, e;
-
-                    if (input.charAt(j) === '~') { j++, e = true } // Escaped strings
-                    if (input.charAt(j) !== '"' && input.charAt(j) !== "'") return;
-
-                    e && $('~');
-
-                    if (str = $(/^"((?:[^"\\\r\n]|\\.)*)"|'((?:[^'\\\r\n]|\\.)*)'/)) {
-                        return new(tree.Quoted)(str[0], str[1] || str[2], e);
-                    }
-                },
-
-                //
-                // A catch-all word, such as:
-                //
-                //     black border-collapse
-                //
-                keyword: function () {
-                    var k;
-
-                    if (k = $(/^[_A-Za-z-][_A-Za-z0-9-]*/)) {
-                        if (tree.colors.hasOwnProperty(k)) {
-                            // detect named color
-                            return new(tree.Color)(tree.colors[k].slice(1));
-                        } else {
-                            return new(tree.Keyword)(k);
-                        }
-                    }
-                },
-
-                //
-                // A function call
-                //
-                //     rgb(255, 0, 255)
-                //
-                // We also try to catch IE's `alpha()`, but let the `alpha` parser
-                // deal with the details.
-                //
-                // The arguments are parsed with the `entities.arguments` parser.
-                //
-                call: function () {
-                    var name, nameLC, args, alpha_ret, index = i;
-
-                    if (! (name = /^([\w-]+|%|progid:[\w\.]+)\(/.exec(chunks[j]))) return;
-
-                    name = name[1];
-                    nameLC = name.toLowerCase();
-
-                    if (nameLC === 'url') { return null }
-                    else                  { i += name.length }
-
-                    if (nameLC === 'alpha') {
-                        alpha_ret = $(this.alpha);
-                        if(typeof alpha_ret !== 'undefined') {
-                            return alpha_ret;
-                        }
-                    }
-
-                    $('('); // Parse the '(' and consume whitespace.
-
-                    args = $(this.entities.arguments);
-
-                    if (! $(')')) {
-                        return;
-                    }
-
-                    if (name) { return new(tree.Call)(name, args, index, env.filename, env.rootpath, env.currentDirectory); }
-                },
-                arguments: function () {
-                    var args = [], arg;
-
-                    while (arg = $(this.entities.assignment) || $(this.expression)) {
-                        args.push(arg);
-                        if (! $(',')) { break }
-                    }
-                    return args;
-                },
-                literal: function () {
-                    return $(this.entities.dimension) ||
-                           $(this.entities.color) ||
-                           $(this.entities.quoted) ||
-                           $(this.entities.unicodeDescriptor);
-                },
-
-                // Assignments are argument entities for calls.
-                // They are present in ie filter properties as shown below.
-                //
-                //     filter: progid:DXImageTransform.Microsoft.Alpha( *opacity=50* )
-                //
-
-                assignment: function () {
-                    var key, value;
-                    if ((key = $(/^\w+(?=\s?=)/i)) && $('=') && (value = $(this.entity))) {
-                        return new(tree.Assignment)(key, value);
-                    }
-                },
-
-                //
-                // Parse url() tokens
-                //
-                // We use a specific rule for urls, because they don't really behave like
-                // standard function calls. The difference is that the argument doesn't have
-                // to be enclosed within a string, so it can't be parsed as an Expression.
-                //
-                url: function () {
-                    var value;
-
-                    if (input.charAt(i) !== 'u' || !$(/^url\(/)) return;
-                    value = $(this.entities.quoted)  || $(this.entities.variable) ||
-                            $(/^(?:(?:\\[\(\)'"])|[^\(\)'"])+/) || "";
-
-                    expect(')');
-
-                    return new(tree.URL)((value.value != null || value instanceof tree.Variable)
-                                        ? value : new(tree.Anonymous)(value), env.rootpath);
-                },
-
-                //
-                // A Variable entity, such as `@fink`, in
-                //
-                //     width: @fink + 2px
-                //
-                // We use a different parser for variable definitions,
-                // see `parsers.variable`.
-                //
-                variable: function () {
-                    var name, index = i;
-
-                    if (input.charAt(i) === '@' && (name = $(/^@@?[\w-]+/))) {
-                        return new(tree.Variable)(name, index, env.filename);
-                    }
-                },
-
-                // A variable entity useing the protective {} e.g. @{var}
-                variableCurly: function () {
-                    var name, curly, index = i;
-
-                    if (input.charAt(i) === '@' && (curly = $(/^@\{([\w-]+)\}/))) {
-                        return new(tree.Variable)("@" + curly[1], index, env.filename);
-                    }
-                },
-
-                //
-                // A Hexadecimal color
-                //
-                //     #4F3C2F
-                //
-                // `rgb` and `hsl` colors are parsed through the `entities.call` parser.
-                //
-                color: function () {
-                    var rgb;
-
-                    if (input.charAt(i) === '#' && (rgb = $(/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})/))) {
-                        return new(tree.Color)(rgb[1]);
-                    }
-                },
-
-                //
-                // A Dimension, that is, a number and a unit
-                //
-                //     0.5em 95%
-                //
-                dimension: function () {
-                    var value, c = input.charCodeAt(i);
-                    //Is the first char of the dimension 0-9, '.', '+' or '-'
-                    if ((c > 57 || c < 43) || c === 47 || c == 44) return;
-
-                    if (value = $(/^([+-]?\d*\.?\d+)(%|[a-z]+)?/)) {
-                        return new(tree.Dimension)(value[1], value[2]);
-                    }
-                },
-
-                //
-                // A unicode descriptor, as is used in unicode-range
-                //
-                // U+0??  or U+00A1-00A9
-                //
-                unicodeDescriptor: function () {
-                    var ud;
-
-                    if (ud = $(/^U\+[0-9a-fA-F?]+(\-[0-9a-fA-F?]+)?/)) {
-                        return new(tree.UnicodeDescriptor)(ud[0]);
-                    }
-                },
-
-                //
-                // JavaScript code to be evaluated
-                //
-                //     `window.location.href`
-                //
-                javascript: function () {
-                    var str, j = i, e;
-
-                    if (input.charAt(j) === '~') { j++, e = true } // Escaped strings
-                    if (input.charAt(j) !== '`') { return }
-
-                    e && $('~');
-
-                    if (str = $(/^`([^`]*)`/)) {
-                        return new(tree.JavaScript)(str[1], i, e);
-                    }
-                }
-            },
-
-            //
-            // The variable part of a variable definition. Used in the `rule` parser
-            //
-            //     @fink:
-            //
-            variable: function () {
-                var name;
-
-                if (input.charAt(i) === '@' && (name = $(/^(@[\w-]+)\s*:/))) { return name[1] }
-            },
-
-            //
-            // extend syntax - used to extend selectors
-            //
-            extend: function(isRule) {
-                var elements = [], e, args, index = i;
-
-                if (!$(isRule ? /^&:extend\(/ : /^:extend\(/)) { return; }
-
-                while (e = $(/^[#.](?:[\w-]|\\(?:[a-fA-F0-9]{1,6} ?|[^a-fA-F0-9]))+/)) {
-                    elements.push(new(tree.Element)(null, e, i));
-                }
-
-                expect(/^\)/);
-
-                if (isRule) {
-                    expect(/^;/);
-                }
-
-                return new(tree.Extend)(elements, index);
-            },
-
-            //
-            // extendRule - used in a rule to extend all the parent selectors
-            //
-            extendRule: function() {
-                return this.extend(true);
-            },
-
-            //
-            // Mixins
-            //
-            mixin: {
-                //
-                // A Mixin call, with an optional argument list
-                //
-                //     #mixins > .square(#fff);
-                //     .rounded(4px, black);
-                //     .button;
-                //
-                // The `while` loop is there because mixins can be
-                // namespaced, but we only support the child and descendant
-                // selector for now.
-                //
-                call: function () {
-                    var elements = [], e, c, argsSemiColon = [], argsComma = [], args, delim, arg, nameLoop, expressions, isSemiColonSeperated, expressionContainsNamed, index = i, s = input.charAt(i), name, value, important = false;
-
-                    if (s !== '.' && s !== '#') { return }
-
-                    save(); // stop us absorbing part of an invalid selector
-
-                    while (e = $(/^[#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/)) {
-                        elements.push(new(tree.Element)(c, e, i));
-                        c = $('>');
-                    }
-                    if ($('(')) {
-                        expressions = [];
-                        while (arg = $(this.expression)) {
-                            nameLoop = null;
-                            arg.throwAwayComments();
-                            value = arg;
-
-                            // Variable
-                            if (arg.value.length == 1) {
-                                var val = arg.value[0];
-                                if (val instanceof tree.Variable) {
-                                    if ($(':')) {
-                                        if (expressions.length > 0) {
-                                            if (isSemiColonSeperated) {
-                                                error("Cannot mix ; and , as delimiter types");
-                                            }
-                                            expressionContainsNamed = true;
-                                        }
-                                        value = expect(this.expression);
-                                        nameLoop = (name = val.name);
-                                    }
-                                }
-                            }
-
-                            expressions.push(value);
-
-                            argsComma.push({ name: nameLoop, value: value });
-
-                            if ($(',')) {
-                                continue;
-                            }
-
-                            if ($(';') || isSemiColonSeperated) {
-
-                                if (expressionContainsNamed) {
-                                    error("Cannot mix ; and , as delimiter types");
-                                }
-
-                                isSemiColonSeperated = true;
-
-                                if (expressions.length > 1) {
-                                    value = new(tree.Value)(expressions);
-                                }
-                                argsSemiColon.push({ name: name, value: value });
-
-                                name = null;
-                                expressions = [];
-                                expressionContainsNamed = false;
-                            }
-                        }
-
-                        expect(')');
-                    }
-
-                    args = isSemiColonSeperated ? argsSemiColon : argsComma;
-
-                    if ($(this.important)) {
-                        important = true;
-                    }
-
-                    if (elements.length > 0 && ($(';') || peek('}'))) {
-                        return new(tree.mixin.Call)(elements, args, index, env.filename, important);
-                    }
-
-                    restore();
-                },
-
-                //
-                // A Mixin definition, with a list of parameters
-                //
-                //     .rounded (@radius: 2px, @color) {
-                //        ...
-                //     }
-                //
-                // Until we have a finer grained state-machine, we have to
-                // do a look-ahead, to make sure we don't have a mixin call.
-                // See the `rule` function for more information.
-                //
-                // We start by matching `.rounded (`, and then proceed on to
-                // the argument list, which has optional default values.
-                // We store the parameters in `params`, with a `value` key,
-                // if there is a value, such as in the case of `@radius`.
-                //
-                // Once we've got our params list, and a closing `)`, we parse
-                // the `{...}` block.
-                //
-                definition: function () {
-                    var name, params = [], match, ruleset, param, value, cond, variadic = false;
-                    if ((input.charAt(i) !== '.' && input.charAt(i) !== '#') ||
-                        peek(/^[^{]*\}/)) return;
-
-                    save();
-
-                    if (match = $(/^([#.](?:[\w-]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+)\s*\(/)) {
-                        name = match[1];
-
-                        do {
-                            $(this.comment);
-                            if (input.charAt(i) === '.' && $(/^\.{3}/)) {
-                                variadic = true;
-                                params.push({ variadic: true });
-                                break;
-                            } else if (param = $(this.entities.variable) || $(this.entities.literal)
-                                                                         || $(this.entities.keyword)) {
-                                // Variable
-                                if (param instanceof tree.Variable) {
-                                    if ($(':')) {
-                                        value = expect(this.expression, 'expected expression');
-                                        params.push({ name: param.name, value: value });
-                                    } else if ($(/^\.{3}/)) {
-                                        params.push({ name: param.name, variadic: true });
-                                        variadic = true;
-                                        break;
-                                    } else {
-                                        params.push({ name: param.name });
-                                    }
-                                } else {
-                                    params.push({ value: param });
-                                }
-                            } else {
-                                break;
-                            }
-                        } while ($(',') || $(';'))
-
-                        // .mixincall("@{a}");
-                        // looks a bit like a mixin definition.. so we have to be nice and restore
-                        if (!$(')')) {
-                            furthest = i;
-                            restore();
-                        }
-
-                        $(this.comment);
-
-                        if ($(/^when/)) { // Guard
-                            cond = expect(this.conditions, 'expected condition');
-                        }
-
-                        ruleset = $(this.block);
-
-                        if (ruleset) {
-                            return new(tree.mixin.Definition)(name, params, ruleset, cond, variadic);
-                        } else {
-                            restore();
-                        }
-                    }
-                }
-            },
-
-            //
-            // Entities are the smallest recognized token,
-            // and can be found inside a rule's value.
-            //
-            entity: function () {
-                return $(this.entities.literal) || $(this.entities.variable) || $(this.entities.url) ||
-                       $(this.entities.call)    || $(this.entities.keyword)  ||$(this.entities.javascript) ||
-                       $(this.comment);
-            },
-
-            //
-            // A Rule terminator. Note that we use `peek()` to check for '}',
-            // because the `block` rule will be expecting it, but we still need to make sure
-            // it's there, if ';' was ommitted.
-            //
-            end: function () {
-                return $(';') || peek('}');
-            },
-
-            //
-            // IE's alpha function
-            //
-            //     alpha(opacity=88)
-            //
-            alpha: function () {
-                var value;
-
-                if (! $(/^\(opacity=/i)) return;
-                if (value = $(/^\d+/) || $(this.entities.variable)) {
-                    expect(')');
-                    return new(tree.Alpha)(value);
-                }
-            },
-
-            //
-            // A Selector Element
-            //
-            //     div
-            //     + h1
-            //     #socks
-            //     input[type="text"]
-            //
-            // Elements are the building blocks for Selectors,
-            // they are made out of a `Combinator` (see combinator rule),
-            // and an element name, such as a tag a class, or `*`.
-            //
-            element: function () {
-                var e, t, c, v;
-
-                c = $(this.combinator);
-
-                e = $(/^(?:\d+\.\d+|\d+)%/) || $(/^(?:[.#]?|:*)(?:[\w-]|[^\x00-\x9f]|\\(?:[A-Fa-f0-9]{1,6} ?|[^A-Fa-f0-9]))+/) ||
-                    $('*') || $('&') || $(this.attribute) || $(/^\([^()@]+\)/) || $(/^[\.#](?=@)/) || $(this.entities.variableCurly);
-
-                if (! e) {
-                    if ($('(')) {
-                        if ((v = (//$(this.entities.variableCurly) ||
-                                $(this.selector))) &&
-                                $(')')) {
-                            e = new(tree.Paren)(v);
-                        }
-                    }
-                }
-
-                if (e) { return new(tree.Element)(c, e, i) }
-            },
-
-            //
-            // Combinators combine elements together, in a Selector.
-            //
-            // Because our parser isn't white-space sensitive, special care
-            // has to be taken, when parsing the descendant combinator, ` `,
-            // as it's an empty space. We have to check the previous character
-            // in the input, to see if it's a ` ` character. More info on how
-            // we deal with this in *combinator.js*.
-            //
-            combinator: function () {
-                var match, c = input.charAt(i);
-
-                if (c === '>' || c === '+' || c === '~' || c === '|') {
-                    i++;
-                    while (input.charAt(i).match(/\s/)) { i++ }
-                    return new(tree.Combinator)(c);
-                } else if (input.charAt(i - 1).match(/\s/)) {
-                    return new(tree.Combinator)(" ");
-                } else {
-                    return new(tree.Combinator)(null);
-                }
-            },
-
-            //
-            // A CSS Selector
-            //
-            //     .class > div + h1
-            //     li a:hover
-            //
-            // Selectors are made out of one or more Elements, see above.
-            //
-            selector: function () {
-                var sel, e, elements = [], c, match, extend;
-
-                while ((extend = $(this.extend)) || (e = $(this.element))) {
-                    if (!e) {
-                        break;
-                    }
-                    c = input.charAt(i);
-                    elements.push(e)
-                    e = null;
-                    if (c === '{' || c === '}' || c === ';' || c === ',' || c === ')') { break }
-                }
-
-                if (elements.length > 0) { return new(tree.Selector)(elements, extend) }
-                if (extend) { error("Extend must be used to extend a selector"); }
-            },
-            attribute: function () {
-                var attr = '', key, val, op;
-
-                if (! $('[')) return;
-
-                if (key = $(/^(?:[_A-Za-z0-9-]|\\.)+/) || $(this.entities.quoted)) {
-                    if ((op = $(/^[|~*$^]?=/)) &&
-                        (val = $(this.entities.quoted) || $(/^[\w-]+/))) {
-                        attr = [key, op, val.toCSS ? val.toCSS() : val].join('');
-                    } else { attr = key }
-                }
-
-                if (! $(']')) return;
-
-                if (attr) { return "[" + attr + "]" }
-            },
-
-            //
-            // The `block` rule is used by `ruleset` and `mixin.definition`.
-            // It's a wrapper around the `primary` rule, with added `{}`.
