Complete dropdown z-index fix with proper stacking context

- Add z-index: 9999 to header and nav elements
- Ensure proper stacking context with position: relative
- Fix dropdown rendering underneath H1 and body text
- Comprehensive solution for all dropdown layering issues

templates/base.html

@@ -64,12 +64,24 @@
                 transition: width 0.1s ease-out;
             }
 
+            /* Header and nav z-index for dropdown stacking */
+            header {
+                position: relative;
+                z-index: 9999;
+            }
+            
+            nav {
+                position: relative;
+                z-index: 9999;
+            }
+
             /* Dropdown navigation styles */
             .nav-dropdown {
                 position: relative;
                 display: inline-block;
                 padding: 0.5rem;
                 margin: -0.5rem;
+                z-index: 9999;
             }