Replace random HSL gradients in homepage cards with header-style gradient; header keeps its own CSS-variables gradient

templates/header.php

@@ -55,8 +55,11 @@ $_thesisId     = $_GET['id'] ?? null;
         </ul>
     </nav>
 
+</header>
+
+<?php if (!$_isAdmin): ?>
 <?php
-    // Search bar — public section only
+// Search bar — public section only (rendered below header for equal height)
 $searchBarValue = $searchBarValue ?? $_GET['query'] ?? '';
 ?>
 <div class="header-search-wrap">
@@ -78,7 +81,4 @@ $_thesisId     = $_GET['id'] ?? null;
         >
     </form>
 </div>
-
 <?php endif; ?>
-
-</header>