-            //
-            block: function () {
-                var content;
-                if ($('{') && (content = $(this.primary)) && $('}')) {
-                    return content;
-                }
-            },
-
-            //
-            // div, .class, body > p {...}
-            //
-            ruleset: function () {
-                var selectors = [], s, rules, match, debugInfo;
-
-                save();
-
-                if (env.dumpLineNumbers)
-                    debugInfo = getDebugInfo(i, input, env);
-
-                while (s = $(this.selector)) {
-                    selectors.push(s);
-                    $(this.comment);
-                    if (! $(',')) { break }
-                    $(this.comment);
-                }
-
-                if (selectors.length > 0 && (rules = $(this.block))) {
-                    var ruleset = new(tree.Ruleset)(selectors, rules, env.strictImports);
-                    if (env.dumpLineNumbers)
-                        ruleset.debugInfo = debugInfo;
-                    return ruleset;
-                } else {
-                    // Backtrack
-                    furthest = i;
-                    restore();
-                }
-            },
-            rule: function () {
-                var name, value, c = input.charAt(i), important, match;
-                save();
-
-                if (c === '.' || c === '#' || c === '&') { return }
-
-                if (name = $(this.variable) || $(this.property)) {
-                    if (!env.compress && (name.charAt(0) != '@') && (match = /^([^@+\/'"*`(;{}-]*);/.exec(chunks[j]))) {
-                        i += match[0].length - 1;
-                        value = new(tree.Anonymous)(match[1]);
-                    } else {
-                        value = $(this.value);
-                    }
-                    important = $(this.important);
-
-                    if (value && $(this.end)) {
-                        return new(tree.Rule)(name, value, important, memo);
-                    } else {
-                        furthest = i;
-                        restore();
-                    }
-                }
-            },
-
-            //
-            // An @import directive
-            //
-            //     @import "lib";
-            //
-            // Depending on our environemnt, importing is done differently:
-            // In the browser, it's an XHR request, in Node, it would be a
-            // file-system operation. The function used for importing is
-            // stored in `import`, which we pass to the Import constructor.
-            //
-            "import": function () {
-                var path, features, index = i;
-
-                save();
-
-                var dir = $(/^@import(?:-(once|multiple))?\s+/);
-
-                if (dir && (path = $(this.entities.quoted) || $(this.entities.url))) {
-                    features = $(this.mediaFeatures);
-                    if ($(';')) {
-                        features = features && new(tree.Value)(features);
-                        var importOnce = dir[1] !== 'multiple';
-                        return new(tree.Import)(path, imports, features, importOnce, index, env.rootpath);
-                    }
-                }
-
-                restore();
-            },
-
-            mediaFeature: function () {
-                var e, p, nodes = [];
-
-                do {
-                    if (e = $(this.entities.keyword)) {
-                        nodes.push(e);
-                    } else if ($('(')) {
-                        p = $(this.property);
-                        e = $(this.value);
-                        if ($(')')) {
-                            if (p && e) {
-                                nodes.push(new(tree.Paren)(new(tree.Rule)(p, e, null, i, true)));
-                            } else if (e) {
-                                nodes.push(new(tree.Paren)(e));
-                            } else {
-                                return null;
-                            }
-                        } else { return null }
-                    }
-                } while (e);
-
-                if (nodes.length > 0) {
-                    return new(tree.Expression)(nodes);
-                }
-            },
-
-            mediaFeatures: function () {
-                var e, features = [];
-
-                do {
-                  if (e = $(this.mediaFeature)) {
-                      features.push(e);
-                      if (! $(',')) { break }
-                  } else if (e = $(this.entities.variable)) {
-                      features.push(e);
-                      if (! $(',')) { break }
-                  }
-                } while (e);
-
-                return features.length > 0 ? features : null;
-            },
-
-            media: function () {
-                var features, rules, media, debugInfo;
-
-                if (env.dumpLineNumbers)
-                    debugInfo = getDebugInfo(i, input, env);
-
-                if ($(/^@media/)) {
-                    features = $(this.mediaFeatures);
-
-                    if (rules = $(this.block)) {
-                        media = new(tree.Media)(rules, features);
-                        if(env.dumpLineNumbers)
-                            media.debugInfo = debugInfo;
-                        return media;
-                    }
-                }
-            },
-
-            //
-            // A CSS Directive
-            //
-            //     @charset "utf-8";
-            //
-            directive: function () {
-                var name, value, rules, identifier, e, nodes, nonVendorSpecificName,
-                    hasBlock, hasIdentifier, hasExpression;
-
-                if (input.charAt(i) !== '@') return;
-
-                if (value = $(this['import']) || $(this.media)) {
-                    return value;
-                }
-
-                save();
-
-                name = $(/^@[a-z-]+/);
-
-                if (!name) return;
-
-                nonVendorSpecificName = name;
-                if (name.charAt(1) == '-' && name.indexOf('-', 2) > 0) {
-                    nonVendorSpecificName = "@" + name.slice(name.indexOf('-', 2) + 1);
-                }
-
-                switch(nonVendorSpecificName) {
-                    case "@font-face":
-                        hasBlock = true;
-                        break;
-                    case "@viewport":
-                    case "@top-left":
-                    case "@top-left-corner":
-                    case "@top-center":
-                    case "@top-right":
-                    case "@top-right-corner":
-                    case "@bottom-left":
-                    case "@bottom-left-corner":
-                    case "@bottom-center":
-                    case "@bottom-right":
-                    case "@bottom-right-corner":
-                    case "@left-top":
-                    case "@left-middle":
-                    case "@left-bottom":
-                    case "@right-top":
-                    case "@right-middle":
-                    case "@right-bottom":
-                        hasBlock = true;
-                        break;
-                    case "@page":
-                    case "@document":
-                    case "@supports":
-                    case "@keyframes":
-                        hasBlock = true;
-                        hasIdentifier = true;
-                        break;
-                    case "@namespace":
-                        hasExpression = true;
-                        break;
-                }
-
-                if (hasIdentifier) {
-                    name += " " + ($(/^[^{]+/) || '').trim();
-                }
-
-                if (hasBlock)
-                {
-                    if (rules = $(this.block)) {
-                        return new(tree.Directive)(name, rules);
-                    }
-                } else {
-                    if ((value = hasExpression ? $(this.expression) : $(this.entity)) && $(';')) {
-                        var directive = new(tree.Directive)(name, value);
-                        if (env.dumpLineNumbers) {
-                            directive.debugInfo = getDebugInfo(i, input, env);
-                        }
-                        return directive;
-                    }
-                }
-
-                restore();
-            },
-
-            //
-            // A Value is a comma-delimited list of Expressions
-            //
-            //     font-family: Baskerville, Georgia, serif;
-            //
-            // In a Rule, a Value represents everything after the `:`,
-            // and before the `;`.
-            //
-            value: function () {
-                var e, expressions = [], important;
-
-                while (e = $(this.expression)) {
-                    expressions.push(e);
-                    if (! $(',')) { break }
-                }
-
-                if (expressions.length > 0) {
-                    return new(tree.Value)(expressions);
-                }
-            },
-            important: function () {
-                if (input.charAt(i) === '!') {
-                    return $(/^! *important/);
-                }
-            },
-            sub: function () {
-                var a, e;
-
-                if ($('(')) {
-                    if (a = $(this.addition)) {
-                        e = new(tree.Expression)([a]);
-                        expect(')');
-                        e.parens = true;
-                        return e;
-                    }
-                }
-            },
-            multiplication: function () {
-                var m, a, op, operation, isSpaced, expression = [];
-                if (m = $(this.operand)) {
-                    isSpaced = isWhitespace(input.charAt(i - 1));
-                    while (!peek(/^\/[*\/]/) && (op = ($('/') || $('*')))) {
-                        if (a = $(this.operand)) {
-                            m.parensInOp = true;
-                            a.parensInOp = true;
-                            operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
-                            isSpaced = isWhitespace(input.charAt(i - 1));
-                        } else {
-                            break;
-                        }
-                    }
-                    return operation || m;
-                }
-            },
-            addition: function () {
-                var m, a, op, operation, isSpaced;
-                if (m = $(this.multiplication)) {
-                    isSpaced = isWhitespace(input.charAt(i - 1));
-                    while ((op = $(/^[-+]\s+/) || (!isSpaced && ($('+') || $('-')))) &&
-                           (a = $(this.multiplication))) {
-                        m.parensInOp = true;
-                        a.parensInOp = true;
-                        operation = new(tree.Operation)(op, [operation || m, a], isSpaced);
-                        isSpaced = isWhitespace(input.charAt(i - 1));
-                    }
-                    return operation || m;
-                }
-            },
-            conditions: function () {
-                var a, b, index = i, condition;
-
-                if (a = $(this.condition)) {
-                    while ($(',') && (b = $(this.condition))) {
-                        condition = new(tree.Condition)('or', condition || a, b, index);
-                    }
-                    return condition || a;
-                }
-            },
-            condition: function () {
-                var a, b, c, op, index = i, negate = false;
-
-                if ($(/^not/)) { negate = true }
-                expect('(');
-                if (a = $(this.addition) || $(this.entities.keyword) || $(this.entities.quoted)) {
-                    if (op = $(/^(?:>=|=<|[<=>])/)) {
-                        if (b = $(this.addition) || $(this.entities.keyword) || $(this.entities.quoted)) {
-                            c = new(tree.Condition)(op, a, b, index, negate);
-                        } else {
-                            error('expected expression');
-                        }
-                    } else {
-                        c = new(tree.Condition)('=', a, new(tree.Keyword)('true'), index, negate);
-                    }
-                    expect(')');
-                    return $(/^and/) ? new(tree.Condition)('and', c, $(this.condition)) : c;
-                }
-            },
-
-            //
-            // An operand is anything that can be part of an operation,
-            // such as a Color, or a Variable
-            //
-            operand: function () {
-                var negate, p = input.charAt(i + 1);
-
-                if (input.charAt(i) === '-' && (p === '@' || p === '(')) { negate = $('-') }
-                var o = $(this.sub) || $(this.entities.dimension) ||
-                        $(this.entities.color) || $(this.entities.variable) ||
-                        $(this.entities.call);
-
-                if (negate) {
-                    o.parensInOp = true;
-                    o = new(tree.Negative)(o);
-                }
-
-                return o;
-            },
-
-            //
-            // Expressions either represent mathematical operations,
-            // or white-space delimited Entities.
-            //
-            //     1px solid black
-            //     @var * 2
-            //
-            expression: function () {
-                var e, delim, entities = [], d;
-
-                while (e = $(this.addition) || $(this.entity)) {
-                    entities.push(e);
-                    // operations do not allow keyword "/" dimension (e.g. small/20px) so we support that here
-                    if (!peek(/^\/[\/*]/) && (delim = $('/'))) {
-                        entities.push(new(tree.Anonymous)(delim));
-                    }
-                }
-                if (entities.length > 0) {
-                    return new(tree.Expression)(entities);
-                }
-            },
-            property: function () {
-                var name;
-
-                if (name = $(/^(\*?-?[_a-z0-9-]+)\s*:/)) {
-                    return name[1];
-                }
-            }
-        }
-    };
-};
-
-if (less.mode === 'browser' || less.mode === 'rhino') {
-    //
-    // Used by `@import` directives
-    //
-    less.Parser.importer = function (path, paths, callback, env) {
-        if (!/^([a-z-]+:)?\//.test(path) && paths.length > 0) {
-            path = paths[0] + path;
-        }
-        // We pass `true` as 3rd argument, to force the reload of the import.
-        // This is so we can get the syntax tree as opposed to just the CSS output,
-        // as we need this to evaluate the current stylesheet.
-        loadStyleSheet(env.toSheet(path),
-            function (e, root, data, sheet, _, path) {
-                callback.call(null, e, root, path);
-            }, true);
-    };
-}
-
-(function (tree) {
-
-tree.functions = {
-    rgb: function (r, g, b) {
-        return this.rgba(r, g, b, 1.0);
-    },
-    rgba: function (r, g, b, a) {
-        var rgb = [r, g, b].map(function (c) { return scaled(c, 256); });
-        a = number(a);
-        return new(tree.Color)(rgb, a);
-    },
-    hsl: function (h, s, l) {
-        return this.hsla(h, s, l, 1.0);
-    },
-    hsla: function (h, s, l, a) {
-        h = (number(h) % 360) / 360;
-        s = number(s); l = number(l); a = number(a);
-
-        var m2 = l <= 0.5 ? l * (s + 1) : l + s - l * s;
-        var m1 = l * 2 - m2;
-
-        return this.rgba(hue(h + 1/3) * 255,
-                         hue(h)       * 255,
-                         hue(h - 1/3) * 255,
-                         a);
-
-        function hue(h) {
-            h = h < 0 ? h + 1 : (h > 1 ? h - 1 : h);
-            if      (h * 6 < 1) return m1 + (m2 - m1) * h * 6;
-            else if (h * 2 < 1) return m2;
-            else if (h * 3 < 2) return m1 + (m2 - m1) * (2/3 - h) * 6;
-            else                return m1;
-        }
-    },
-
-    hsv: function(h, s, v) {
-        return this.hsva(h, s, v, 1.0);
-    },
-
-    hsva: function(h, s, v, a) {
-        h = ((number(h) % 360) / 360) * 360;
-        s = number(s); v = number(v); a = number(a);
-
-        var i, f;
-        i = Math.floor((h / 60) % 6);
-        f = (h / 60) - i;
-
-        var vs = [v,
-                  v * (1 - s),
-                  v * (1 - f * s),
-                  v * (1 - (1 - f) * s)];
-        var perm = [[0, 3, 1],
-                    [2, 0, 1],
-                    [1, 0, 3],
-                    [1, 2, 0],
-                    [3, 1, 0],
-                    [0, 1, 2]];
-
-        return this.rgba(vs[perm[i][0]] * 255,
-                         vs[perm[i][1]] * 255,
-                         vs[perm[i][2]] * 255,
-                         a);
-    },
-
-    hue: function (color) {
-        return new(tree.Dimension)(Math.round(color.toHSL().h));
-    },
-    saturation: function (color) {
-        return new(tree.Dimension)(Math.round(color.toHSL().s * 100), '%');
-    },
-    lightness: function (color) {
-        return new(tree.Dimension)(Math.round(color.toHSL().l * 100), '%');
-    },
-    hsvhue: function(color) {
-        return new(tree.Dimension)(Math.round(color.toHSV().h));
-    },
-    hsvsaturation: function (color) {
-        return new(tree.Dimension)(Math.round(color.toHSV().s * 100), '%');
-    },
-    hsvvalue: function (color) {
-        return new(tree.Dimension)(Math.round(color.toHSV().v * 100), '%');
-    },
-    red: function (color) {
-        return new(tree.Dimension)(color.rgb[0]);
-    },
-    green: function (color) {
-        return new(tree.Dimension)(color.rgb[1]);
-    },
-    blue: function (color) {
-        return new(tree.Dimension)(color.rgb[2]);
-    },
-    alpha: function (color) {
-        return new(tree.Dimension)(color.toHSL().a);
-    },
-    luma: function (color) {
-        return new(tree.Dimension)(Math.round(color.luma() * color.alpha * 100), '%');
-    },
-    saturate: function (color, amount) {
-        var hsl = color.toHSL();
-
-        hsl.s += amount.value / 100;
-        hsl.s = clamp(hsl.s);
-        return hsla(hsl);
-    },
-    desaturate: function (color, amount) {
-        var hsl = color.toHSL();
-
-        hsl.s -= amount.value / 100;
-        hsl.s = clamp(hsl.s);
-        return hsla(hsl);
-    },
-    lighten: function (color, amount) {
-        var hsl = color.toHSL();
-
-        hsl.l += amount.value / 100;
-        hsl.l = clamp(hsl.l);
-        return hsla(hsl);
-    },
-    darken: function (color, amount) {
-        var hsl = color.toHSL();
-
-        hsl.l -= amount.value / 100;
-        hsl.l = clamp(hsl.l);
-        return hsla(hsl);
-    },
-    fadein: function (color, amount) {
-        var hsl = color.toHSL();
-
-        hsl.a += amount.value / 100;
-        hsl.a = clamp(hsl.a);
-        return hsla(hsl);
-    },
-    fadeout: function (color, amount) {
-        var hsl = color.toHSL();
-
-        hsl.a -= amount.value / 100;
-        hsl.a = clamp(hsl.a);
-        return hsla(hsl);
-    },
-    fade: function (color, amount) {
-        var hsl = color.toHSL();
-
-        hsl.a = amount.value / 100;
-        hsl.a = clamp(hsl.a);
-        return hsla(hsl);
-    },
-    spin: function (color, amount) {
-        var hsl = color.toHSL();
-        var hue = (hsl.h + amount.value) % 360;
-
-        hsl.h = hue < 0 ? 360 + hue : hue;
-
-        return hsla(hsl);
-    },
-    //
-    // Copyright (c) 2006-2009 Hampton Catlin, Nathan Weizenbaum, and Chris Eppstein
-    // http://sass-lang.com
-    //
-    mix: function (color1, color2, weight) {
-        if (!weight) {
-            weight = new(tree.Dimension)(50);
-        }
-        var p = weight.value / 100.0;
-        var w = p * 2 - 1;
-        var a = color1.toHSL().a - color2.toHSL().a;
-
-        var w1 = (((w * a == -1) ? w : (w + a) / (1 + w * a)) + 1) / 2.0;
-        var w2 = 1 - w1;
-
-        var rgb = [color1.rgb[0] * w1 + color2.rgb[0] * w2,
-                   color1.rgb[1] * w1 + color2.rgb[1] * w2,
-                   color1.rgb[2] * w1 + color2.rgb[2] * w2];
-
-        var alpha = color1.alpha * p + color2.alpha * (1 - p);
-
-        return new(tree.Color)(rgb, alpha);
-    },
-    greyscale: function (color) {
-        return this.desaturate(color, new(tree.Dimension)(100));
-    },
-    contrast: function (color, dark, light, threshold) {
-        // filter: contrast(3.2);
-        // should be kept as is, so check for color
-        if (!color.rgb) {
-            return null;
-        }
-        if (typeof light === 'undefined') {
-            light = this.rgba(255, 255, 255, 1.0);
-        }
-        if (typeof dark === 'undefined') {
-            dark = this.rgba(0, 0, 0, 1.0);
-        }
-        //Figure out which is actually light and dark!
