diff --git a/inst/www/shared/selectize/scss/plugins/auto_position.scss b/inst/www/shared/selectize/scss/plugins/auto_position.scss
index 89c5cf008..01bd45cf6 100644
--- a/inst/www/shared/selectize/scss/plugins/auto_position.scss
+++ b/inst/www/shared/selectize/scss/plugins/auto_position.scss
@@ -2,7 +2,7 @@
   border-top: 1px solid $select-color-border;
   border-bottom: 0 none;
   border-radius: 3px 3px 0 0;
-  box-shadow: 0 -6px 12px rgb(0 0 0 / 18%);
+  box-shadow: 0 -6px 12px rgba(var(--bs-body-color-rgb, 0,0,0), .18);
 }
 
 .#{selectize}-control.plugin-auto_position .#{selectize}-input.#{$selectize}-position-top.dropdown-active {
diff --git a/inst/www/shared/selectize/scss/plugins/clear_button.scss b/inst/www/shared/selectize/scss/plugins/clear_button.scss
index 4f0d1d815..566ffd281 100644
--- a/inst/www/shared/selectize/scss/plugins/clear_button.scss
+++ b/inst/www/shared/selectize/scss/plugins/clear_button.scss
@@ -7,7 +7,7 @@
         width: 25px;
         top: 0;
         right: calc(#{$select-padding-x} - #{$select-padding-item-x});
-        color: rgba(0, 0, 0);
+        color: var(--bs-body-color, black);
         opacity: 0.4;
         font-weight: bold;
         border: none;
diff --git a/inst/www/shared/selectize/scss/selectize.scss b/inst/www/shared/selectize/scss/selectize.scss
index aec43bb43..30619ba9b 100644
--- a/inst/www/shared/selectize/scss/selectize.scss
+++ b/inst/www/shared/selectize/scss/selectize.scss
@@ -346,7 +346,7 @@ $select-spinner-border-color: $select-color-border;
     position: absolute;
     top: 50%;
     right: $select-arrow-offset;
-    margin-top: round(math.div(-1 * $select-arrow-size, 2));
+    margin-top: round(divide(-1 * $select-arrow-size, 2));
     width: 0;
     height: 0;
     border-style: solid;
