feature: AppBar clearance & Theming

DeepDrftPublic.Client/Layout/DeepDrftMenu.razor.css

@@ -16,7 +16,12 @@
     justify-content: space-between;
     gap: 2rem;
 
-    padding: 1.5rem 3rem;
+    /* Height is pinned to the shared --deepdrft-nav-height token so the main-content
+       clearance (.dd-main-content) always matches the bar exactly. Contents stay
+       vertically centred via align-items; horizontal padding only here. */
+    height: var(--deepdrft-nav-height);
+    box-sizing: border-box;
+    padding: 0 3rem;
 
     border-bottom: 1px solid var(--deepdrft-border);
     box-shadow: none;
@@ -226,6 +231,6 @@
 /* Mobile padding — give the nav room to breathe without crowding */
 @media (max-width: 599px) {
     .dd-nav {
-        padding: 1rem 1.25rem;
+        padding: 0 1.25rem;
     }
 }

DeepDrftPublic.Client/Layout/MainLayout.razor

@@ -15,7 +15,7 @@
     <MudLayout Style="display: flex; flex-direction: column; min-height: 100vh">
         <AudioPlayerProvider>
             <DeepDrftMenu Elevation="4" @bind-IsDarkMode="_isDarkMode" />
-            <MudMainContent Class="flex-grow-1 pt-16 pb-8">
+            <MudMainContent Class="flex-grow-1 pb-8 dd-main-content">
                 <MudContainer MaxWidth="MaxWidth.False" Class="pa-4">
                     @Body
                 </MudContainer>