-        if (dark.luma() > light.luma()) {
-            var t = light;
-            light = dark;
-            dark = t;
-        }
-        if (typeof threshold === 'undefined') {
-            threshold = 0.43;
-        } else {
-            threshold = number(threshold);
-        }
-        if ((color.luma() * color.alpha) < threshold) {
-            return light;
-        } else {
-            return dark;
-        }
-    },
-    e: function (str) {
-        return new(tree.Anonymous)(str instanceof tree.JavaScript ? str.evaluated : str);
-    },
-    escape: function (str) {
-        return new(tree.Anonymous)(encodeURI(str.value).replace(/=/g, "%3D").replace(/:/g, "%3A").replace(/#/g, "%23").replace(/;/g, "%3B").replace(/\(/g, "%28").replace(/\)/g, "%29"));
-    },
-    '%': function (quoted /* arg, arg, ...*/) {
-        var args = Array.prototype.slice.call(arguments, 1),
-            str = quoted.value;
-
-        for (var i = 0; i < args.length; i++) {
-            str = str.replace(/%[sda]/i, function(token) {
-                var value = token.match(/s/i) ? args[i].value : args[i].toCSS();
-                return token.match(/[A-Z]$/) ? encodeURIComponent(value) : value;
-            });
-        }
-        str = str.replace(/%%/g, '%');
-        return new(tree.Quoted)('"' + str + '"', str);
-    },
-    unit: function (val, unit) {
-        return new(tree.Dimension)(val.value, unit ? unit.toCSS() : "");
-    },
-    convert: function (val, unit) {
-        return val.convertTo(unit.value);
-    },
-    round: function (n, f) {
-        var fraction = typeof(f) === "undefined" ? 0 : f.value;
-        return this._math(function(num) { return num.toFixed(fraction); }, null, n);
-    },
-    pi: function () {
-        return new(tree.Dimension)(Math.PI);
-    },
-    mod: function(a, b) {
-        return new(tree.Dimension)(a.value % b.value, a.unit);
-    },
-    pow: function(x, y) {
-        if (typeof x === "number" && typeof y === "number") {
-            x = new(tree.Dimension)(x);
-            y = new(tree.Dimension)(y);
-        } else if (!(x instanceof tree.Dimension) || !(y instanceof tree.Dimension)) {
-            throw { type: "Argument", message: "arguments must be numbers" };
-        }
-
-        return new(tree.Dimension)(Math.pow(x.value, y.value), x.unit);
-    },
-    _math: function (fn, unit, n) {
-        if (n instanceof tree.Dimension) {
-            return new(tree.Dimension)(fn(parseFloat(n.value)), unit == null ? n.unit : unit);
-        } else if (typeof(n) === 'number') {
-            return fn(n);
-        } else {
-            throw { type: "Argument", message: "argument must be a number" };
-        }
-    },
-    argb: function (color) {
-        return new(tree.Anonymous)(color.toARGB());
-
-    },
-    percentage: function (n) {
-        return new(tree.Dimension)(n.value * 100, '%');
-    },
-    color: function (n) {
-        if (n instanceof tree.Quoted) {
-            return new(tree.Color)(n.value.slice(1));
-        } else {
-            throw { type: "Argument", message: "argument must be a string" };
-        }
-    },
-    iscolor: function (n) {
-        return this._isa(n, tree.Color);
-    },
-    isnumber: function (n) {
-        return this._isa(n, tree.Dimension);
-    },
-    isstring: function (n) {
-        return this._isa(n, tree.Quoted);
-    },
-    iskeyword: function (n) {
-        return this._isa(n, tree.Keyword);
-    },
-    isurl: function (n) {
-        return this._isa(n, tree.URL);
-    },
-    ispixel: function (n) {
-        return (n instanceof tree.Dimension) && n.unit.is('px') ? tree.True : tree.False;
-    },
-    ispercentage: function (n) {
-        return (n instanceof tree.Dimension) && n.unit.is('%') ? tree.True : tree.False;
-    },
-    isem: function (n) {
-        return (n instanceof tree.Dimension) && n.unit.is('em') ? tree.True : tree.False;
-    },
-    _isa: function (n, Type) {
-        return (n instanceof Type) ? tree.True : tree.False;
-    },
-
-    /* Blending modes */
-
-    multiply: function(color1, color2) {
-        var r = color1.rgb[0] * color2.rgb[0] / 255;
-        var g = color1.rgb[1] * color2.rgb[1] / 255;
-        var b = color1.rgb[2] * color2.rgb[2] / 255;
-        return this.rgb(r, g, b);
-    },
-    screen: function(color1, color2) {
-        var r = 255 - (255 - color1.rgb[0]) * (255 - color2.rgb[0]) / 255;
-        var g = 255 - (255 - color1.rgb[1]) * (255 - color2.rgb[1]) / 255;
-        var b = 255 - (255 - color1.rgb[2]) * (255 - color2.rgb[2]) / 255;
-        return this.rgb(r, g, b);
-    },
-    overlay: function(color1, color2) {
-        var r = color1.rgb[0] < 128 ? 2 * color1.rgb[0] * color2.rgb[0] / 255 : 255 - 2 * (255 - color1.rgb[0]) * (255 - color2.rgb[0]) / 255;
-        var g = color1.rgb[1] < 128 ? 2 * color1.rgb[1] * color2.rgb[1] / 255 : 255 - 2 * (255 - color1.rgb[1]) * (255 - color2.rgb[1]) / 255;
-        var b = color1.rgb[2] < 128 ? 2 * color1.rgb[2] * color2.rgb[2] / 255 : 255 - 2 * (255 - color1.rgb[2]) * (255 - color2.rgb[2]) / 255;
-        return this.rgb(r, g, b);
-    },
-    softlight: function(color1, color2) {
-        var t = color2.rgb[0] * color1.rgb[0] / 255;
-        var r = t + color1.rgb[0] * (255 - (255 - color1.rgb[0]) * (255 - color2.rgb[0]) / 255 - t) / 255;
-        t = color2.rgb[1] * color1.rgb[1] / 255;
-        var g = t + color1.rgb[1] * (255 - (255 - color1.rgb[1]) * (255 - color2.rgb[1]) / 255 - t) / 255;
-        t = color2.rgb[2] * color1.rgb[2] / 255;
-        var b = t + color1.rgb[2] * (255 - (255 - color1.rgb[2]) * (255 - color2.rgb[2]) / 255 - t) / 255;
-        return this.rgb(r, g, b);
-    },
-    hardlight: function(color1, color2) {
-        var r = color2.rgb[0] < 128 ? 2 * color2.rgb[0] * color1.rgb[0] / 255 : 255 - 2 * (255 - color2.rgb[0]) * (255 - color1.rgb[0]) / 255;
-        var g = color2.rgb[1] < 128 ? 2 * color2.rgb[1] * color1.rgb[1] / 255 : 255 - 2 * (255 - color2.rgb[1]) * (255 - color1.rgb[1]) / 255;
-        var b = color2.rgb[2] < 128 ? 2 * color2.rgb[2] * color1.rgb[2] / 255 : 255 - 2 * (255 - color2.rgb[2]) * (255 - color1.rgb[2]) / 255;
-        return this.rgb(r, g, b);
-    },
-    difference: function(color1, color2) {
-        var r = Math.abs(color1.rgb[0] - color2.rgb[0]);
-        var g = Math.abs(color1.rgb[1] - color2.rgb[1]);
-        var b = Math.abs(color1.rgb[2] - color2.rgb[2]);
-        return this.rgb(r, g, b);
-    },
-    exclusion: function(color1, color2) {
-        var r = color1.rgb[0] + color2.rgb[0] * (255 - color1.rgb[0] - color1.rgb[0]) / 255;
-        var g = color1.rgb[1] + color2.rgb[1] * (255 - color1.rgb[1] - color1.rgb[1]) / 255;
-        var b = color1.rgb[2] + color2.rgb[2] * (255 - color1.rgb[2] - color1.rgb[2]) / 255;
-        return this.rgb(r, g, b);
-    },
-    average: function(color1, color2) {
-        var r = (color1.rgb[0] + color2.rgb[0]) / 2;
-        var g = (color1.rgb[1] + color2.rgb[1]) / 2;
-        var b = (color1.rgb[2] + color2.rgb[2]) / 2;
-        return this.rgb(r, g, b);
-    },
-    negation: function(color1, color2) {
-        var r = 255 - Math.abs(255 - color2.rgb[0] - color1.rgb[0]);
-        var g = 255 - Math.abs(255 - color2.rgb[1] - color1.rgb[1]);
-        var b = 255 - Math.abs(255 - color2.rgb[2] - color1.rgb[2]);
-        return this.rgb(r, g, b);
-    },
-    tint: function(color, amount) {
-        return this.mix(this.rgb(255,255,255), color, amount);
-    },
-    shade: function(color, amount) {
-        return this.mix(this.rgb(0, 0, 0), color, amount);
-    },
-    extract: function(values, index) {
-        index = index.value - 1; // (1-based index)
-        return values.value[index];
-    },
-
-    "data-uri": function(mimetypeNode, filePathNode) {
-
-        if (typeof window !== 'undefined') {
-            return new tree.URL(filePathNode || mimetypeNode, this.rootpath).eval(this.env);
-        }
-
-        var mimetype = mimetypeNode.value;
-        var filePath = (filePathNode && filePathNode.value);
-
-        var fs = require("fs"),
-            path = require("path"),
-            useBase64 = false;
-
-        if (arguments.length < 2) {
-            filePath = mimetype;
-        }
-
-        if (this.currentDirectory && this.env.isPathRelative(filePath)) {
-            filePath = path.join(this.currentDirectory, filePath);
-        }
-
-        // detect the mimetype if not given
-        if (arguments.length < 2) {
-            var mime;
-            try {
-                mime = require('mime');
-            } catch (ex) {
-                mime = tree._mime;
-            }
-
-            mimetype = mime.lookup(filePath);
-
-            // use base 64 unless it's an ASCII or UTF-8 format
-            var charset = mime.charsets.lookup(mimetype);
-            useBase64 = ['US-ASCII', 'UTF-8'].indexOf(charset) < 0;
-            if (useBase64) mimetype += ';base64';
-        }
-        else {
-            useBase64 = /;base64$/.test(mimetype)
-        }
-
-        var buf = fs.readFileSync(filePath);
-
-        // IE8 cannot handle a data-uri larger than 32KB. If this is exceeded
-        // and the --ieCompat flag is enabled, return a normal url() instead.
-        var DATA_URI_MAX_KB = 32,
-            fileSizeInKB = parseInt((buf.length / 1024), 10);
-        if (fileSizeInKB >= DATA_URI_MAX_KB) {
-            // the url() must be relative, not an absolute file path
-            filePath = path.relative(this.currentDirectory, filePath);
-
-            if (this.env.ieCompat !== false) {
-                if (!this.env.silent) {
-                    console.warn("Skipped data-uri embedding of %s because its size (%dKB) exceeds IE8-safe %dKB!", filePath, fileSizeInKB, DATA_URI_MAX_KB);
-                }
-
-                return new tree.URL(filePathNode || mimetypeNode, this.rootpath).eval(this.env);
-            } else if (!this.env.silent) {
-                // if explicitly disabled (via --no-ie-compat on CLI, or env.ieCompat === false), merely warn
-                console.warn("WARNING: Embedding %s (%dKB) exceeds IE8's data-uri size limit of %dKB!", filePath, fileSizeInKB, DATA_URI_MAX_KB);
-            }
-        }
-
-        buf = useBase64 ? buf.toString('base64')
-                        : encodeURIComponent(buf);
-
-        var uri = "'data:" + mimetype + ',' + buf + "'";
-        return new(tree.URL)(new(tree.Anonymous)(uri));
-    }
-};
-
-// these static methods are used as a fallback when the optional 'mime' dependency is missing
-tree._mime = {
-    // this map is intentionally incomplete
-    // if you want more, install 'mime' dep
-    _types: {
-        '.htm' : 'text/html',
-        '.html': 'text/html',
-        '.gif' : 'image/gif',
-        '.jpg' : 'image/jpeg',
-        '.jpeg': 'image/jpeg',
-        '.png' : 'image/png'
-    },
-    lookup: function (filepath) {
-        var ext = require('path').extname(filepath),
-            type = tree._mime._types[ext];
-        if (type === undefined) {
-            throw new Error('Optional dependency "mime" is required for ' + ext);
-        }
-        return type;
-    },
-    charsets: {
-        lookup: function (type) {
-            // assumes all text types are UTF-8
-            return type && (/^text\//).test(type) ? 'UTF-8' : '';
-        }
-    }
-};
-
-var mathFunctions = [{name:"ceil"}, {name:"floor"}, {name: "sqrt"}, {name:"abs"},
-        {name:"tan", unit: ""}, {name:"sin", unit: ""}, {name:"cos", unit: ""},
-        {name:"atan", unit: "rad"}, {name:"asin", unit: "rad"}, {name:"acos", unit: "rad"}],
-    createMathFunction = function(name, unit) {
-        return function(n) {
-            if (unit != null) {
-                n = n.unify();
-            }
-            return this._math(Math[name], unit, n);
-        };
-    };
-
-for(var i = 0; i < mathFunctions.length; i++) {
-    tree.functions[mathFunctions[i].name] = createMathFunction(mathFunctions[i].name, mathFunctions[i].unit);
-}
-
-function hsla(color) {
-    return tree.functions.hsla(color.h, color.s, color.l, color.a);
-}
-
-function scaled(n, size) {
-    if (n instanceof tree.Dimension && n.unit.is('%')) {
-        return parseFloat(n.value * size / 100);
-    } else {
-        return number(n);
-    }
-}
-
-function number(n) {
-    if (n instanceof tree.Dimension) {
-        return parseFloat(n.unit.is('%') ? n.value / 100 : n.value);
-    } else if (typeof(n) === 'number') {
-        return n;
-    } else {
-        throw {
-            error: "RuntimeError",
-            message: "color functions take numbers as parameters"
-        };
-    }
-}
-
-function clamp(val) {
-    return Math.min(1, Math.max(0, val));
-}
-
-tree.functionCall = function(env, rootpath, currentDirectory) {
-    this.env = env;
-    this.rootpath = rootpath;
-    this.currentDirectory = currentDirectory;
-};
-
-tree.functionCall.prototype = tree.functions;
-
-})(require('./tree'));
-(function (tree) {
-    tree.colors = {
-        'aliceblue':'#f0f8ff',
-        'antiquewhite':'#faebd7',
-        'aqua':'#00ffff',
-        'aquamarine':'#7fffd4',
-        'azure':'#f0ffff',
-        'beige':'#f5f5dc',
-        'bisque':'#ffe4c4',
-        'black':'#000000',
-        'blanchedalmond':'#ffebcd',
-        'blue':'#0000ff',
-        'blueviolet':'#8a2be2',
-        'brown':'#a52a2a',
-        'burlywood':'#deb887',
-        'cadetblue':'#5f9ea0',
-        'chartreuse':'#7fff00',
-        'chocolate':'#d2691e',
-        'coral':'#ff7f50',
-        'cornflowerblue':'#6495ed',
-        'cornsilk':'#fff8dc',
-        'crimson':'#dc143c',
-        'cyan':'#00ffff',
-        'darkblue':'#00008b',
-        'darkcyan':'#008b8b',
-        'darkgoldenrod':'#b8860b',
-        'darkgray':'#a9a9a9',
-        'darkgrey':'#a9a9a9',
-        'darkgreen':'#006400',
-        'darkkhaki':'#bdb76b',
-        'darkmagenta':'#8b008b',
-        'darkolivegreen':'#556b2f',
-        'darkorange':'#ff8c00',
-        'darkorchid':'#9932cc',
-        'darkred':'#8b0000',
-        'darksalmon':'#e9967a',
-        'darkseagreen':'#8fbc8f',
-        'darkslateblue':'#483d8b',
-        'darkslategray':'#2f4f4f',
-        'darkslategrey':'#2f4f4f',
-        'darkturquoise':'#00ced1',
-        'darkviolet':'#9400d3',
-        'deeppink':'#ff1493',
-        'deepskyblue':'#00bfff',
-        'dimgray':'#696969',
-        'dimgrey':'#696969',
-        'dodgerblue':'#1e90ff',
-        'firebrick':'#b22222',
-        'floralwhite':'#fffaf0',
-        'forestgreen':'#228b22',
-        'fuchsia':'#ff00ff',
-        'gainsboro':'#dcdcdc',
-        'ghostwhite':'#f8f8ff',
-        'gold':'#ffd700',
-        'goldenrod':'#daa520',
-        'gray':'#808080',
-        'grey':'#808080',
-        'green':'#008000',
-        'greenyellow':'#adff2f',
-        'honeydew':'#f0fff0',
-        'hotpink':'#ff69b4',
-        'indianred':'#cd5c5c',
-        'indigo':'#4b0082',
-        'ivory':'#fffff0',
-        'khaki':'#f0e68c',
-        'lavender':'#e6e6fa',
-        'lavenderblush':'#fff0f5',
-        'lawngreen':'#7cfc00',
-        'lemonchiffon':'#fffacd',
-        'lightblue':'#add8e6',
-        'lightcoral':'#f08080',
-        'lightcyan':'#e0ffff',
-        'lightgoldenrodyellow':'#fafad2',
-        'lightgray':'#d3d3d3',
-        'lightgrey':'#d3d3d3',
-        'lightgreen':'#90ee90',
-        'lightpink':'#ffb6c1',
-        'lightsalmon':'#ffa07a',
-        'lightseagreen':'#20b2aa',
-        'lightskyblue':'#87cefa',
-        'lightslategray':'#778899',
-        'lightslategrey':'#778899',
-        'lightsteelblue':'#b0c4de',
-        'lightyellow':'#ffffe0',
-        'lime':'#00ff00',
-        'limegreen':'#32cd32',
-        'linen':'#faf0e6',
-        'magenta':'#ff00ff',
-        'maroon':'#800000',
-        'mediumaquamarine':'#66cdaa',
-        'mediumblue':'#0000cd',
-        'mediumorchid':'#ba55d3',
-        'mediumpurple':'#9370d8',
-        'mediumseagreen':'#3cb371',
-        'mediumslateblue':'#7b68ee',
-        'mediumspringgreen':'#00fa9a',
-        'mediumturquoise':'#48d1cc',
-        'mediumvioletred':'#c71585',
-        'midnightblue':'#191970',
-        'mintcream':'#f5fffa',
-        'mistyrose':'#ffe4e1',
-        'moccasin':'#ffe4b5',
-        'navajowhite':'#ffdead',
-        'navy':'#000080',
-        'oldlace':'#fdf5e6',
-        'olive':'#808000',
-        'olivedrab':'#6b8e23',
-        'orange':'#ffa500',
-        'orangered':'#ff4500',
-        'orchid':'#da70d6',
-        'palegoldenrod':'#eee8aa',
-        'palegreen':'#98fb98',
-        'paleturquoise':'#afeeee',
-        'palevioletred':'#d87093',
-        'papayawhip':'#ffefd5',
-        'peachpuff':'#ffdab9',
-        'peru':'#cd853f',
-        'pink':'#ffc0cb',
-        'plum':'#dda0dd',
-        'powderblue':'#b0e0e6',
-        'purple':'#800080',
-        'red':'#ff0000',
-        'rosybrown':'#bc8f8f',
-        'royalblue':'#4169e1',
-        'saddlebrown':'#8b4513',
-        'salmon':'#fa8072',
-        'sandybrown':'#f4a460',
-        'seagreen':'#2e8b57',
-        'seashell':'#fff5ee',
-        'sienna':'#a0522d',
-        'silver':'#c0c0c0',
-        'skyblue':'#87ceeb',
-        'slateblue':'#6a5acd',
-        'slategray':'#708090',
-        'slategrey':'#708090',
-        'snow':'#fffafa',
-        'springgreen':'#00ff7f',
-        'steelblue':'#4682b4',
-        'tan':'#d2b48c',
-        'teal':'#008080',
-        'thistle':'#d8bfd8',
-        'tomato':'#ff6347',
-        // 'transparent':'rgba(0,0,0,0)',
-        'turquoise':'#40e0d0',
-        'violet':'#ee82ee',
-        'wheat':'#f5deb3',
-        'white':'#ffffff',
-        'whitesmoke':'#f5f5f5',
-        'yellow':'#ffff00',
-        'yellowgreen':'#9acd32'
-    };
-})(require('./tree'));
-(function (tree) {
-
-tree.Alpha = function (val) {
-    this.value = val;
-};
-tree.Alpha.prototype = {
-    toCSS: function () {
-        return "alpha(opacity=" +
-               (this.value.toCSS ? this.value.toCSS() : this.value) + ")";
-    },
-    eval: function (env) {
-        if (this.value.eval) { this.value = this.value.eval(env) }
-        return this;
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Anonymous = function (string) {
-    this.value = string.value || string;
-};
-tree.Anonymous.prototype = {
-    toCSS: function () {
-        return this.value;
-    },
-    eval: function () { return this },
-    compare: function (x) {
-        if (!x.toCSS) {
-            return -1;
-        }
-
-        var left = this.toCSS(),
-            right = x.toCSS();
-
-        if (left === right) {
-            return 0;
-        }
-
-        return left < right ? -1 : 1;
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Assignment = function (key, val) {
-    this.key = key;
-    this.value = val;
-};
-tree.Assignment.prototype = {
-    toCSS: function () {
-        return this.key + '=' + (this.value.toCSS ? this.value.toCSS() : this.value);
-    },
-    eval: function (env) {
-        if (this.value.eval) {
-            return new(tree.Assignment)(this.key, this.value.eval(env));
-        }
-        return this;
-    }
-};
-
-})(require('../tree'));(function (tree) {
-
-//
-// A function call node.
