fix GW-2603

src/client/styles/scss/theme/_apply-colors.scss

@@ -154,6 +154,11 @@ pre:not(.hljs):not(.CodeMirror-line) {
   .btn-secondary.dropdown-toggle {
     @include button-variant($bgcolor-search-top-dropdown, $bgcolor-search-top-dropdown);
   }
+
+  // for https://youtrack.weseek.co.jp/issue/GW-2603
+  .search-typeahead {
+    background-color: rgba($bgcolor-global, 0.9);
+  }
 }
 
 .grw-sidebar {