Reduction

frontend/app/assets/css/shared.scss

@@ -1,17 +1,13 @@
-// Shared TUI transition mixin
-@mixin tui-transition($steps: 2) {
-  transition: all 0.1s steps($steps, end);
-}
+/* Global rules shared across pages/components (imported once via nuxt.config css). */
 
-// Box-drawing content string for borders (top/bottom frame lines)
-$box-line-top: "═══════════════════";
-
-/* Global rules - no-sprite pages hide the undertable sprite area */
-.no-sprite .undertable-wrapper {
+/* Pages that opt out of the header sprite hide the TableHeader undertable area.
+   Selector is prefixed with the element type so it always outranks TableHeader's
+   scoped `.undertable-wrapper { display: flex }` regardless of stylesheet order. */
+div.no-sprite .undertable-wrapper {
   display: none;
 }
 
-// Dropdown transition keyframes (used by LanguageSelector and ThemeSelector)
+/* Dropdown transition (used by LanguageSelector and ThemeSelector). */
 .dropdown-enter-active, .dropdown-leave-active {
   transition: opacity 0.2s ease, transform 0.2s ease;
 }
@@ -19,14 +15,3 @@ $box-line-top: "═══════════════════";
   opacity: 0;
   transform: translateY(-8px);
 }
-
-// Dropdown button shared styles
-.tui-dropdown-button {
-  background: var(--color-background-fore);
-  color: var(--color-text);
-  font-size: 1em;
-  border: 1px solid var(--color-border-color);
-  padding: 8px 12px;
-  border-radius: 0;
-  cursor: pointer;
-}