-//
-tree.Call = function (name, args, index, filename, rootpath, currentDirectory) {
-    this.name = name;
-    this.args = args;
-    this.index = index;
-    this.filename = filename;
-    this.rootpath = rootpath;
-    this.currentDirectory = currentDirectory;
-};
-tree.Call.prototype = {
-    //
-    // When evaluating a function call,
-    // we either find the function in `tree.functions` [1],
-    // in which case we call it, passing the  evaluated arguments,
-    // if this returns null or we cannot find the function, we
-    // simply print it out as it appeared originally [2].
-    //
-    // The *functions.js* file contains the built-in functions.
-    //
-    // The reason why we evaluate the arguments, is in the case where
-    // we try to pass a variable to a function, like: `saturate(@color)`.
-    // The function should receive the value, not the variable.
-    //
-    eval: function (env) {
-        var args = this.args.map(function (a) { return a.eval(env); }),
-            nameLC = this.name.toLowerCase(),
-            result, func;
-
-        if (nameLC in tree.functions) { // 1.
-            try {
-                func = new tree.functionCall(env, this.rootpath, this.currentDirectory);
-                result = func[nameLC].apply(func, args);
-                if (result != null) {
-                    return result;
-                }
-            } catch (e) {
-                throw { type: e.type || "Runtime",
-                        message: "error evaluating function `" + this.name + "`" +
-                                 (e.message ? ': ' + e.message : ''),
-                        index: this.index, filename: this.filename };
-            }
-        }
-
-        // 2.
-        return new(tree.Anonymous)(this.name +
-            "(" + args.map(function (a) { return a.toCSS(env); }).join(', ') + ")");
-    },
-
-    toCSS: function (env) {
-        return this.eval(env).toCSS();
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-//
-// RGB Colors - #ff0014, #eee
-//
-tree.Color = function (rgb, a) {
-    //
-    // The end goal here, is to parse the arguments
-    // into an integer triplet, such as `128, 255, 0`
-    //
-    // This facilitates operations and conversions.
-    //
-    if (Array.isArray(rgb)) {
-        this.rgb = rgb;
-    } else if (rgb.length == 6) {
-        this.rgb = rgb.match(/.{2}/g).map(function (c) {
-            return parseInt(c, 16);
-        });
-    } else {
-        this.rgb = rgb.split('').map(function (c) {
-            return parseInt(c + c, 16);
-        });
-    }
-    this.alpha = typeof(a) === 'number' ? a : 1;
-};
-tree.Color.prototype = {
-    eval: function () { return this },
-    luma: function () { return (0.2126 * this.rgb[0] / 255) + (0.7152 * this.rgb[1] / 255) + (0.0722 * this.rgb[2] / 255); },
-
-    //
-    // If we have some transparency, the only way to represent it
-    // is via `rgba`. Otherwise, we use the hex representation,
-    // which has better compatibility with older browsers.
-    // Values are capped between `0` and `255`, rounded and zero-padded.
-    //
-    toCSS: function (env, doNotCompress) {
-        var compress = env && env.compress && !doNotCompress;
-        if (this.alpha < 1.0) {
-            return "rgba(" + this.rgb.map(function (c) {
-                return Math.round(c);
-            }).concat(this.alpha).join(',' + (compress ? '' : ' ')) + ")";
-        } else {
-            var color = this.rgb.map(function (i) {
-                i = Math.round(i);
-                i = (i > 255 ? 255 : (i < 0 ? 0 : i)).toString(16);
-                return i.length === 1 ? '0' + i : i;
-            }).join('');
-
-            if (compress) {
-                color = color.split('');
-
-                // Convert color to short format
-                if (color[0] == color[1] && color[2] == color[3] && color[4] == color[5]) {
-                    color = color[0] + color[2] + color[4];
-                } else {
-                    color = color.join('');
-                }
-            }
-
-            return '#' + color;
-        }
-    },
-
-    //
-    // Operations have to be done per-channel, if not,
-    // channels will spill onto each other. Once we have
-    // our result, in the form of an integer triplet,
-    // we create a new Color node to hold the result.
-    //
-    operate: function (env, op, other) {
-        var result = [];
-
-        if (! (other instanceof tree.Color)) {
-            other = other.toColor();
-        }
-
-        for (var c = 0; c < 3; c++) {
-            result[c] = tree.operate(env, op, this.rgb[c], other.rgb[c]);
-        }
-        return new(tree.Color)(result, this.alpha + other.alpha);
-    },
-
-    toHSL: function () {
-        var r = this.rgb[0] / 255,
-            g = this.rgb[1] / 255,
-            b = this.rgb[2] / 255,
-            a = this.alpha;
-
-        var max = Math.max(r, g, b), min = Math.min(r, g, b);
-        var h, s, l = (max + min) / 2, d = max - min;
-
-        if (max === min) {
-            h = s = 0;
-        } else {
-            s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
-
-            switch (max) {
-                case r: h = (g - b) / d + (g < b ? 6 : 0); break;
-                case g: h = (b - r) / d + 2;               break;
-                case b: h = (r - g) / d + 4;               break;
-            }
-            h /= 6;
-        }
-        return { h: h * 360, s: s, l: l, a: a };
-    },
-    //Adapted from http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
-    toHSV: function () {
-        var r = this.rgb[0] / 255,
-            g = this.rgb[1] / 255,
-            b = this.rgb[2] / 255,
-            a = this.alpha;
-
-        var max = Math.max(r, g, b), min = Math.min(r, g, b);
-        var h, s, v = max;
-
-        var d = max - min;
-        if (max === 0) {
-            s = 0;
-        } else {
-            s = d / max;
-        }
-
-        if (max === min) {
-            h = 0;
-        } else {
-            switch(max){
-                case r: h = (g - b) / d + (g < b ? 6 : 0); break;
-                case g: h = (b - r) / d + 2; break;
-                case b: h = (r - g) / d + 4; break;
-            }
-            h /= 6;
-        }
-        return { h: h * 360, s: s, v: v, a: a };
-    },
-    toARGB: function () {
-        var argb = [Math.round(this.alpha * 255)].concat(this.rgb);
-        return '#' + argb.map(function (i) {
-            i = Math.round(i);
-            i = (i > 255 ? 255 : (i < 0 ? 0 : i)).toString(16);
-            return i.length === 1 ? '0' + i : i;
-        }).join('');
-    },
-    compare: function (x) {
-        if (!x.rgb) {
-            return -1;
-        }
-
-        return (x.rgb[0] === this.rgb[0] &&
-            x.rgb[1] === this.rgb[1] &&
-            x.rgb[2] === this.rgb[2] &&
-            x.alpha === this.alpha) ? 0 : -1;
-    }
-};
-
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Comment = function (value, silent) {
-    this.value = value;
-    this.silent = !!silent;
-};
-tree.Comment.prototype = {
-    toCSS: function (env) {
-        return env.compress ? '' : this.value;
-    },
-    eval: function () { return this }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Condition = function (op, l, r, i, negate) {
-    this.op = op.trim();
-    this.lvalue = l;
-    this.rvalue = r;
-    this.index = i;
-    this.negate = negate;
-};
-tree.Condition.prototype.eval = function (env) {
-    var a = this.lvalue.eval(env),
-        b = this.rvalue.eval(env);
-
-    var i = this.index, result;
-
-    var result = (function (op) {
-        switch (op) {
-            case 'and':
-                return a && b;
-            case 'or':
-                return a || b;
-            default:
-                if (a.compare) {
-                    result = a.compare(b);
-                } else if (b.compare) {
-                    result = b.compare(a);
-                } else {
-                    throw { type: "Type",
-                            message: "Unable to perform comparison",
-                            index: i };
-                }
-                switch (result) {
-                    case -1: return op === '<' || op === '=<';
-                    case  0: return op === '=' || op === '>=' || op === '=<';
-                    case  1: return op === '>' || op === '>=';
-                }
-        }
-    })(this.op);
-    return this.negate ? !result : result;
-};
-
-})(require('../tree'));
-(function (tree) {
-
-//
-// A number with a unit
-//
-tree.Dimension = function (value, unit) {
-    this.value = parseFloat(value);
-    this.unit = (unit && unit instanceof tree.Unit) ? unit :
-      new(tree.Unit)(unit ? [unit] : undefined);
-};
-
-tree.Dimension.prototype = {
-    eval: function (env) {
-        return this;
-    },
-    toColor: function () {
-        return new(tree.Color)([this.value, this.value, this.value]);
-    },
-    toCSS: function (env) {
-        if ((!env || env.strictUnits !== false) && !this.unit.isSingular()) {
-            throw new Error("Multiple units in dimension. Correct the units or use the unit function. Bad unit: "+this.unit.toString());
-        }
-
-        var value = this.value,
-            strValue = String(value);
-
-        if (value !== 0 && value < 0.000001 && value > -0.000001) {
-            // would be output 1e-6 etc.
-            strValue = value.toFixed(20).replace(/0+$/, "");
-        }
-
-        if (env && env.compress) {
-            // Zero values doesn't need a unit
-            if (value === 0 && !this.unit.isAngle()) {
-                return strValue;
-            }
-
-            // Float values doesn't need a leading zero
-            if (value > 0 && value < 1) {
-                strValue = (strValue).substr(1);
-            }
-        }
-
-        return this.unit.isEmpty() ? strValue : (strValue + this.unit.toCSS());
-    },
-
-    // In an operation between two Dimensions,
-    // we default to the first Dimension's unit,
-    // so `1px + 2` will yield `3px`.
