diff --git a/docs/project-roadmap.md b/docs/project-roadmap.md
index 483509e4..7625d7ca 100644
--- a/docs/project-roadmap.md
+++ b/docs/project-roadmap.md
@@ -437,6 +437,16 @@ src/types/
    - Deployment pipelines with type checks
    - Infrastructure as Code with TypeScript
 
+#### Phase 4: UI Enhancements - Sidebar Redesign (v4.7.0)
+**Timeline**: 1-2 months (TBD)
+
+**Priorities**:
+1. **Sidebar Redesign Implementation**
+   - Implement new sidebar component with modern UI/UX principles.
+   - Ensure responsiveness across different screen sizes.
+   - Integrate with existing routing and navigation logic.
+   - Improve accessibility features for the sidebar.
+
 ### Technical Debt Resolution
 
 #### Immediate Priorities (v4.4.1)
diff --git a/ui/bun.lock b/ui/bun.lock
index 481fbc61..4d5fd5d2 100644
--- a/ui/bun.lock
+++ b/ui/bun.lock
@@ -6,6 +6,7 @@
       "dependencies": {
         "@hookform/resolvers": "^5.2.2",
         "@radix-ui/react-alert-dialog": "^1.1.15",
+        "@radix-ui/react-collapsible": "^1.1.12",
         "@radix-ui/react-dialog": "^1.1.15",
         "@radix-ui/react-dropdown-menu": "^2.1.16",
         "@radix-ui/react-label": "^2.1.8",
@@ -189,6 +190,8 @@
 
     "@radix-ui/react-arrow": ["@radix-ui/react-arrow@1.1.7", "", { "dependencies": { "@radix-ui/react-primitive": "2.1.3" }, "peerDependencies": { "@types/react": "*", "@types/react-dom": "*", "react": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc", "react-dom": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc" }, "optionalPeers": ["@types/react", "@types/react-dom"] }, "sha512-F+M1tLhO+mlQaOWspE8Wstg+z6PwxwRd8oQ8IXceWz92kfAmalTRf0EjrouQeo7QssEPfCn05B4Ihs1K9WQ/7w=="],
 
+    "@radix-ui/react-collapsible": ["@radix-ui/react-collapsible@1.1.12", "", { "dependencies": { "@radix-ui/primitive": "1.1.3", "@radix-ui/react-compose-refs": "1.1.2", "@radix-ui/react-context": "1.1.2", "@radix-ui/react-id": "1.1.1", "@radix-ui/react-presence": "1.1.5", "@radix-ui/react-primitive": "2.1.3", "@radix-ui/react-use-controllable-state": "1.2.2", "@radix-ui/react-use-layout-effect": "1.1.1" }, "peerDependencies": { "@types/react": "*", "@types/react-dom": "*", "react": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc", "react-dom": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc" }, "optionalPeers": ["@types/react", "@types/react-dom"] }, "sha512-Uu+mSh4agx2ib1uIGPP4/CKNULyajb3p92LsVXmH2EHVMTfZWpll88XJ0j4W0z3f8NK1eYl1+Mf/szHPmcHzyA=="],
+
     "@radix-ui/react-collection": ["@radix-ui/react-collection@1.1.7", "", { "dependencies": { "@radix-ui/react-compose-refs": "1.1.2", "@radix-ui/react-context": "1.1.2", "@radix-ui/react-primitive": "2.1.3", "@radix-ui/react-slot": "1.2.3" }, "peerDependencies": { "@types/react": "*", "@types/react-dom": "*", "react": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc", "react-dom": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc" }, "optionalPeers": ["@types/react", "@types/react-dom"] }, "sha512-Fh9rGN0MoI4ZFUNyfFVNU4y9LUz93u9/0K+yLgA2bwRojxM8JU1DyvvMBabnZPBgMWREAJvU2jjVzq+LrFUglw=="],
 
