diff --git a/wwwroot/shell_theme.css b/wwwroot/shell_theme.css
index 9215966..6d5cdd9 100644
--- a/wwwroot/shell_theme.css
+++ b/wwwroot/shell_theme.css
@@ -128,7 +128,9 @@ body {
   overflow-y: auto;
   overflow-x: hidden;
   flex-shrink: 0;
-  transition: width 0.25s ease;
+  transition: width 0.3s ease, transform 0.3s ease;
+  position: relative;
+  z-index: 50;
 }
 
 .sage-sidebar.collapsed {
@@ -141,12 +143,48 @@ body {
   overflow: hidden;
 }
 
+/* Mobile: sidebar as overlay */
+@media (max-width: 768px) {
+  .sage-sidebar {
+    position: fixed;
+    left: 0;
+    top: var(--sage-topbar-height);
+    height: calc(100vh - var(--sage-topbar-height));
+    transform: translateX(0);
+    box-shadow: var(--sage-shadow-lg);
+  }
+
+  .sage-sidebar.collapsed {
+    transform: translateX(-100%);
+    width: var(--sage-sidebar-width); /* Keep full width when hidden on mobile */
+  }
+
+  .sage-main {
+    width: 100%;
+  }
+}
+
 .sage-main {
   flex: 1;
   overflow-y: auto;
   overflow-x: hidden;
   padding: 24px;
   background-color: var(--sage-bg-primary);
+  min-width: 0; /* Prevent flex item from overflowing */
+  transition: margin-left 0.3s ease;
+}
+
+/* Responsive padding for mobile */
+@media (max-width: 768px) {
+  .sage-main {
+    padding: 16px;
+  }
+}
+
+@media (max-width: 480px) {
+  .sage-main {
+    padding: 12px;
+  }
 }
 
 /* ===== Stat Cards ===== */
@@ -719,18 +757,43 @@ body {
   color: var(--sage-text-secondary);
 }
 
-/* ===== Responsive ===== */
+/* ===== Responsive - Topbar ===== */
 @media (max-width: 768px) {
-  .sage-sidebar {
-    position: fixed;
-    left: 0;
-    top: var(--sage-topbar-height);
-    bottom: 0;
-    z-index: 200;
-    transform: translateX(-100%);
-    transition: transform 0.25s ease;
+  .sage-topbar {
+    padding: 0 8px;
+    gap: 6px;
   }
-  .sage-sidebar.mobile-open {
-    transform: translateX(0);
+  .sage-brand-title {
+    font-size: 16px;
+  }
+}
+
+@media (max-width: 480px) {
+  .sage-brand-title {
+    display: none;
+  }
+}
+
+/* ===== Responsive - Stat Cards ===== */
+@media (max-width: 768px) {
+  .stat-card {
+    padding: 14px;
+  }
+  .stat-card .stat-value {
+    font-size: 22px;
+  }
+  .stat-card .stat-label {
+    font-size: 12px;
+  }
+  .stat-card .stat-icon {
+    width: 32px;
+    height: 32px;
+    margin-bottom: 8px;
+  }
+  .quick-link {
+    padding: 14px;
+  }
+  .section-title {
+    font-size: 16px;
   }
 }
diff --git a/wwwroot/shell_theme.js b/wwwroot/shell_theme.js
index 2b86ddb..89f8de3 100644
--- a/wwwroot/shell_theme.js
+++ b/wwwroot/shell_theme.js
@@ -42,12 +42,61 @@
   function initSidebar() {
     var collapsed = false;
     try { collapsed = localStorage.getItem(SIDEBAR_KEY) === 'true'; } catch(e) {}
+    
+    // Auto-collapse on mobile
+    if (isMobile()) {
+      collapsed = true;
+    }
+    
     var sidebar = document.getElementById('sage_sidebar');
     if (sidebar && collapsed) {
       sidebar.classList.add('collapsed');
     }
   }
 