-    operate: function (env, op, other) {
-        var value = tree.operate(env, op, this.value, other.value),
-            unit = this.unit.clone();
-
-        if (op === '+' || op === '-') {
-            if (unit.numerator.length === 0 && unit.denominator.length === 0) {
-                unit.numerator = other.unit.numerator.slice(0);
-                unit.denominator = other.unit.denominator.slice(0);
-            } else if (other.unit.numerator.length == 0 && unit.denominator.length == 0) {
-                // do nothing
-            } else {
-                other = other.convertTo(this.unit.usedUnits());
-
-                if(env.strictUnits !== false && other.unit.toString() !== unit.toString()) {
-                  throw new Error("Incompatible units. Change the units or use the unit function. Bad units: '" + unit.toString() +
-                    "' and '" + other.unit.toString() + "'.");
-                }
-
-                value = tree.operate(env, op, this.value, other.value);
-            }
-        } else if (op === '*') {
-            unit.numerator = unit.numerator.concat(other.unit.numerator).sort();
-            unit.denominator = unit.denominator.concat(other.unit.denominator).sort();
-            unit.cancel();
-        } else if (op === '/') {
-            unit.numerator = unit.numerator.concat(other.unit.denominator).sort();
-            unit.denominator = unit.denominator.concat(other.unit.numerator).sort();
-            unit.cancel();
-        }
-        return new(tree.Dimension)(value, unit);
-    },
-
-    compare: function (other) {
-        if (other instanceof tree.Dimension) {
-            var a = this.unify(), b = other.unify(),
-                aValue = a.value, bValue = b.value;
-
-            if (bValue > aValue) {
-                return -1;
-            } else if (bValue < aValue) {
-                return 1;
-            } else {
-                if (!b.unit.isEmpty() && a.unit.compare(b) !== 0) {
-                    return -1;
-                }
-                return 0;
-            }
-        } else {
-            return -1;
-        }
-    },
-
-    unify: function () {
-      return this.convertTo({ length: 'm', duration: 's', angle: 'rad' });
-    },
-
-    convertTo: function (conversions) {
-      var value = this.value, unit = this.unit.clone(),
-          i, groupName, group, conversion, targetUnit, derivedConversions = {};
-
-      if (typeof conversions === 'string') {
-          for(i in tree.UnitConversions) {
-              if (tree.UnitConversions[i].hasOwnProperty(conversions)) {
-                  derivedConversions = {};
-                  derivedConversions[i] = conversions;
-              }
-          }
-          conversions = derivedConversions;
-      }
-
-      for (groupName in conversions) {
-        if (conversions.hasOwnProperty(groupName)) {
-          targetUnit = conversions[groupName];
-          group = tree.UnitConversions[groupName];
-
-          unit.map(function (atomicUnit, denominator) {
-            if (group.hasOwnProperty(atomicUnit)) {
-              if (denominator) {
-                value = value / (group[atomicUnit] / group[targetUnit]);
-              } else {
-                value = value * (group[atomicUnit] / group[targetUnit]);
-              }
-
-              return targetUnit;
-            }
-
-            return atomicUnit;
-          });
-        }
-      }
-
-      unit.cancel();
-
-      return new(tree.Dimension)(value, unit);
-    }
-};
-
-// http://www.w3.org/TR/css3-values/#absolute-lengths
-tree.UnitConversions = {
-  length: {
-     'm': 1,
-    'cm': 0.01,
-    'mm': 0.001,
-    'in': 0.0254,
-    'pt': 0.0254 / 72,
-    'pc': 0.0254 / 72 * 12
-  },
-  duration: {
-    's': 1,
-    'ms': 0.001
-  },
-  angle: {
-    'rad': 1/(2*Math.PI),
-    'deg': 1/360,
-    'grad': 1/400,
-    'turn': 1
-  }
-};
-
-tree.Unit = function (numerator, denominator) {
-  this.numerator = numerator ? numerator.slice(0).sort() : [];
-  this.denominator = denominator ? denominator.slice(0).sort() : [];
-};
-
-tree.Unit.prototype = {
-  clone: function () {
-    return new tree.Unit(this.numerator.slice(0), this.denominator.slice(0));
-  },
-
-  toCSS: function () {
-    if (this.numerator.length >= 1) {
-        return this.numerator[0];
-    }
-    if (this.denominator.length >= 1) {
-        return this.denominator[0];
-    }
-    return "";
-  },
-
-  toString: function () {
-      var i, returnStr = this.numerator.join("*");
-      for (i = 0; i < this.denominator.length; i++) {
-          returnStr += "/" + this.denominator[i];
-      }
-      return returnStr;
-  },
-
-  compare: function (other) {
-    return this.is(other.toCSS()) ? 0 : -1;
-  },
-
-  is: function (unitString) {
-    return this.toCSS() === unitString;
-  },
-
-  isAngle: function () {
-    return tree.UnitConversions.angle.hasOwnProperty(this.toCSS());
-  },
-
-  isEmpty: function () {
-    return this.numerator.length == 0 && this.denominator.length == 0;
-  },
-
-  isSingular: function() {
-      return this.numerator.length <= 1 && this.denominator.length == 0;
-  },
-
-  map: function(callback) {
-    var i;
-
-    for (i = 0; i < this.numerator.length; i++) {
-      this.numerator[i] = callback(this.numerator[i], false);
-    }
-
-    for (i = 0; i < this.denominator.length; i++) {
-      this.denominator[i] = callback(this.denominator[i], true);
-    }
-  },
-
-  usedUnits: function() {
-    var group, groupName, result = {};
-
-    for (groupName in tree.UnitConversions) {
-      if (tree.UnitConversions.hasOwnProperty(groupName)) {
-        group = tree.UnitConversions[groupName];
-
-        this.map(function (atomicUnit) {
-          if (group.hasOwnProperty(atomicUnit) && !result[groupName]) {
-            result[groupName] = atomicUnit;
-          }
-
-          return atomicUnit;
-        });
-      }
-    }
-
-    return result;
-  },
-
-  cancel: function () {
-    var counter = {}, atomicUnit, i;
-
-    for (i = 0; i < this.numerator.length; i++) {
-      atomicUnit = this.numerator[i];
-      counter[atomicUnit] = (counter[atomicUnit] || 0) + 1;
-    }
-
-    for (i = 0; i < this.denominator.length; i++) {
-      atomicUnit = this.denominator[i];
-      counter[atomicUnit] = (counter[atomicUnit] || 0) - 1;
-    }
-
-    this.numerator = [];
-    this.denominator = [];
-
-    for (atomicUnit in counter) {
-      if (counter.hasOwnProperty(atomicUnit)) {
-        var count = counter[atomicUnit];
-
-        if (count > 0) {
-          for (i = 0; i < count; i++) {
-            this.numerator.push(atomicUnit);
-          }
-        } else if (count < 0) {
-          for (i = 0; i < -count; i++) {
-            this.denominator.push(atomicUnit);
-          }
-        }
-      }
-    }
-
-    this.numerator.sort();
-    this.denominator.sort();
-  }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Directive = function (name, value) {
-    this.name = name;
-
-    if (Array.isArray(value)) {
-        this.ruleset = new(tree.Ruleset)([], value);
-        this.ruleset.allowImports = true;
-    } else {
-        this.value = value;
-    }
-};
-tree.Directive.prototype = {
-    toCSS: function (ctx, env) {
-        if (this.ruleset) {
-            this.ruleset.root = true;
-            return this.name + (env.compress ? '{' : ' {\n  ') +
-                   this.ruleset.toCSS(ctx, env).trim().replace(/\n/g, '\n  ') +
-                               (env.compress ? '}': '\n}\n');
-        } else {
-            return this.name + ' ' + this.value.toCSS() + ';\n';
-        }
-    },
-    eval: function (env) {
-        var evaldDirective = this;
-        if (this.ruleset) {
-            env.frames.unshift(this);
-            evaldDirective = new(tree.Directive)(this.name);
-            evaldDirective.ruleset = this.ruleset.eval(env);
-            env.frames.shift();
-        }
-        return evaldDirective;
-    },
-    variable: function (name) { return tree.Ruleset.prototype.variable.call(this.ruleset, name) },
-    find: function () { return tree.Ruleset.prototype.find.apply(this.ruleset, arguments) },
-    rulesets: function () { return tree.Ruleset.prototype.rulesets.apply(this.ruleset) }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Element = function (combinator, value, index) {
-    this.combinator = combinator instanceof tree.Combinator ?
-                      combinator : new(tree.Combinator)(combinator);
-
-    if (typeof(value) === 'string') {
-        this.value = value.trim();
-    } else if (value) {
-        this.value = value;
-    } else {
-        this.value = "";
-    }
-    this.index = index;
-};
-tree.Element.prototype.eval = function (env) {
-    return new(tree.Element)(this.combinator,
-                             this.value.eval ? this.value.eval(env) : this.value,
-                             this.index);
-};
-tree.Element.prototype.toCSS = function (env) {
-  var value = (this.value.toCSS ? this.value.toCSS(env) : this.value);
-  if (value == '' && this.combinator.value.charAt(0) == '&') {
-    return '';
-  } else {
-    return this.combinator.toCSS(env || {}) + value;
-  }
-};
-
-tree.Combinator = function (value) {
-    if (value === ' ') {
-        this.value = ' ';
-    } else {
-        this.value = value ? value.trim() : "";
-    }
-};
-tree.Combinator.prototype.toCSS = function (env) {
-    return {
-        ''  : '',
-        ' ' : ' ',
-        ':' : ' :',
-        '+' : env.compress ? '+' : ' + ',
-        '~' : env.compress ? '~' : ' ~ ',
-        '>' : env.compress ? '>' : ' > ',
-        '|' : env.compress ? '|' : ' | '
-    }[this.value];
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Expression = function (value) { this.value = value; };
-tree.Expression.prototype = {
-    eval: function (env) {
-        var returnValue,
-            inParenthesis = this.parens && !this.parensInOp,
-            doubleParen = false;
-        if (inParenthesis) {
-            env.inParenthesis();
-        }
-        if (this.value.length > 1) {
-            returnValue = new(tree.Expression)(this.value.map(function (e) {
-                return e.eval(env);
-            }));
-        } else if (this.value.length === 1) {
-            if (this.value[0].parens && !this.value[0].parensInOp) {
-                doubleParen = true;
-            }
-            returnValue = this.value[0].eval(env);
-        } else {
-            returnValue = this;
-        }
-        if (inParenthesis) {
-            env.outOfParenthesis();
-        }
-        if (this.parens && this.parensInOp && !(env.isMathsOn()) && !doubleParen) {
-            returnValue = new(tree.Paren)(returnValue);
-        }
-        return returnValue;
-    },
-    toCSS: function (env) {
-        return this.value.map(function (e) {
-            return e.toCSS ? e.toCSS(env) : '';
-        }).join(' ');
-    },
-    throwAwayComments: function () {
-        this.value = this.value.filter(function(v) {
-            return !(v instanceof tree.Comment);
-        });
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Extend = function Extend(elements, index) {
-    this.selector = new(tree.Selector)(elements);
-    this.index = index;
-};
-
-tree.Extend.prototype.eval = function Extend_eval(env, selectors) {
-    var selfSelectors = findSelfSelectors(selectors || env.selectors),
-        targetValue = this.selector.elements[0].value;
-
-    env.frames.forEach(function(frame) {
-        frame.rulesets().forEach(function(rule) {
-            rule.selectors.forEach(function(selector) {
-                selector.elements.forEach(function(element, idx) {
-                    if (element.value === targetValue) {
-                        selfSelectors.forEach(function(_selector) {
-                            _selector.elements[0] = new tree.Element(
-                                element.combinator,
-                                _selector.elements[0].value,
-                                _selector.elements[0].index
-                            );
-                            rule.selectors.push(new tree.Selector(
-                                selector.elements
-                                    .slice(0, idx)
-                                    .concat(_selector.elements)
-                                    .concat(selector.elements.slice(idx + 1))
-                            ));
-                        });
-                    }
-                });
-            });
-        });
-    });
-    return this;
-};
-
-function findSelfSelectors(selectors) {
-    var ret = [];
-
-    (function loop(elem, i) {
-        if (selectors[i] && selectors[i].length) {
-            selectors[i].forEach(function(s) {
-                loop(s.elements.concat(elem), i + 1);
-            });
-        }
-        else {
-            ret.push({ elements: elem });
-        }
-    })([], 0);
-
-    return ret;
-}
-
-
-})(require('../tree'));
-(function (tree) {
-//
-// CSS @import node
-//
-// The general strategy here is that we don't want to wait
-// for the parsing to be completed, before we start importing
-// the file. That's because in the context of a browser,
-// most of the time will be spent waiting for the server to respond.
-//
-// On creation, we push the import path to our import queue, though
-// `import,push`, we also pass it a callback, which it'll call once
-// the file has been fetched, and parsed.
-//
-tree.Import = function (path, imports, features, once, index, rootpath) {
-    var that = this;
-
-    this.once = once;
-    this.index = index;
-    this._path = path;
-    this.features = features;
-    this.rootpath = rootpath;
-
-    // The '.less' extension is optional
-    if (path instanceof tree.Quoted) {
-        this.path = /(\.[a-z]*$)|([\?;].*)$/.test(path.value) ? path.value : path.value + '.less';
-    } else {
-        this.path = path.value.value || path.value;
-    }
-
-    this.css = /css([\?;].*)?$/.test(this.path);
-
-    // Only pre-compile .less files
-    if (! this.css) {
-        imports.push(this.path, function (e, root, imported) {
-            if (e) { e.index = index; }
-            if (imported && that.once) { that.skip = imported; }
-            that.root = root || new(tree.Ruleset)([], []);
-        });
-    }
-};
-
-//
-// The actual import node doesn't return anything, when converted to CSS.
-// The reason is that it's used at the evaluation stage, so that the rules
-// it imports can be treated like any other rules.
-//
-// In `eval`, we make sure all Import nodes get evaluated, recursively, so
-// we end up with a flat structure, which can easily be imported in the parent
-// ruleset.
-//
-tree.Import.prototype = {
-    toCSS: function (env) {
-        var features = this.features ? ' ' + this.features.toCSS(env) : '';
-
-        if (this.css) {
-            // Add the base path if the import is relative
-            if (typeof this._path.value === "string" && !/^(?:[a-z-]+:|\/)/.test(this._path.value)) {
-                this._path.value = this.rootpath + this._path.value;
-            }
-            return "@import " + this._path.toCSS() + features + ';\n';
-        } else {
-            return "";
-        }
-    },
-    eval: function (env) {
-        var ruleset, features = this.features && this.features.eval(env);
-
-        if (this.skip) { return []; }
-
-        if (this.css) {
-            return new(tree.Import)(this._path, null, features, this.once, this.index, this.rootpath);
-        } else {
-            ruleset = new(tree.Ruleset)([], this.root.rules.slice(0));
-
-            ruleset.evalImports(env);
-
-            return this.features ? new(tree.Media)(ruleset.rules, this.features.value) : ruleset.rules;
-        }
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.JavaScript = function (string, index, escaped) {
-    this.escaped = escaped;
-    this.expression = string;
-    this.index = index;
-};
-tree.JavaScript.prototype = {
-    eval: function (env) {
-        var result,
-            that = this,
-            context = {};
-
-        var expression = this.expression.replace(/@\{([\w-]+)\}/g, function (_, name) {
-            return tree.jsify(new(tree.Variable)('@' + name, that.index).eval(env));
-        });
-
-        try {
-            expression = new(Function)('return (' + expression + ')');
-        } catch (e) {
-            throw { message: "JavaScript evaluation error: `" + expression + "`" ,
-                    index: this.index };
-        }
-
-        for (var k in env.frames[0].variables()) {
-            context[k.slice(1)] = {
-                value: env.frames[0].variables()[k].value,
-                toJS: function () {
-                    return this.value.eval(env).toCSS();
-                }
-            };
-        }
-
-        try {
-            result = expression.call(context);
-        } catch (e) {
-            throw { message: "JavaScript evaluation error: '" + e.name + ': ' + e.message + "'" ,
-                    index: this.index };
-        }
-        if (typeof(result) === 'string') {
-            return new(tree.Quoted)('"' + result + '"', result, this.escaped, this.index);
-        } else if (Array.isArray(result)) {
-            return new(tree.Anonymous)(result.join(', '));
-        } else {
-            return new(tree.Anonymous)(result);
-        }
-    }
-};
-
-})(require('../tree'));
-
-(function (tree) {
-
-tree.Keyword = function (value) { this.value = value };
-tree.Keyword.prototype = {
-    eval: function () { return this },
-    toCSS: function () { return this.value },
-    compare: function (other) {
-        if (other instanceof tree.Keyword) {
-            return other.value === this.value ? 0 : 1;
-        } else {
-            return -1;
-        }
-    }
-};
-
-tree.True = new(tree.Keyword)('true');
-tree.False = new(tree.Keyword)('false');
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Media = function (value, features) {
-    var selectors = this.emptySelectors();
-
-    this.features = new(tree.Value)(features);
-    this.ruleset = new(tree.Ruleset)(selectors, value);
-    this.ruleset.allowImports = true;
-};
-tree.Media.prototype = {
-    toCSS: function (ctx, env) {
-        var features = this.features.toCSS(env);
-
-        this.ruleset.root = (ctx.length === 0 || ctx[0].multiMedia);
-        return '@media ' + features + (env.compress ? '{' : ' {\n  ') +
-               this.ruleset.toCSS(ctx, env).trim().replace(/\n/g, '\n  ') +
-                           (env.compress ? '}': '\n}\n');
-    },
-    eval: function (env) {
-        if (!env.mediaBlocks) {
-            env.mediaBlocks = [];
-            env.mediaPath = [];
-        }
-
-        var media = new(tree.Media)([], []);
-        if(this.debugInfo) {
-            this.ruleset.debugInfo = this.debugInfo;
-            media.debugInfo = this.debugInfo;
-        }
-        var strictMathsBypass = false;
-        if (env.strictMaths === false) {
-            strictMathsBypass = true;
-            env.strictMaths = true;
-        }
-        try {
-            media.features = this.features.eval(env);
-        }
-        finally {
-            if (strictMathsBypass) {
-                env.strictMaths = false;
-            }
-        }
-
-        env.mediaPath.push(media);
-        env.mediaBlocks.push(media);
-
-        env.frames.unshift(this.ruleset);
-        media.ruleset = this.ruleset.eval(env);
-        env.frames.shift();
-
-        env.mediaPath.pop();
-
-        return env.mediaPath.length === 0 ? media.evalTop(env) :
-                    media.evalNested(env)
-    },
-    variable: function (name) { return tree.Ruleset.prototype.variable.call(this.ruleset, name) },
-    find: function () { return tree.Ruleset.prototype.find.apply(this.ruleset, arguments) },
-    rulesets: function () { return tree.Ruleset.prototype.rulesets.apply(this.ruleset) },
-    emptySelectors: function() {
-        var el = new(tree.Element)('', '&', 0);
-        return [new(tree.Selector)([el])];
-    },
-
-    evalTop: function (env) {
-        var result = this;
-
-        // Render all dependent Media blocks.
-        if (env.mediaBlocks.length > 1) {
-            var selectors = this.emptySelectors();
-            result = new(tree.Ruleset)(selectors, env.mediaBlocks);
-            result.multiMedia = true;
-        }
-
-        delete env.mediaBlocks;
-        delete env.mediaPath;
-
-        return result;
-    },
-    evalNested: function (env) {
-        var i, value,
-            path = env.mediaPath.concat([this]);
-
-        // Extract the media-query conditions separated with `,` (OR).
-        for (i = 0; i < path.length; i++) {
-            value = path[i].features instanceof tree.Value ?
-                        path[i].features.value : path[i].features;
-            path[i] = Array.isArray(value) ? value : [value];
-        }
-
-        // Trace all permutations to generate the resulting media-query.
-        //
-        // (a, b and c) with nested (d, e) ->
-        //    a and d
-        //    a and e
-        //    b and c and d
-        //    b and c and e
-        this.features = new(tree.Value)(this.permute(path).map(function (path) {
-            path = path.map(function (fragment) {
-                return fragment.toCSS ? fragment : new(tree.Anonymous)(fragment);
-            });
-
-            for(i = path.length - 1; i > 0; i--) {
-                path.splice(i, 0, new(tree.Anonymous)("and"));
-            }
-
-            return new(tree.Expression)(path);
-        }));
-
-        // Fake a tree-node that doesn't output anything.
