fix nav bar position

hbd/server/templates/head.html

@@ -15,6 +15,7 @@
       body {
         margin: 0;
         padding: 10px;
+        padding-top: 60px;
         background: #f5f5f5;
       }
       h1 { font-size: 1.5em; color: #333; margin: 0 0 5px; }
@@ -23,11 +24,14 @@
 
       /* Navigation bar — shared across all pages */
       .nav {
+        position: fixed;
+        top: 0;
+        left: 0;
+        right: 0;
+        z-index: 200;
         background: #fff;
         padding: 6px 12px;
-        margin-bottom: 10px;
         box-shadow: 0 2px 4px rgba(0,0,0,.1);
-        border-radius: 4px;
         display: flex;
         align-items: center;
         justify-content: space-between;

hbd/server/templates/settings.html

@@ -23,7 +23,7 @@
       width: 180px;
       flex-shrink: 0;
       position: sticky;
-      top: 20px;
+      top: 60px;
     }
 
     .sidebar-nav a {