Fix search results styling to show dark background for all items

- Add default dark background (#374151) to all search result items
- Update hover/selected state to slightly lighter background (#4b5563)
- Ensure consistent dark theme styling across all search results
- Fix issue where only first result had proper dark background

This ensures all search results have proper visibility and consistent styling with the dark theme.

Author: mich-elle-luna

layouts/partials/search-modal.html

@@ -19,12 +19,13 @@
     padding: 0.75rem;
     display: block;
     border-radius: 0.375rem;
+    background-color: #374151;
     transition: background-color 0.2s;
   }
 
   .search-item a:hover,
   .search-item[aria-selected] a {
-    background-color: #374151;
+    background-color: #4b5563;
     color: white;
   }