-        return new(tree.Ruleset)([], []);
-    },
-    permute: function (arr) {
-      if (arr.length === 0) {
-          return [];
-      } else if (arr.length === 1) {
-          return arr[0];
-      } else {
-          var result = [];
-          var rest = this.permute(arr.slice(1));
-          for (var i = 0; i < rest.length; i++) {
-              for (var j = 0; j < arr[0].length; j++) {
-                  result.push([arr[0][j]].concat(rest[i]));
-              }
-          }
-          return result;
-      }
-    },
-    bubbleSelectors: function (selectors) {
-      this.ruleset = new(tree.Ruleset)(selectors.slice(0), [this.ruleset]);
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.mixin = {};
-tree.mixin.Call = function (elements, args, index, filename, important) {
-    this.selector = new(tree.Selector)(elements);
-    this.arguments = args;
-    this.index = index;
-    this.filename = filename;
-    this.important = important;
-};
-tree.mixin.Call.prototype = {
-    eval: function (env) {
-        var mixins, mixin, args, rules = [], match = false, i, m, f, isRecursive, isOneFound;
-
-        args = this.arguments && this.arguments.map(function (a) {
-            return { name: a.name, value: a.value.eval(env) };
-        });
-
-        for (i = 0; i < env.frames.length; i++) {
-            if ((mixins = env.frames[i].find(this.selector)).length > 0) {
-                isOneFound = true;
-                for (m = 0; m < mixins.length; m++) {
-                    mixin = mixins[m];
-                    isRecursive = false;
-                    for(f = 0; f < env.frames.length; f++) {
-                        if ((!(mixin instanceof tree.mixin.Definition)) && mixin === (env.frames[f].originalRuleset || env.frames[f])) {
-                            isRecursive = true;
-                            break;
-                        }
-                    }
-                    if (isRecursive) {
-                        continue;
-                    }
-                    if (mixin.matchArgs(args, env)) {
-                        if (!mixin.matchCondition || mixin.matchCondition(args, env)) {
-                            try {
-                                Array.prototype.push.apply(
-                                      rules, mixin.eval(env, args, this.important).rules);
-                            } catch (e) {
-                                throw { message: e.message, index: this.index, filename: this.filename, stack: e.stack };
-                            }
-                        }
-                        match = true;
-                    }
-                }
-                if (match) {
-                    return rules;
-                }
-            }
-        }
-        if (isOneFound) {
-            throw { type:    'Runtime',
-                    message: 'No matching definition was found for `' +
-                              this.selector.toCSS().trim() + '('      +
-                              (args ? args.map(function (a) {
-                                  var argValue = "";
-                                  if (a.name) {
-                                      argValue += a.name + ":";
-                                  }
-                                  if (a.value.toCSS) {
-                                      argValue += a.value.toCSS();
-                                  } else {
-                                      argValue += "???";
-                                  }
-                                  return argValue;
-                              }).join(', ') : "") + ")`",
-                    index:   this.index, filename: this.filename };
-        } else {
-            throw { type: 'Name',
-                message: this.selector.toCSS().trim() + " is undefined",
-                index: this.index, filename: this.filename };
-        }
-    }
-};
-
-tree.mixin.Definition = function (name, params, rules, condition, variadic) {
-    this.name = name;
-    this.selectors = [new(tree.Selector)([new(tree.Element)(null, name)])];
-    this.params = params;
-    this.condition = condition;
-    this.variadic = variadic;
-    this.arity = params.length;
-    this.rules = rules;
-    this._lookups = {};
-    this.required = params.reduce(function (count, p) {
-        if (!p.name || (p.name && !p.value)) { return count + 1 }
-        else                                 { return count }
-    }, 0);
-    this.parent = tree.Ruleset.prototype;
-    this.frames = [];
-};
-tree.mixin.Definition.prototype = {
-    toCSS:     function ()     { return "" },
-    variable:  function (name) { return this.parent.variable.call(this, name) },
-    variables: function ()     { return this.parent.variables.call(this) },
-    find:      function ()     { return this.parent.find.apply(this, arguments) },
-    rulesets:  function ()     { return this.parent.rulesets.apply(this) },
-
-    evalParams: function (env, mixinEnv, args, evaldArguments) {
-        var frame = new(tree.Ruleset)(null, []),
-            varargs, arg,
-            params = this.params.slice(0),
-            i, j, val, name, isNamedFound, argIndex;
-
-        mixinEnv = new tree.evalEnv(mixinEnv, [frame].concat(mixinEnv.frames));
-
-        if (args) {
-            args = args.slice(0);
-
-            for(i = 0; i < args.length; i++) {
-                arg = args[i];
-                if (name = (arg && arg.name)) {
-                    isNamedFound = false;
-                    for(j = 0; j < params.length; j++) {
-                        if (!evaldArguments[j] && name === params[j].name) {
-                            evaldArguments[j] = arg.value.eval(env);
-                            frame.rules.unshift(new(tree.Rule)(name, arg.value.eval(env)));
-                            isNamedFound = true;
-                            break;
-                        }
-                    }
-                    if (isNamedFound) {
-                        args.splice(i, 1);
-                        i--;
-                        continue;
-                    } else {
-                        throw { type: 'Runtime', message: "Named argument for " + this.name +
-                            ' ' + args[i].name + ' not found' };
-                    }
-                }
-            }
-        }
-        argIndex = 0;
-        for (i = 0; i < params.length; i++) {
-            if (evaldArguments[i]) continue;
-
-            arg = args && args[argIndex];
-
-            if (name = params[i].name) {
-                if (params[i].variadic && args) {
-                    varargs = [];
-                    for (j = argIndex; j < args.length; j++) {
-                        varargs.push(args[j].value.eval(env));
-                    }
-                    frame.rules.unshift(new(tree.Rule)(name, new(tree.Expression)(varargs).eval(env)));
-                } else {
-                    val = arg && arg.value;
-                    if (val) {
-                        val = val.eval(env);
-                    } else if (params[i].value) {
-                        val = params[i].value.eval(mixinEnv);
-                        frame.resetCache();
-                    } else {
-                        throw { type: 'Runtime', message: "wrong number of arguments for " + this.name +
-                            ' (' + args.length + ' for ' + this.arity + ')' };
-                    }
-
-                    frame.rules.unshift(new(tree.Rule)(name, val));
-                    evaldArguments[i] = val;
-                }
-            }
-
-            if (params[i].variadic && args) {
-                for (j = argIndex; j < args.length; j++) {
-                    evaldArguments[j] = args[j].value.eval(env);
-                }
-            }
-            argIndex++;
-        }
-
-        return frame;
-    },
-    eval: function (env, args, important) {
-        var _arguments = [],
-            mixinFrames = this.frames.concat(env.frames),
-            frame = this.evalParams(env, new(tree.evalEnv)(env, mixinFrames), args, _arguments),
-            context, rules, start, ruleset;
-
-        frame.rules.unshift(new(tree.Rule)('@arguments', new(tree.Expression)(_arguments).eval(env)));
-
-        rules = important ?
-            this.parent.makeImportant.apply(this).rules : this.rules.slice(0);
-
-        ruleset = new(tree.Ruleset)(null, rules).eval(new(tree.evalEnv)(env,
-                                                    [this, frame].concat(mixinFrames)));
-        ruleset.originalRuleset = this;
-        return ruleset;
-    },
-    matchCondition: function (args, env) {
-
-        if (this.condition && !this.condition.eval(
-            new(tree.evalEnv)(env,
-                [this.evalParams(env, new(tree.evalEnv)(env, this.frames.concat(env.frames)), args, [])]
-                    .concat(env.frames)))) {
-            return false;
-        }
-        return true;
-    },
-    matchArgs: function (args, env) {
-        var argsLength = (args && args.length) || 0, len, frame;
-
-        if (! this.variadic) {
-            if (argsLength < this.required)                               { return false }
-            if (argsLength > this.params.length)                          { return false }
-            if ((this.required > 0) && (argsLength > this.params.length)) { return false }
-        }
-
-        len = Math.min(argsLength, this.arity);
-
-        for (var i = 0; i < len; i++) {
-            if (!this.params[i].name && !this.params[i].variadic) {
-                if (args[i].value.eval(env).toCSS() != this.params[i].value.eval(env).toCSS()) {
-                    return false;
-                }
-            }
-        }
-        return true;
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Negative = function (node) {
-    this.value = node;
-};
-tree.Negative.prototype = {
-    toCSS: function (env) {
-        return '-' + this.value.toCSS(env);
-    },
-    eval: function (env) {
-        if (env.isMathsOn()) {
-            return (new(tree.Operation)('*', [new(tree.Dimension)(-1), this.value])).eval(env);
-        }
-        return new(tree.Negative)(this.value.eval(env));
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Operation = function (op, operands, isSpaced) {
-    this.op = op.trim();
-    this.operands = operands;
-    this.isSpaced = isSpaced;
-};
-tree.Operation.prototype.eval = function (env) {
-    var a = this.operands[0].eval(env),
-        b = this.operands[1].eval(env),
-        temp;
-
-    if (env.isMathsOn()) {
-        if (a instanceof tree.Dimension && b instanceof tree.Color) {
-            if (this.op === '*' || this.op === '+') {
-                temp = b, b = a, a = temp;
-            } else {
-                throw { type: "Operation",
-                        message: "Can't substract or divide a color from a number" };
-            }
-        }
-        if (!a.operate) {
-            throw { type: "Operation",
-                    message: "Operation on an invalid type" };
-        }
-
-        return a.operate(env, this.op, b);
-    } else {
-        return new(tree.Operation)(this.op, [a, b], this.isSpaced);
-    }
-};
-tree.Operation.prototype.toCSS = function (env) {
-    var separator = this.isSpaced ? " " : "";
-    return this.operands[0].toCSS() + separator + this.op + separator + this.operands[1].toCSS();
-};
-
-tree.operate = function (env, op, a, b) {
-    switch (op) {
-        case '+': return a + b;
-        case '-': return a - b;
-        case '*': return a * b;
-        case '/': return a / b;
-    }
-};
-
-})(require('../tree'));
-
-(function (tree) {
-
-tree.Paren = function (node) {
-    this.value = node;
-};
-tree.Paren.prototype = {
-    toCSS: function (env) {
-        return '(' + this.value.toCSS(env).trim() + ')';
-    },
-    eval: function (env) {
-        return new(tree.Paren)(this.value.eval(env));
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Quoted = function (str, content, escaped, i) {
-    this.escaped = escaped;
-    this.value = content || '';
-    this.quote = str.charAt(0);
-    this.index = i;
-};
-tree.Quoted.prototype = {
-    toCSS: function () {
-        if (this.escaped) {
-            return this.value;
-        } else {
-            return this.quote + this.value + this.quote;
-        }
-    },
-    eval: function (env) {
-        var that = this;
-        var value = this.value.replace(/`([^`]+)`/g, function (_, exp) {
-            return new(tree.JavaScript)(exp, that.index, true).eval(env).value;
-        }).replace(/@\{([\w-]+)\}/g, function (_, name) {
-            var v = new(tree.Variable)('@' + name, that.index).eval(env, true);
-            return (v instanceof tree.Quoted) ? v.value : v.toCSS();
-        });
-        return new(tree.Quoted)(this.quote + value + this.quote, value, this.escaped, this.index);
-    },
-    compare: function (x) {
-        if (!x.toCSS) {
-            return -1;
-        }
-
-        var left = this.toCSS(),
-            right = x.toCSS();
-
-        if (left === right) {
-            return 0;
-        }
-
-        return left < right ? -1 : 1;
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Rule = function (name, value, important, index, inline) {
-    this.name = name;
-    this.value = (value instanceof tree.Value) ? value : new(tree.Value)([value]);
-    this.important = important ? ' ' + important.trim() : '';
-    this.index = index;
-    this.inline = inline || false;
-
-    if (name.charAt(0) === '@') {
-        this.variable = true;
-    } else { this.variable = false }
-};
-tree.Rule.prototype.toCSS = function (env) {
-    if (this.variable) { return "" }
-    else {
-        return this.name + (env.compress ? ':' : ': ') +
-               this.value.toCSS(env) +
-               this.important + (this.inline ? "" : ";");
-    }
-};
-
-tree.Rule.prototype.eval = function (env) {
-    var strictMathsBypass = false;
-    if (this.name === "font" && env.strictMaths === false) {
-        strictMathsBypass = true;
-        env.strictMaths = true;
-    }
-    try {
-        return new(tree.Rule)(this.name,
-                          this.value.eval(env),
-                          this.important,
-                          this.index, this.inline);
-    }
-    finally {
-        if (strictMathsBypass) {
-            env.strictMaths = false;
-        }
-    }
-};
-
-tree.Rule.prototype.makeImportant = function () {
-    return new(tree.Rule)(this.name,
-                          this.value,
-                          "!important",
-                          this.index, this.inline);
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Ruleset = function (selectors, rules, strictImports) {
-    this.selectors = selectors;
-    this.rules = rules;
-    this._lookups = {};
-    this.strictImports = strictImports;
-};
-tree.Ruleset.prototype = {
-    eval: function (env) {
-        var selectors = this.selectors && this.selectors.map(function (s) { return s.eval(env) });
-        var ruleset = new(tree.Ruleset)(selectors, this.rules.slice(0), this.strictImports);
-        var rules;
-
-        ruleset.originalRuleset = this;
-        ruleset.root = this.root;
-        ruleset.allowImports = this.allowImports;
-
-        if(this.debugInfo) {
-            ruleset.debugInfo = this.debugInfo;
-        }
-
-        // push the current ruleset to the frames stack
-        env.frames.unshift(ruleset);
-
-        // currrent selectors
-        if (!env.selectors) {
-            env.selectors = [];
-        }
-        env.selectors.unshift(this.selectors);
-
-        // Evaluate imports
-        if (ruleset.root || ruleset.allowImports || !ruleset.strictImports) {
-            ruleset.evalImports(env);
-        }
-
-        // Store the frames around mixin definitions,
-        // so they can be evaluated like closures when the time comes.
-        for (var i = 0; i < ruleset.rules.length; i++) {
-            if (ruleset.rules[i] instanceof tree.mixin.Definition) {
-                ruleset.rules[i].frames = env.frames.slice(0);
-            }
-        }
-
-        var mediaBlockCount = (env.mediaBlocks && env.mediaBlocks.length) || 0;
-
-        // Evaluate mixin calls.
-        for (var i = 0; i < ruleset.rules.length; i++) {
-            if (ruleset.rules[i] instanceof tree.mixin.Call) {
-                rules = ruleset.rules[i].eval(env).filter(function(r) {
-                    if ((r instanceof tree.Rule) && r.variable) {
-                        // do not pollute the scope if the variable is
-                        // already there. consider returning false here
-                        // but we need a way to "return" variable from mixins
-                        return !(ruleset.variable(r.name));
-                    }
-                    return true;
-                });
-                ruleset.rules.splice.apply(ruleset.rules, [i, 1].concat(rules));
-                i += rules.length-1;
-                ruleset.resetCache();
-            }
-        }
-
-        if (this.selectors) {
-            for (var i = 0; i < this.selectors.length; i++) {
-                if (this.selectors[i].extend) {
-                    this.selectors[i].extend.eval(env, [[this.selectors[i]]].concat(env.selectors.slice(1)));
-                }
-            }
-        }
-
-        // Evaluate everything else
-        for (var i = 0, rule; i < ruleset.rules.length; i++) {
-            rule = ruleset.rules[i];
-
-            if (! (rule instanceof tree.mixin.Definition)) {
-                ruleset.rules[i] = rule.eval ? rule.eval(env) : rule;
-            }
-        }
-
-        // Pop the stack
-        env.frames.shift();
-        env.selectors.shift();
-
-        if (env.mediaBlocks) {
-            for(var i = mediaBlockCount; i < env.mediaBlocks.length; i++) {
-                env.mediaBlocks[i].bubbleSelectors(selectors);
-            }
-        }
-
-        return ruleset;
-    },
-    evalImports: function(env) {
-        var i, rules;
-        for (i = 0; i < this.rules.length; i++) {
-            if (this.rules[i] instanceof tree.Import) {
-                rules = this.rules[i].eval(env);
-                if (typeof rules.length === "number") {
-                    this.rules.splice.apply(this.rules, [i, 1].concat(rules));
-                    i+= rules.length-1;
-                } else {
-                    this.rules.splice(i, 1, rules);
-                }
-                this.resetCache();
-            }
-        }
-    },
-    makeImportant: function() {
-        return new tree.Ruleset(this.selectors, this.rules.map(function (r) {
-                    if (r.makeImportant) {
-                        return r.makeImportant();
-                    } else {
-                        return r;
-                    }
-                }), this.strictImports);
-    },
-    matchArgs: function (args) {
-        return !args || args.length === 0;
-    },
-    resetCache: function () {
-        this._rulesets = null;
-        this._variables = null;
-        this._lookups = {};
-    },
-    variables: function () {
-        if (this._variables) { return this._variables }
-        else {
-            return this._variables = this.rules.reduce(function (hash, r) {
-                if (r instanceof tree.Rule && r.variable === true) {
-                    hash[r.name] = r;
-                }
-                return hash;
-            }, {});
-        }
-    },
-    variable: function (name) {
-        return this.variables()[name];
-    },
-    rulesets: function () {
-        return this.rules.filter(function (r) {
-            return (r instanceof tree.Ruleset) || (r instanceof tree.mixin.Definition);
-        });
-    },
-    find: function (selector, self) {
-        self = self || this;
-        var rules = [], rule, match,
-            key = selector.toCSS();
-
-        if (key in this._lookups) { return this._lookups[key] }
-
-        this.rulesets().forEach(function (rule) {
-            if (rule !== self) {
-                for (var j = 0; j < rule.selectors.length; j++) {
-                    if (match = selector.match(rule.selectors[j])) {
-                        if (selector.elements.length > rule.selectors[j].elements.length) {
-                            Array.prototype.push.apply(rules, rule.find(
-                                new(tree.Selector)(selector.elements.slice(1)), self));
-                        } else {
-                            rules.push(rule);
-                        }
-                        break;
-                    }
-                }
-            }
-        });
-        return this._lookups[key] = rules;
-    },
-    //
-    // Entry point for code generation
-    //
-    //     `context` holds an array of arrays.