     "@radix-ui/react-compose-refs": ["@radix-ui/react-compose-refs@1.1.2", "", { "peerDependencies": { "@types/react": "*", "react": "^16.8 || ^17.0 || ^18.0 || ^19.0 || ^19.0.0-rc" }, "optionalPeers": ["@types/react"] }, "sha512-z4eqJvfiNnFMHIIvXP3CY57y2WJs5g2v3X0zm9mEJkrkNv4rDxu+sg9Jh8EkXyeqBkB7SOcboo9dMVqhyrACIg=="],
diff --git a/ui/package.json b/ui/package.json
index d4d847dc..fef4ae5e 100644
--- a/ui/package.json
+++ b/ui/package.json
@@ -17,6 +17,7 @@
   "dependencies": {
     "@hookform/resolvers": "^5.2.2",
     "@radix-ui/react-alert-dialog": "^1.1.15",
+    "@radix-ui/react-collapsible": "^1.1.12",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-dropdown-menu": "^2.1.16",
     "@radix-ui/react-label": "^2.1.8",
diff --git a/ui/src/App.tsx b/ui/src/App.tsx
index bf31d3d8..52f572ba 100644
--- a/ui/src/App.tsx
+++ b/ui/src/App.tsx
@@ -29,6 +29,7 @@ function Layout() {
           </div>
         </header>
         <Outlet />
+        <LocalhostDisclaimer />
       </main>
     </SidebarProvider>
   );
@@ -50,7 +51,6 @@ export default function App() {
           </Route>
         </Routes>
         <Toaster position="top-right" />
-        <LocalhostDisclaimer />
       </BrowserRouter>
     </QueryClientProvider>
   );
diff --git a/ui/src/components/app-sidebar.tsx b/ui/src/components/app-sidebar.tsx
index 4a1617bf..670570e6 100644
--- a/ui/src/components/app-sidebar.tsx
+++ b/ui/src/components/app-sidebar.tsx
@@ -1,51 +1,136 @@
 import { Link, useLocation } from 'react-router-dom';
-import { Home, Key, Zap, Users, Settings, Activity, FolderOpen } from 'lucide-react';
+import { Home, Key, Zap, Users, Settings, Activity, FolderOpen, ChevronRight } from 'lucide-react';
 import {
   Sidebar,
   SidebarContent,
   SidebarMenu,
   SidebarMenuItem,
   SidebarMenuButton,
+  SidebarMenuSub,
+  SidebarMenuSubItem,
+  SidebarMenuSubButton,
+  SidebarGroup,
+  SidebarGroupLabel,
   SidebarHeader,
   SidebarFooter,
   SidebarTrigger,
+  SidebarGroupContent,
 } from '@/components/ui/sidebar';
 import { CcsLogo } from '@/components/ccs-logo';
 import { useSidebar } from '@/hooks/use-sidebar';
+import { Collapsible, CollapsibleContent, CollapsibleTrigger } from '@/components/ui/collapsible';
 
-const navItems = [
-  { path: '/', icon: Home, label: 'Home' },
-  { path: '/api', icon: Key, label: 'API Profiles' },
-  { path: '/cliproxy', icon: Zap, label: 'CLIProxy' },
-  { path: '/accounts', icon: Users, label: 'Accounts' },
-  { path: '/settings', icon: Settings, label: 'Settings' },
-  { path: '/health', icon: Activity, label: 'Health' },
-  { path: '/shared', icon: FolderOpen, label: 'Shared Data' },
+// Define navigation groups
+const navGroups = [
+  {
+    title: 'General',
+    items: [{ path: '/', icon: Home, label: 'Home' }],
+  },
+  {
+    title: 'Identity & Access',
+    items: [
+      { path: '/api', icon: Key, label: 'API Profiles' },
+      { path: '/cliproxy', icon: Zap, label: 'CLIProxy' },
+      {
+        path: '/accounts',
+        icon: Users,
+        label: 'Accounts',
+        isCollapsible: true,
+        children: [
+          { path: '/accounts', label: 'All Accounts' },
+          { path: '/shared', icon: FolderOpen, label: 'Shared Data' },
+        ],
+      },
+    ],
+  },
+  {
+    title: 'System',
+    items: [
+      { path: '/health', icon: Activity, label: 'Health' },
+      { path: '/settings', icon: Settings, label: 'Settings' },
+    ],
+  },
 ];
 
 export function AppSidebar() {
   const location = useLocation();
   const { state } = useSidebar();
 