+  // Handle window resize - auto-collapse on mobile
+  function handleResize() {
+    var sidebar = document.getElementById('sage_sidebar');
+    if (!sidebar) return;
+    
+    if (isMobile() && !sidebar.classList.contains('collapsed')) {
+      sidebar.classList.add('collapsed');
+      try { localStorage.setItem(SIDEBAR_KEY, 'true'); } catch(e) {}
+      updateSidebarIcon(true);
+    }
+  }
+
+  // Check if we're on mobile viewport
+  function isMobile() {
+    return window.innerWidth <= 768;
+  }
+
+  // Close sidebar when clicking outside on mobile
+  function setupMobileOverlay() {
+    document.addEventListener('click', function(e) {
+      if (!isMobile()) return;
+      var sidebar = document.getElementById('sage_sidebar');
+      var toggleBtn = document.getElementById('sidebar_toggle_btn');
+      if (!sidebar || sidebar.classList.contains('collapsed')) return;
+      // If click is outside sidebar and toggle button, close sidebar
+      if (!sidebar.contains(e.target) && (!toggleBtn || !toggleBtn.contains(e.target))) {
+        sidebar.classList.add('collapsed');
+        try { localStorage.setItem(SIDEBAR_KEY, 'true'); } catch(ex) {}
+        updateSidebarIcon(true);
+      }
+    });
+  }
+
+  function updateSidebarIcon(isCollapsed) {
+    var btn = document.getElementById('sidebar_toggle_btn');
+    if (!btn) return;
+    if (isCollapsed) {
+      btn.innerHTML = '<svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="13 17 18 12 13 7"/><polyline points="6 17 11 12 6 7"/></svg>';
+    } else {
+      btn.innerHTML = '<svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="11 17 6 12 11 7"/><polyline points="18 17 13 12 18 7"/></svg>';
+    }
+  }
+
   // Toggle sidebar collapse
   function toggleSidebar() {
     var sidebar = document.getElementById('sage_sidebar');
@@ -55,16 +104,7 @@
     sidebar.classList.toggle('collapsed');
     var isCollapsed = sidebar.classList.contains('collapsed');
     try { localStorage.setItem(SIDEBAR_KEY, isCollapsed); } catch(e) {}
-
-    // Update toggle icon
-    var btn = document.getElementById('sidebar_toggle_btn');
-    if (btn) {
-      if (isCollapsed) {
-        btn.innerHTML = '<svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="13 17 18 12 13 7"/><polyline points="6 17 11 12 6 7"/></svg>';
-      } else {
-        btn.innerHTML = '<svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="11 17 6 12 11 7"/><polyline points="18 17 13 12 18 7"/></svg>';
-      }
-    }
+    updateSidebarIcon(isCollapsed);
   }
 
   // Initialize SPA Router
@@ -115,11 +155,15 @@
       initTheme();
       initSidebar();
       initRouter();
+      setupMobileOverlay();
+      window.addEventListener('resize', handleResize);
     });
   } else {
     initTheme();
     initSidebar();
     initRouter();
+    setupMobileOverlay();
+    window.addEventListener('resize', handleResize);
   }
 
   // Bricks widgets render asynchronously after DOMContentLoaded.
@@ -134,6 +178,18 @@
     }
   })();
 
+  // Retry sidebar icon init until the button element exists
+  (function retrySidebarIcon() {
+    var sidebar = document.getElementById('sage_sidebar');
+    var btn = document.getElementById('sidebar_toggle_btn');
+    if (btn && sidebar) {
+      var isCollapsed = sidebar.classList.contains('collapsed');
+      updateSidebarIcon(isCollapsed);
+    } else {
+      setTimeout(retrySidebarIcon, 200);
+    }
+  })();
+
   // Expose global functions for bricks bind access
   window.sageToggleTheme = toggleTheme;
   window.sageToggleSidebar = toggleSidebar;