-    //
-    toCSS: function (context, env) {
-        var css = [],      // The CSS output
-            rules = [],    // node.Rule instances
-           _rules = [],    //
-            rulesets = [], // node.Ruleset instances
-            paths = [],    // Current selectors
-            selector,      // The fully rendered selector
-            debugInfo,     // Line number debugging
-            rule;
-
-        if (! this.root) {
-            this.joinSelectors(paths, context, this.selectors);
-        }
-
-        // Compile rules and rulesets
-        for (var i = 0; i < this.rules.length; i++) {
-            rule = this.rules[i];
-
-            if (rule.rules || (rule instanceof tree.Media)) {
-                rulesets.push(rule.toCSS(paths, env));
-            } else if (rule instanceof tree.Directive) {
-                var cssValue = rule.toCSS(paths, env);
-                // Output only the first @charset definition as such - convert the others
-                // to comments in case debug is enabled
-                if (rule.name === "@charset") {
-                    // Only output the debug info together with subsequent @charset definitions
-                    // a comment (or @media statement) before the actual @charset directive would
-                    // be considered illegal css as it has to be on the first line
-                    if (env.charset) {
-                        if (rule.debugInfo) {
-                            rulesets.push(tree.debugInfo(env, rule));
-                            rulesets.push(new tree.Comment("/* "+cssValue.replace(/\n/g, "")+" */\n").toCSS(env));
-                        }
-                        continue;
-                    }
-                    env.charset = true;
-                }
-                rulesets.push(cssValue);
-            } else if (rule instanceof tree.Comment) {
-                if (!rule.silent) {
-                    if (this.root) {
-                        rulesets.push(rule.toCSS(env));
-                    } else {
-                        rules.push(rule.toCSS(env));
-                    }
-                }
-            } else {
-                if (rule.toCSS && !rule.variable) {
-                    rules.push(rule.toCSS(env));
-                } else if (rule.value && !rule.variable) {
-                    rules.push(rule.value.toString());
-                }
-            }
-        }
-
-        // Remove last semicolon
-        if (env.compress && rules.length) {
-            rule = rules[rules.length - 1];
-            if (rule.charAt(rule.length - 1) === ';') {
-                rules[rules.length - 1] = rule.substring(0, rule.length - 1);
-            }
-        }
-
-        rulesets = rulesets.join('');
-
-        // If this is the root node, we don't render
-        // a selector, or {}.
-        // Otherwise, only output if this ruleset has rules.
-        if (this.root) {
-            css.push(rules.join(env.compress ? '' : '\n'));
-        } else {
-            if (rules.length > 0) {
-                debugInfo = tree.debugInfo(env, this);
-                selector = paths.map(function (p) {
-                    return p.map(function (s) {
-                        return s.toCSS(env);
-                    }).join('').trim();
-                }).join(env.compress ? ',' : ',\n');
-
-                // Remove duplicates
-                for (var i = rules.length - 1; i >= 0; i--) {
-                    if (_rules.indexOf(rules[i]) === -1) {
-                        _rules.unshift(rules[i]);
-                    }
-                }
-                rules = _rules;
-
-                css.push(debugInfo + selector +
-                        (env.compress ? '{' : ' {\n  ') +
-                        rules.join(env.compress ? '' : '\n  ') +
-                        (env.compress ? '}' : '\n}\n'));
-            }
-        }
-        css.push(rulesets);
-
-        return css.join('')  + (env.compress ? '\n' : '');
-    },
-
-    joinSelectors: function (paths, context, selectors) {
-        for (var s = 0; s < selectors.length; s++) {
-            this.joinSelector(paths, context, selectors[s]);
-        }
-    },
-
-    joinSelector: function (paths, context, selector) {
-
-        var i, j, k,
-            hasParentSelector, newSelectors, el, sel, parentSel,
-            newSelectorPath, afterParentJoin, newJoinedSelector,
-            newJoinedSelectorEmpty, lastSelector, currentElements,
-            selectorsMultiplied;
-
-        for (i = 0; i < selector.elements.length; i++) {
-            el = selector.elements[i];
-            if (el.value === '&') {
-                hasParentSelector = true;
-            }
-        }
-
-        if (!hasParentSelector) {
-            if (context.length > 0) {
-                for(i = 0; i < context.length; i++) {
-                    paths.push(context[i].concat(selector));
-                }
-            }
-            else {
-                paths.push([selector]);
-            }
-            return;
-        }
-
-        // The paths are [[Selector]]
-        // The first list is a list of comma seperated selectors
-        // The inner list is a list of inheritance seperated selectors
-        // e.g.
-        // .a, .b {
-        //   .c {
-        //   }
-        // }
-        // == [[.a] [.c]] [[.b] [.c]]
-        //
-
-        // the elements from the current selector so far
-        currentElements = [];
-        // the current list of new selectors to add to the path.
-        // We will build it up. We initiate it with one empty selector as we "multiply" the new selectors
-        // by the parents
-        newSelectors = [[]];
-
-        for (i = 0; i < selector.elements.length; i++) {
-            el = selector.elements[i];
-            // non parent reference elements just get added
-            if (el.value !== "&") {
-                currentElements.push(el);
-            } else {
-                // the new list of selectors to add
-                selectorsMultiplied = [];
-
-                // merge the current list of non parent selector elements
-                // on to the current list of selectors to add
-                if (currentElements.length > 0) {
-                    this.mergeElementsOnToSelectors(currentElements, newSelectors);
-                }
-
-                // loop through our current selectors
-                for(j = 0; j < newSelectors.length; j++) {
-                    sel = newSelectors[j];
-                    // if we don't have any parent paths, the & might be in a mixin so that it can be used
-                    // whether there are parents or not
-                    if (context.length == 0) {
-                        // the combinator used on el should now be applied to the next element instead so that
-                        // it is not lost
-                        if (sel.length > 0) {
-                            sel[0].elements = sel[0].elements.slice(0);
-                            sel[0].elements.push(new(tree.Element)(el.combinator, '', 0)); //new Element(el.Combinator,  ""));
-                        }
-                        selectorsMultiplied.push(sel);
-                    }
-                    else {
-                        // and the parent selectors
-                        for(k = 0; k < context.length; k++) {
-                            parentSel = context[k];
-                            // We need to put the current selectors
-                            // then join the last selector's elements on to the parents selectors
-
-                            // our new selector path
-                            newSelectorPath = [];
-                            // selectors from the parent after the join
-                            afterParentJoin = [];
-                            newJoinedSelectorEmpty = true;
-
-                            //construct the joined selector - if & is the first thing this will be empty,
-                            // if not newJoinedSelector will be the last set of elements in the selector
-                            if (sel.length > 0) {
-                                newSelectorPath = sel.slice(0);
-                                lastSelector = newSelectorPath.pop();
-                                newJoinedSelector = new(tree.Selector)(lastSelector.elements.slice(0));
-                                newJoinedSelectorEmpty = false;
-                            }
-                            else {
-                                newJoinedSelector = new(tree.Selector)([]);
-                            }
-
-                            //put together the parent selectors after the join
-                            if (parentSel.length > 1) {
-                                afterParentJoin = afterParentJoin.concat(parentSel.slice(1));
-                            }
-
-                            if (parentSel.length > 0) {
-                                newJoinedSelectorEmpty = false;
-
-                                // join the elements so far with the first part of the parent
-                                newJoinedSelector.elements.push(new(tree.Element)(el.combinator, parentSel[0].elements[0].value, 0));
-                                newJoinedSelector.elements = newJoinedSelector.elements.concat(parentSel[0].elements.slice(1));
-                            }
-
-                            if (!newJoinedSelectorEmpty) {
-                                // now add the joined selector
-                                newSelectorPath.push(newJoinedSelector);
-                            }
-
-                            // and the rest of the parent
-                            newSelectorPath = newSelectorPath.concat(afterParentJoin);
-
-                            // add that to our new set of selectors
-                            selectorsMultiplied.push(newSelectorPath);
-                        }
-                    }
-                }
-
-                // our new selectors has been multiplied, so reset the state
-                newSelectors = selectorsMultiplied;
-                currentElements = [];
-            }
-        }
-
-        // if we have any elements left over (e.g. .a& .b == .b)
-        // add them on to all the current selectors
-        if (currentElements.length > 0) {
-            this.mergeElementsOnToSelectors(currentElements, newSelectors);
-        }
-
-        for(i = 0; i < newSelectors.length; i++) {
-            if (newSelectors[i].length > 0) {
-                paths.push(newSelectors[i]);
-            }
-        }
-    },
-
-    mergeElementsOnToSelectors: function(elements, selectors) {
-        var i, sel;
-
-        if (selectors.length == 0) {
-            selectors.push([ new(tree.Selector)(elements) ]);
-            return;
-        }
-
-        for(i = 0; i < selectors.length; i++) {
-            sel = selectors[i];
-
-            // if the previous thing in sel is a parent this needs to join on to it
-            if (sel.length > 0) {
-                sel[sel.length - 1] = new(tree.Selector)(sel[sel.length - 1].elements.concat(elements));
-            }
-            else {
-                sel.push(new(tree.Selector)(elements));
-            }
-        }
-    }
-};
-})(require('../tree'));
-(function (tree) {
-
-tree.Selector = function (elements, extend) {
-    this.elements = elements;
-    this.extend = extend;
-};
-tree.Selector.prototype.match = function (other) {
-    var elements = this.elements,
-        len = elements.length,
-        oelements, olen, max, i;
-
-    oelements = other.elements.slice(
-        (other.elements.length && other.elements[0].value === "&") ? 1 : 0);
-    olen = oelements.length;
-    max = Math.min(len, olen)
-
-    if (olen === 0 || len < olen) {
-        return false;
-    } else {
-        for (i = 0; i < max; i++) {
-            if (elements[i].value !== oelements[i].value) {
-                return false;
-            }
-        }
-    }
-    return true;
-};
-tree.Selector.prototype.eval = function (env) {
-    return new(tree.Selector)(this.elements.map(function (e) {
-        return e.eval(env);
-    }), this.extend);
-};
-tree.Selector.prototype.toCSS = function (env) {
-    if (this._css) { return this._css }
-
-    if (this.elements[0].combinator.value === "") {
-        this._css = ' ';
-    } else {
-        this._css = '';
-    }
-
-    this._css += this.elements.map(function (e) {
-        if (typeof(e) === 'string') {
-            return ' ' + e.trim();
-        } else {
-            return e.toCSS(env);
-        }
-    }).join('');
-
-    return this._css;
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.UnicodeDescriptor = function (value) {
-    this.value = value;
-};
-tree.UnicodeDescriptor.prototype = {
-    toCSS: function (env) {
-        return this.value;
-    },
-    eval: function () { return this }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.URL = function (val, rootpath) {
-    this.value = val;
-    this.rootpath = rootpath;
-};
-tree.URL.prototype = {
-    toCSS: function () {
-        return "url(" + this.value.toCSS() + ")";
-    },
-    eval: function (ctx) {
-        var val = this.value.eval(ctx), rootpath;
-
-        // Add the base path if the URL is relative
-        if (this.rootpath && typeof val.value === "string" && ctx.isPathRelative(val.value)) {
-            rootpath = this.rootpath;
-            if (!val.quote) {
-                rootpath = rootpath.replace(/[\(\)'"\s]/g, function(match) { return "\\"+match; });
-            }
-            val.value = rootpath + val.value;
-        }
-
-        return new(tree.URL)(val, null);
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Value = function (value) {
-    this.value = value;
-    this.is = 'value';
-};
-tree.Value.prototype = {
-    eval: function (env) {
-        if (this.value.length === 1) {
-            return this.value[0].eval(env);
-        } else {
-            return new(tree.Value)(this.value.map(function (v) {
-                return v.eval(env);
-            }));
-        }
-    },
-    toCSS: function (env) {
-        return this.value.map(function (e) {
-            return e.toCSS(env);
-        }).join(env.compress ? ',' : ', ');
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.Variable = function (name, index, file) { this.name = name, this.index = index, this.file = file };
-tree.Variable.prototype = {
-    eval: function (env) {
-        var variable, v, name = this.name;
-
-        if (name.indexOf('@@') == 0) {
-            name = '@' + new(tree.Variable)(name.slice(1)).eval(env).value;
-        }
-
-        if (this.evaluating) {
-            throw { type: 'Name',
-                    message: "Recursive variable definition for " + name,
-                    filename: this.file,
-                    index: this.index };
-        }
-
-        this.evaluating = true;
-
-        if (variable = tree.find(env.frames, function (frame) {
-            if (v = frame.variable(name)) {
-                return v.value.eval(env);
-            }
-        })) {
-            this.evaluating = false;
-            return variable;
-        }
-        else {
-            throw { type: 'Name',
-                    message: "variable " + name + " is undefined",
-                    filename: this.file,
-                    index: this.index };
-        }
-    }
-};
-
-})(require('../tree'));
-(function (tree) {
-
-tree.debugInfo = function(env, ctx) {
-    var result="";
-    if (env.dumpLineNumbers && !env.compress) {
-        switch(env.dumpLineNumbers) {
-            case 'comments':
-                result = tree.debugInfo.asComment(ctx);
-                break;
-            case 'mediaquery':
-                result = tree.debugInfo.asMediaQuery(ctx);
-                break;
-            case 'all':
-                result = tree.debugInfo.asComment(ctx)+tree.debugInfo.asMediaQuery(ctx);
-                break;
-        }
-    }
-    return result;
-};
-
-tree.debugInfo.asComment = function(ctx) {
-    return '/* line ' + ctx.debugInfo.lineNumber + ', ' + ctx.debugInfo.fileName + ' */\n';
-};
-
-tree.debugInfo.asMediaQuery = function(ctx) {
-    return '@media -sass-debug-info{filename{font-family:' +
-        ('file://' + ctx.debugInfo.fileName).replace(/[\/:.]/g, '\\$&') +
-        '}line{font-family:\\00003' + ctx.debugInfo.lineNumber + '}}\n';
-};
-
-tree.find = function (obj, fun) {
-    for (var i = 0, r; i < obj.length; i++) {
-        if (r = fun.call(obj, obj[i])) { return r }
-    }
-    return null;
-};
-tree.jsify = function (obj) {
-    if (Array.isArray(obj.value) && (obj.value.length > 1)) {
-        return '[' + obj.value.map(function (v) { return v.toCSS(false) }).join(', ') + ']';
-    } else {
-        return obj.toCSS(false);
-    }
-};
-
-})(require('./tree'));
-(function (tree) {
-
-    var parseCopyProperties = [
-        'paths',            // paths to search for imports on
-        'optimization',     // option - optimization level (for the chunker)
-        'filename',         // current filename, used for error reporting
-        'files',            // list of files that have been imported, used for import-once
-        'contents',         // browser-only, contents of all the files
-        'rootpath',         // current rootpath to append to all url's
-        'relativeUrls',     // option - whether to adjust URL's to be relative
-        'strictImports',    // option -
-        'dumpLineNumbers',  // option - whether to dump line numbers
-        'compress',         // option - whether to compress
-        'mime',             // browser only - mime type for sheet import
-        'entryPath',        // browser only - path of entry less file
-        'rootFilename',     // browser only - href of the entry less file
-        'currentDirectory'  // node only - the current directory
-    ];
-
-    tree.parseEnv = function(options) {
-        copyFromOriginal(options, this, parseCopyProperties);
-
-        if (!this.contents) { this.contents = {}; }
-        if (!this.rootpath) { this.rootpath = ''; }
-        if (!this.files) { this.files = {}; }
-    };
-
-    tree.parseEnv.prototype.toSheet = function (path) {
-        var env = new tree.parseEnv(this);
-        env.href = path;
-        //env.title = path;
-        env.type = this.mime;
-        return env;
-    };
-
-    var evalCopyProperties = [
-        'silent',      // whether to swallow errors and warnings
-        'verbose',     // whether to log more activity
-        'compress',    // whether to compress
-        'ieCompat',    // whether to enforce IE compatibility (IE8 data-uri)
-        'strictMaths', // whether maths has to be within parenthesis
-        'strictUnits'  // whether units need to evaluate correctly
-        ];
-
-    tree.evalEnv = function(options, frames) {
-        copyFromOriginal(options, this, evalCopyProperties);
-
-        this.frames = frames || [];
-    };
-
-    tree.evalEnv.prototype.inParenthesis = function () {
-        if (!this.parensStack) {
-            this.parensStack = [];
-        }
-        this.parensStack.push(true);
-    };
-
-    tree.evalEnv.prototype.outOfParenthesis = function () {
-        this.parensStack.pop();
-    };
-
-    tree.evalEnv.prototype.isMathsOn = function () {
-        return this.strictMaths === false ? true : (this.parensStack && this.parensStack.length);
-    };
-
-    tree.evalEnv.prototype.isPathRelative = function (path) {
-        return !/^(?:[a-z-]+:|\/)/.test(path);
-    };
-
-    //todo - do the same for the toCSS env
-    //tree.toCSSEnv = function (options) {
-    //};
-
-    var copyFromOriginal = function(original, destination, propertiesToCopy) {
-        if (!original) { return; }
-
-        for(var i = 0; i < propertiesToCopy.length; i++) {
-            if (original.hasOwnProperty(propertiesToCopy[i])) {
-                destination[propertiesToCopy[i]] = original[propertiesToCopy[i]];
-            }
-        }
-    }
-})(require('./tree'));//
-// browser.js - client-side engine
-//
-
-var isFileProtocol = /^(file|chrome(-extension)?|resource|qrc|app):/.test(location.protocol);
-
-less.env = less.env || (location.hostname == '127.0.0.1' ||
-                        location.hostname == '0.0.0.0'   ||
-                        location.hostname == 'localhost' ||
-                        location.port.length > 0         ||
-                        isFileProtocol                   ? 'development'
-                                                         : 'production');
-
-// Load styles asynchronously (default: false)
-//
-// This is set to `false` by default, so that the body
-// doesn't start loading before the stylesheets are parsed.
-// Setting this to `true` can result in flickering.