+  // Helper to check if a route is active (including sub-routes if needed)
+  const isRouteActive = (path: string) => location.pathname === path;
+
+  // Helper to check if a group/parent should be open based on active child
+  const isParentActive = (children: { path: string }[]) => {
+    return children.some((child) => isRouteActive(child.path));
+  };
+
   return (
     <Sidebar collapsible="icon">
       <SidebarHeader className="h-12 flex items-center justify-center">
         <CcsLogo size="sm" showText={state === 'expanded'} />
       </SidebarHeader>
+
       <SidebarContent>
-        <SidebarMenu>
-          {navItems.map((item) => (
-            <SidebarMenuItem key={item.path}>
-              <SidebarMenuButton asChild isActive={location.pathname === item.path}>
-                <Link to={item.path}>
-                  <item.icon className="w-4 h-4" />
-                  <span className="group-data-[collapsible=icon]:hidden">{item.label}</span>
-                </Link>
-              </SidebarMenuButton>
-            </SidebarMenuItem>
-          ))}
-        </SidebarMenu>
+        {navGroups.map((group, index) => (
+          <SidebarGroup key={group.title || index}>
+            {group.title && <SidebarGroupLabel>{group.title}</SidebarGroupLabel>}
+            <SidebarGroupContent>
+              <SidebarMenu>
+                {group.items.map((item) => (
+                  <SidebarMenuItem key={item.path}>
+                    {item.isCollapsible && item.children ? (
+                      <Collapsible
+                        defaultOpen={isParentActive(item.children) || isRouteActive(item.path)}
+                        className="group/collapsible"
+                      >
+                        <SidebarMenuItem>
+                          <CollapsibleTrigger asChild>
+                            <SidebarMenuButton tooltip={item.label}>
+                              {item.icon && <item.icon className="w-4 h-4" />}
+                              <span className="group-data-[collapsible=icon]:hidden">
+                                {item.label}
+                              </span>
+                              <ChevronRight className="ml-auto transition-transform duration-200 group-data-[state=open]/collapsible:rotate-90 group-data-[collapsible=icon]:hidden" />
+                            </SidebarMenuButton>
+                          </CollapsibleTrigger>
+                          <CollapsibleContent>
+                            <SidebarMenuSub>
+                              {item.children.map((child) => (
+                                <SidebarMenuSubItem key={child.path}>
+                                  <SidebarMenuSubButton
+                                    asChild
+                                    isActive={isRouteActive(child.path)}
+                                  >
+                                    <Link to={child.path}>
+                                      <span>{child.label}</span>
+                                    </Link>
+                                  </SidebarMenuSubButton>
+                                </SidebarMenuSubItem>
+                              ))}
+                            </SidebarMenuSub>
+                          </CollapsibleContent>
+                        </SidebarMenuItem>
+                      </Collapsible>
+                    ) : (
+                      <SidebarMenuButton
+                        asChild
+                        isActive={isRouteActive(item.path)}
+                        tooltip={item.label}
+                      >
+                        <Link to={item.path}>
+                          {item.icon && <item.icon className="w-4 h-4" />}
+                          <span className="group-data-[collapsible=icon]:hidden">{item.label}</span>
+                        </Link>
+                      </SidebarMenuButton>
+                    )}
+                  </SidebarMenuItem>
+                ))}
+              </SidebarMenu>
+            </SidebarGroupContent>
+          </SidebarGroup>
+        ))}
       </SidebarContent>
+
       <SidebarFooter className="p-4 border-t flex items-center justify-center">
         <SidebarTrigger />
       </SidebarFooter>
diff --git a/ui/src/components/localhost-disclaimer.tsx b/ui/src/components/localhost-disclaimer.tsx
index 8e83b90c..8368143b 100644
--- a/ui/src/components/localhost-disclaimer.tsx
+++ b/ui/src/components/localhost-disclaimer.tsx
@@ -1,24 +1,42 @@
 import { Shield, X } from 'lucide-react';
 import { useState } from 'react';
+import { useSidebar } from '@/hooks/use-sidebar';
 
 export function LocalhostDisclaimer() {
   const [dismissed, setDismissed] = useState(false);
+  const { state, isMobile } = useSidebar();
 
   if (dismissed) return null;
 
+  // Calculate the left margin based on sidebar state
+  // When expanded: sidebar width is 16rem
+  // When collapsed: sidebar width is 3rem
+  // On mobile: sidebar is overlay, no margin needed
+  const getLeftMargin = () => {
+    if (isMobile) return '0';
+    return state === 'expanded' ? '16rem' : '3rem';
+  };
+
   return (
-    <div className="fixed bottom-0 left-0 right-0 bg-yellow-50 dark:bg-yellow-900/20 border-t border-yellow-200 dark:border-yellow-800 px-4 py-2">
-      <div className="flex items-center justify-between max-w-7xl mx-auto">
+    <div
+      className="fixed bottom-0 bg-yellow-50 dark:bg-yellow-900/20 border-t border-yellow-200 dark:border-yellow-800 px-4 py-2 transition-all duration-200 ease-linear z-50"
+      style={{
+        left: getLeftMargin(),
+        right: '0',
+      }}
+    >
+      <div className="flex items-center justify-between max-w-7xl">
         <div className="flex items-center gap-2 text-sm text-yellow-800 dark:text-yellow-200">
-          <Shield className="w-4 h-4" />
-          <span>
-            This dashboard runs locally. All data stays on your machine. Never expose this server to
-            the internet.
+          <Shield className="w-4 h-4 flex-shrink-0" />
+          <span className="hidden sm:inline">
+            This dashboard runs locally. All data stays on your machine.
           </span>
+          <span className="sm:hidden">Local dashboard - data stays on your device.</span>
         </div>
         <button
           onClick={() => setDismissed(true)}
-          className="text-yellow-600 hover:text-yellow-800 dark:text-yellow-400"
+          className="text-yellow-600 hover:text-yellow-800 dark:text-yellow-400 flex-shrink-0 p-1 rounded hover:bg-yellow-100 dark:hover:bg-yellow-800/30 transition-colors"
+          aria-label="Dismiss disclaimer"
         >
           <X className="w-4 h-4" />
         </button>
diff --git a/ui/src/components/ui/collapsible.tsx b/ui/src/components/ui/collapsible.tsx
new file mode 100644
index 00000000..86ab87d8
--- /dev/null
+++ b/ui/src/components/ui/collapsible.tsx
@@ -0,0 +1,11 @@
+'use client';
+
+import * as CollapsiblePrimitive from '@radix-ui/react-collapsible';
+
+const Collapsible = CollapsiblePrimitive.Root;
+
+const CollapsibleTrigger = CollapsiblePrimitive.CollapsibleTrigger;
+
+const CollapsibleContent = CollapsiblePrimitive.CollapsibleContent;
+
+export { Collapsible, CollapsibleTrigger, CollapsibleContent };