Add tablet navigation drawer to shell

src/RolemasterDb.App/Components/Shell/AppShell.razor

@@ -1,3 +1,6 @@
+@implements IDisposable
+@inject NavigationManager NavigationManager
+
 <div class="app-shell">
     <a class="skip-link" href="#app-main">Skip to main content</a>
 
@@ -39,6 +42,17 @@
             </div>
 
             <div class="app-shell-header-actions">
+                <button
+                    type="button"
+                    class="app-shell-menu-toggle"
+                    aria-expanded="@isNavMenuOpen"
+                    aria-controls="app-shell-drawer"
+                    @onclick="ToggleNavMenu">
+                    <span class="app-shell-menu-toggle-bar"></span>
+                    <span class="app-shell-menu-toggle-bar"></span>
+                    <span class="app-shell-menu-toggle-bar"></span>
+                    <span class="visually-hidden">Toggle navigation</span>
+                </button>
                 @UtilityContent
             </div>
         </div>
@@ -57,6 +71,26 @@
         </div>
     </main>
 
+    @if (isNavMenuOpen)
+    {
+        <button
+            type="button"
+            class="app-shell-drawer-backdrop"
+            aria-label="Close navigation"
+            @onclick="CloseNavMenu"></button>
+
+        <aside id="app-shell-drawer" class="app-shell-drawer" aria-label="Primary navigation">
+            <div class="app-shell-drawer-header">
+                <strong>Navigate</strong>
+                <button type="button" class="app-shell-drawer-close" @onclick="CloseNavMenu">
+                    Close
+                </button>
+            </div>
+
+            <ShellPrimaryNav />
+        </aside>
+    }
+
     <nav class="app-shell-mobile-nav" aria-label="Primary">
         <ShellPrimaryNav IsBottomNav="true" />
     </nav>
@@ -80,4 +114,32 @@
 
     [Parameter]
     public RenderFragment? UtilityContent { get; set; }
+
+    private bool isNavMenuOpen;
+
+    protected override void OnInitialized()
+    {
+        NavigationManager.LocationChanged += HandleLocationChanged;
+    }
+
+    private void ToggleNavMenu()
+    {
+        isNavMenuOpen = !isNavMenuOpen;
+    }
+
+    private void CloseNavMenu()
+    {
+        isNavMenuOpen = false;
+    }
+
+    private void HandleLocationChanged(object? sender, LocationChangedEventArgs args)
+    {
+        isNavMenuOpen = false;
+        _ = InvokeAsync(StateHasChanged);
+    }
+
+    public void Dispose()
+    {
+        NavigationManager.LocationChanged -= HandleLocationChanged;
+    }
 }

src/RolemasterDb.App/Components/Shell/AppShell.razor.css

@@ -103,6 +103,28 @@
     min-height: 2.75rem;
 }
 
+.app-shell-menu-toggle {
+    display: none;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 0.24rem;
+    width: 2.75rem;
+    height: 2.75rem;
+    border: 1px solid var(--border-default);
+    border-radius: 16px;
+    background: color-mix(in srgb, var(--surface-2) 84%, transparent);
+    color: var(--text-primary);
+    padding: 0;
+}
+
+.app-shell-menu-toggle-bar {
+    width: 1rem;
+    height: 2px;
+    border-radius: 999px;
+    background: currentColor;
+}
+
 .app-shell-shortcuts {
     margin-top: 0.75rem;
 }
@@ -128,6 +150,55 @@
     margin-top: auto;
 }
 
+.app-shell-drawer-backdrop {
+    position: fixed;
+    inset: 0;
+    z-index: 45;
+    border: none;
+    background: var(--bg-overlay);
+    padding: 0;
+}
+
+.app-shell-drawer {
+    position: fixed;
+    top: 1rem;
+    right: 1rem;
+    z-index: 50;
+    width: min(24rem, calc(100vw - 2rem));
+    padding: 1rem;
+    border: 1px solid var(--border-default);
+    border-radius: 24px;
+    background: color-mix(in srgb, var(--bg-elevated) 94%, transparent);
+    box-shadow: var(--shadow-2);
+    backdrop-filter: blur(18px);
+}
+
+.app-shell-drawer .shell-primary-nav {
+    flex-direction: column;
+    align-items: stretch;
+}
+
+.app-shell-drawer .shell-primary-nav-link {
+    justify-content: flex-start;
+}
+
+.app-shell-drawer-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 0.75rem;
+    margin-bottom: 0.75rem;
+}
+
+.app-shell-drawer-close {
+    border: 1px solid var(--border-default);
+    border-radius: 999px;
+    background: color-mix(in srgb, var(--surface-2) 84%, transparent);
+    color: var(--text-primary);
+    min-height: 2.5rem;
+    padding: 0.45rem 0.85rem;
+}
+
 @media (max-width: 767.98px) {
     .app-shell-header {
         padding: 0.65rem 0.75rem 0;
@@ -170,4 +241,15 @@
     .app-shell-header-nav {
         display: none;
     }
+
+    .app-shell-menu-toggle {
+        display: inline-flex;
+    }
+}
+
+@media (min-width: 1024px) {
+    .app-shell-drawer,
+    .app-shell-drawer-backdrop {
+        display: none;
+    }
 }