-//
-less.async = less.async || false;
-less.fileAsync = less.fileAsync || false;
-
-// Interval between watch polls
-less.poll = less.poll || (isFileProtocol ? 1000 : 1500);
-
-//Setup user functions
-if (less.functions) {
-    for(var func in less.functions) {
-        less.tree.functions[func] = less.functions[func];
-   }
-}
-
-var dumpLineNumbers = /!dumpLineNumbers:(comments|mediaquery|all)/.exec(location.hash);
-if (dumpLineNumbers) {
-    less.dumpLineNumbers = dumpLineNumbers[1];
-}
-
-//
-// Watch mode
-//
-less.watch   = function () {
-    if (!less.watchMode ){
-        less.env = 'development';
-         initRunningMode();
-    }
-    return this.watchMode = true
-};
-
-less.unwatch = function () {clearInterval(less.watchTimer); return this.watchMode = false; };
-
-function initRunningMode(){
-    if (less.env === 'development') {
-        less.optimization = 0;
-        less.watchTimer = setInterval(function () {
-            if (less.watchMode) {
-                loadStyleSheets(function (e, root, _, sheet, env) {
-                    if (e) {
-                        error(e, sheet.href);
-                    } else if (root) {
-                        createCSS(root.toCSS(less), sheet, env.lastModified);
-                    }
-                });
-            }
-        }, less.poll);
-    } else {
-        less.optimization = 3;
-    }
-}
-
-if (/!watch/.test(location.hash)) {
-    less.watch();
-}
-
-var cache = null;
-
-if (less.env != 'development') {
-    try {
-        cache = (typeof(window.localStorage) === 'undefined') ? null : window.localStorage;
-    } catch (_) {}
-}
-
-//
-// Get all <link> tags with the 'rel' attribute set to "stylesheet/less"
-//
-var links = document.getElementsByTagName('link');
-var typePattern = /^text\/(x-)?less$/;
-
-less.sheets = [];
-
-for (var i = 0; i < links.length; i++) {
-    if (links[i].rel === 'stylesheet/less' || (links[i].rel.match(/stylesheet/) &&
-       (links[i].type.match(typePattern)))) {
-        less.sheets.push(links[i]);
-    }
-}
-
-//
-// With this function, it's possible to alter variables and re-render
-// CSS without reloading less-files
-//
-var session_cache = '';
-less.modifyVars = function(record) {
-    var str = session_cache;
-    for (name in record) {
-        str += ((name.slice(0,1) === '@')? '' : '@') + name +': '+
-                ((record[name].slice(-1) === ';')? record[name] : record[name] +';');
-    }
-    new(less.Parser)(new less.tree.parseEnv(less)).parse(str, function (e, root) {
-        if (e) {
-            error(e, "session_cache");
-        } else {
-            createCSS(root.toCSS(less), less.sheets[less.sheets.length - 1]);
-        }
-    });
-};
-
-less.refresh = function (reload) {
-    var startTime, endTime;
-    startTime = endTime = new(Date);
-
-    loadStyleSheets(function (e, root, _, sheet, env) {
-        if (e) {
-            return error(e, sheet.href);
-        }
-        if (env.local) {
-            log("loading " + sheet.href + " from cache.");
-        } else {
-            log("parsed " + sheet.href + " successfully.");
-            createCSS(root.toCSS(less), sheet, env.lastModified);
-        }
-        log("css for " + sheet.href + " generated in " + (new(Date) - endTime) + 'ms');
-        (env.remaining === 0) && log("css generated in " + (new(Date) - startTime) + 'ms');
-        endTime = new(Date);
-    }, reload);
-
-    loadStyles();
-};
-less.refreshStyles = loadStyles;
-
-less.refresh(less.env === 'development');
-
-function loadStyles() {
-    var styles = document.getElementsByTagName('style');
-    for (var i = 0; i < styles.length; i++) {
-        if (styles[i].type.match(typePattern)) {
-            var env = new less.tree.parseEnv(less);
-            env.filename = document.location.href.replace(/#.*$/, '');
-
-            new(less.Parser)(env).parse(styles[i].innerHTML || '', function (e, cssAST) {
-                if (e) {
-                    return error(e, "inline");
-                }
-                var css = cssAST.toCSS(less);
-                var style = styles[i];
-                style.type = 'text/css';
-                if (style.styleSheet) {
-                    style.styleSheet.cssText = css;
-                } else {
-                    style.innerHTML = css;
-                }
-            });
-        }
-    }
-}
-
-function loadStyleSheets(callback, reload) {
-    for (var i = 0; i < less.sheets.length; i++) {
-        loadStyleSheet(less.sheets[i], callback, reload, less.sheets.length - (i + 1));
-    }
-}
-
-function pathDiff(url, baseUrl) {
-    // diff between two paths to create a relative path
-
-    var urlParts = extractUrlParts(url),
-        baseUrlParts = extractUrlParts(baseUrl),
-        i, max, urlDirectories, baseUrlDirectories, diff = "";
-    if (urlParts.hostPart !== baseUrlParts.hostPart) {
-        return "";
-    }
-    max = Math.max(baseUrlParts.directories.length, urlParts.directories.length);
-    for(i = 0; i < max; i++) {
-        if (baseUrlParts.directories[i] !== urlParts.directories[i]) { break; }
-    }
-    baseUrlDirectories = baseUrlParts.directories.slice(i);
-    urlDirectories = urlParts.directories.slice(i);
-    for(i = 0; i < baseUrlDirectories.length-1; i++) {
-        diff += "../";
-    }
-    for(i = 0; i < urlDirectories.length-1; i++) {
-        diff += urlDirectories[i] + "/";
-    }
-    return diff;
-}
-
-function extractUrlParts(url, baseUrl) {
-    // urlParts[1] = protocol&hostname || /
-    // urlParts[2] = / if path relative to host base
-    // urlParts[3] = directories
-    // urlParts[4] = filename
-    // urlParts[5] = parameters
-
-    var urlPartsRegex = /^((?:[a-z-]+:)?\/+?(?:[^\/\?#]*\/)|([\/\\]))?((?:[^\/\\\?#]*[\/\\])*)([^\/\\\?#]*)([#\?].*)?$/,
-        urlParts = url.match(urlPartsRegex),
-        returner = {}, directories = [], i, baseUrlParts;
-
-    if (!urlParts) {
-        throw new Error("Could not parse sheet href - '"+url+"'");
-    }
-
-    // Stylesheets in IE don't always return the full path
-    if (!urlParts[1] || urlParts[2]) {
-        baseUrlParts = baseUrl.match(urlPartsRegex);
-        if (!baseUrlParts) {
-            throw new Error("Could not parse page url - '"+baseUrl+"'");
-        }
-        urlParts[1] = baseUrlParts[1];
-        if (!urlParts[2]) {
-            urlParts[3] = baseUrlParts[3] + urlParts[3];
-        }
-    }
-
-    if (urlParts[3]) {
-        directories = urlParts[3].replace("\\", "/").split("/");
-
-        for(i = 0; i < directories.length; i++) {
-            if (directories[i] === ".." && i > 0) {
-                directories.splice(i-1, 2);
-                i -= 2;
-            }
-        }
-    }
-
-    returner.hostPart = urlParts[1];
-    returner.directories = directories;
-    returner.path = urlParts[1] + directories.join("/");
-    returner.fileUrl = returner.path + (urlParts[4] || "");
-    returner.url = returner.fileUrl + (urlParts[5] || "");
-    return returner;
-}
-
-function loadStyleSheet(sheet, callback, reload, remaining) {
-
-    // sheet may be set to the stylesheet for the initial load or a collection of properties including
-    // some env variables for imports
-    var hrefParts = extractUrlParts(sheet.href, window.location.href);
-    var href      = hrefParts.url;
-    var css       = cache && cache.getItem(href);
-    var timestamp = cache && cache.getItem(href + ':timestamp');
-    var styles    = { css: css, timestamp: timestamp };
-    var env;
-
-    if (sheet instanceof less.tree.parseEnv) {
-        env = new less.tree.parseEnv(sheet);
-    } else {
-        env = new less.tree.parseEnv(less);
-        env.entryPath = hrefParts.path;
-        env.mime = sheet.type;
-    }
-
-    if (env.relativeUrls) {
-        //todo - this relies on option being set on less object rather than being passed in as an option
-        //     - need an originalRootpath
-        if (less.rootpath) {
-            env.rootpath = extractUrlParts(less.rootpath + pathDiff(hrefParts.path, env.entryPath)).path;
-        } else {
-            env.rootpath = hrefParts.path;
-        }
-    } else  {
-        if (!less.rootpath) {
-            env.rootpath = env.entryPath;
-        }
-    }
-
-    xhr(href, sheet.type, function (data, lastModified) {
-        // Store data this session
-        session_cache += data.replace(/@import .+?;/ig, '');
-
-        if (!reload && styles && lastModified &&
-           (new(Date)(lastModified).valueOf() ===
-            new(Date)(styles.timestamp).valueOf())) {
-            // Use local copy
-            createCSS(styles.css, sheet);
-            callback(null, null, data, sheet, { local: true, remaining: remaining }, href);
-        } else {
-            // Use remote copy (re-parse)
-            try {
-                env.contents[href] = data;  // Updating content cache
-                env.paths = [hrefParts.path];
-                env.filename = href;
-                env.rootFilename = env.rootFilename || href;
-                new(less.Parser)(env).parse(data, function (e, root) {
-                    if (e) { return callback(e, null, null, sheet); }
-                    try {
-                        callback(e, root, data, sheet, { local: false, lastModified: lastModified, remaining: remaining }, href);
-                        //TODO - there must be a better way? A generic less-to-css function that can both call error
-                        //and removeNode where appropriate
-                        //should also add tests
-                        if (env.rootFilename === href) {
-                            removeNode(document.getElementById('less-error-message:' + extractId(href)));
-                        }
-                    } catch (e) {
-                        callback(e, null, null, sheet);
-                    }
-                });
-            } catch (e) {
-                callback(e, null, null, sheet);
-            }
-        }
-    }, function (status, url) {
-        callback({ type: 'File', message: "'" + url + "' wasn't found (" + status + ")" }, null, null, sheet);
-    });
-}
-
-function extractId(href) {
-    return href.replace(/^[a-z-]+:\/+?[^\/]+/, '' )  // Remove protocol & domain
-               .replace(/^\//,                 '' )  // Remove root /
-               .replace(/\.[a-zA-Z]+$/,        '' )  // Remove simple extension
-               .replace(/[^\.\w-]+/g,          '-')  // Replace illegal characters
-               .replace(/\./g,                 ':'); // Replace dots with colons(for valid id)
-}
-
-function createCSS(styles, sheet, lastModified) {
-    // Strip the query-string
-    var href = sheet.href || '';
-
-    // If there is no title set, use the filename, minus the extension
-    var id = 'less:' + (sheet.title || extractId(href));
-
-    // If this has already been inserted into the DOM, we may need to replace it
-    var oldCss = document.getElementById(id);
-    var keepOldCss = false;
-
-    // Create a new stylesheet node for insertion or (if necessary) replacement
-    var css = document.createElement('style');
-    css.setAttribute('type', 'text/css');
-    if (sheet.media) {
-        css.setAttribute('media', sheet.media);
-    }
-    css.id = id;
-
-    if (css.styleSheet) { // IE
-        try {
-            css.styleSheet.cssText = styles;
-        } catch (e) {
-            throw new(Error)("Couldn't reassign styleSheet.cssText.");
-        }
-    } else {
-        css.appendChild(document.createTextNode(styles));
-
-        // If new contents match contents of oldCss, don't replace oldCss
-        keepOldCss = (oldCss !== null && oldCss.childNodes.length > 0 && css.childNodes.length > 0 &&
-            oldCss.firstChild.nodeValue === css.firstChild.nodeValue);
-    }
-
-    var head = document.getElementsByTagName('head')[0];
-
-    // If there is no oldCss, just append; otherwise, only append if we need
-    // to replace oldCss with an updated stylesheet
-    if (oldCss == null || keepOldCss === false) {
-        var nextEl = sheet && sheet.nextSibling || null;
-        (nextEl || document.getElementsByTagName('head')[0]).parentNode.insertBefore(css, nextEl);
-    }
-    if (oldCss && keepOldCss === false) {
-        head.removeChild(oldCss);
-    }
-
-    // Don't update the local store if the file wasn't modified
-    if (lastModified && cache) {
-        log('saving ' + href + ' to cache.');
-        try {
-            cache.setItem(href, styles);
-            cache.setItem(href + ':timestamp', lastModified);
-        } catch(e) {
-            //TODO - could do with adding more robust error handling
-            log('failed to save');
-        }
-    }
-}
-
-function xhr(url, type, callback, errback) {
-    var xhr = getXMLHttpRequest();
-    var async = isFileProtocol ? less.fileAsync : less.async;
-
-    if (typeof(xhr.overrideMimeType) === 'function') {
-        xhr.overrideMimeType('text/css');
-    }
-    xhr.open('GET', url, async);
-    xhr.setRequestHeader('Accept', type || 'text/x-less, text/css; q=0.9, */*; q=0.5');
-    xhr.send(null);
-
-    if (isFileProtocol && !less.fileAsync) {
-        if (xhr.status === 0 || (xhr.status >= 200 && xhr.status < 300)) {
-            callback(xhr.responseText);
-        } else {
-            errback(xhr.status, url);
-        }
-    } else if (async) {
-        xhr.onreadystatechange = function () {
-            if (xhr.readyState == 4) {
-                handleResponse(xhr, callback, errback);
-            }
-        };
-    } else {
-        handleResponse(xhr, callback, errback);
-    }
-
-    function handleResponse(xhr, callback, errback) {
-        if (xhr.status >= 200 && xhr.status < 300) {
-            callback(xhr.responseText,
-                     xhr.getResponseHeader("Last-Modified"));
-        } else if (typeof(errback) === 'function') {
-            errback(xhr.status, url);
-        }
-    }
-}
-
-function getXMLHttpRequest() {
-    if (window.XMLHttpRequest) {
-        return new(XMLHttpRequest);
-    } else {
-        try {
-            return new(ActiveXObject)("MSXML2.XMLHTTP.3.0");
-        } catch (e) {
-            log("browser doesn't support AJAX.");
-            return null;
-        }
-    }
-}
-
-function removeNode(node) {
-    return node && node.parentNode.removeChild(node);
-}
-
-function log(str) {
-    if (less.env == 'development' && typeof(console) !== "undefined") { console.log('less: ' + str) }
-}
-
-function error(e, rootHref) {
-    var id = 'less-error-message:' + extractId(rootHref || "");
-    var template = '<li><label>{line}</label><pre class="{class}">{content}</pre></li>';
-    var elem = document.createElement('div'), timer, content, error = [];
-    var filename = e.filename || rootHref;
-    var filenameNoPath = filename.match(/([^\/]+(\?.*)?)$/)[1];
-
-    elem.id        = id;
-    elem.className = "less-error-message";
-
-    content = '<h3>'  + (e.type || "Syntax") + "Error: " + (e.message || 'There is an error in your .less file') +
-              '</h3>' + '<p>in <a href="' + filename   + '">' + filenameNoPath + "</a> ";
-
-    var errorline = function (e, i, classname) {
-        if (e.extract[i] != undefined) {
-            error.push(template.replace(/\{line\}/, (parseInt(e.line) || 0) + (i - 1))
-                               .replace(/\{class\}/, classname)
-                               .replace(/\{content\}/, e.extract[i]));
-        }
-    };
-
-    if (e.extract) {
-        errorline(e, 0, '');
-        errorline(e, 1, 'line');
-        errorline(e, 2, '');
-        content += 'on line ' + e.line + ', column ' + (e.column + 1) + ':</p>' +
-                    '<ul>' + error.join('') + '</ul>';
-    } else if (e.stack) {
-        content += '<br/>' + e.stack.split('\n').slice(1).join('<br/>');
-    }
-    elem.innerHTML = content;
-
-    // CSS for error messages
-    createCSS([
-        '.less-error-message ul, .less-error-message li {',
-            'list-style-type: none;',
-            'margin-right: 15px;',
-            'padding: 4px 0;',
-            'margin: 0;',
-        '}',
-        '.less-error-message label {',
-            'font-size: 12px;',
-            'margin-right: 15px;',
-            'padding: 4px 0;',
-            'color: #cc7777;',
-        '}',
-        '.less-error-message pre {',
-            'color: #dd6666;',
-            'padding: 4px 0;',
-            'margin: 0;',
-            'display: inline-block;',
-        '}',
-        '.less-error-message pre.line {',
-            'color: #ff0000;',
-        '}',
-        '.less-error-message h3 {',
-            'font-size: 20px;',
-            'font-weight: bold;',
-            'padding: 15px 0 5px 0;',
-            'margin: 0;',
-        '}',
-        '.less-error-message a {',
-            'color: #10a',
-        '}',
-        '.less-error-message .error {',
-            'color: red;',
-            'font-weight: bold;',
-            'padding-bottom: 2px;',
-            'border-bottom: 1px dashed red;',
-        '}'
-    ].join('\n'), { title: 'error-message' });
-
-    elem.style.cssText = [
-        "font-family: Arial, sans-serif",
-        "border: 1px solid #e00",
-        "background-color: #eee",
-        "border-radius: 5px",
-        "-webkit-border-radius: 5px",
-        "-moz-border-radius: 5px",
-        "color: #e00",
-        "padding: 15px",
-        "margin-bottom: 15px"
-    ].join(';');
-
-    if (less.env == 'development') {
-        timer = setInterval(function () {
-            if (document.body) {
-                if (document.getElementById(id)) {
-                    document.body.replaceChild(elem, document.getElementById(id));
-                } else {
-                    document.body.insertBefore(elem, document.body.firstChild);
-                }
-                clearInterval(timer);
-            }
-        }, 10);
-    }
-}
-// amd.js
-//
-// Define Less as an AMD module.
-if (typeof define === "function" && define.amd) {
-    define(function () { return less; } );
-}
-})(window);
\ No newline at end of file