Fix margin of elements in flex

default_app/index.html

@@ -17,6 +17,10 @@
       flex-direction: column;
     }
 
+    .container > * {
+      margin: 15px 0 0 0;
+    }
+
     .header {
       background-color: #2f3241;
       border-bottom: 1px solid #1a1b23;