feat: redesign sidebar with icons, collapse toggle, and improved theme

- Add lucide icons to all navigation items
- Collapsible sidebar with icon-only mode and tooltips
- Narrower sidebar (w-60 vs w-64), compact top bar (h-12 vs h-14)
- Better search bar UX in top bar with keyboard shortcut hint
- Refined dark theme with better contrast and separation
- Custom thin scrollbar styling
- Backdrop blur for sidebar and top bar

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

it0-web-admin/src/app/(admin)/layout.tsx

@@ -21,11 +21,11 @@ export default function AdminLayout({ children }: { children: React.ReactNode })
   if (!ready) return null;
 
   return (
-    <div className="flex h-screen">
+    <div className="flex h-screen bg-background">
       <Sidebar />
-      <div className="flex-1 flex flex-col overflow-hidden">
+      <div className="flex-1 flex flex-col overflow-hidden min-w-0">
         <TopBar />
-        <main className="flex-1 overflow-y-auto p-6">
+        <main className="flex-1 overflow-y-auto scrollbar-thin p-5">
           {children}
         </main>
       </div>

it0-web-admin/src/presentation/components/layout/sidebar.tsx

@@ -1,21 +1,58 @@
 'use client';
 
-import { useState } from 'react';
+import { useState, createContext, useContext } from 'react';
 import Link from 'next/link';
 import { usePathname } from 'next/navigation';
 import { cn } from '@/lib/utils';
+import {
+  LayoutDashboard,
+  Bot,
+  BookOpen,
+  ClipboardList,
+  Server,
+  Activity,
+  Terminal,
+  Shield,
+  FileSearch,
+  MessageSquare,
+  Building2,
+  Settings,
+  ChevronRight,
+  PanelLeftClose,
+  PanelLeft,
+} from 'lucide-react';
+
+/* ---------- Sidebar context for collapse state ---------- */
+
+interface SidebarContextValue {
+  collapsed: boolean;
+  setCollapsed: (v: boolean) => void;
+}
+
+const SidebarContext = createContext<SidebarContextValue>({
+  collapsed: false,
+  setCollapsed: () => {},
+});
+
+export const useSidebar = () => useContext(SidebarContext);
+
+/* ---------- Nav config ---------- */
 
 interface NavItem {
   label: string;
   href: string;
+  icon: React.ReactNode;
   children?: { label: string; href: string }[];
 }
 
+const iconClass = 'h-4 w-4 shrink-0';
+
 const navItems: NavItem[] = [
-  { label: 'Dashboard', href: '/dashboard' },
+  { label: 'Dashboard', href: '/dashboard', icon: <LayoutDashboard className={iconClass} /> },
   {
     label: 'Agent Config',
     href: '/agent-config',
+    icon: <Bot className={iconClass} />,
     children: [
       { label: 'Engine & Prompt', href: '/agent-config' },
       { label: 'SDK Config', href: '/agent-config/sdk' },
@@ -23,11 +60,12 @@ const navItems: NavItem[] = [
       { label: 'Hooks', href: '/agent-config/hooks' },
     ],
   },
-  { label: 'Runbooks', href: '/runbooks' },
-  { label: 'Standing Orders', href: '/standing-orders' },
+  { label: 'Runbooks', href: '/runbooks', icon: <BookOpen className={iconClass} /> },
+  { label: 'Standing Orders', href: '/standing-orders', icon: <ClipboardList className={iconClass} /> },
   {
     label: 'Servers',
     href: '/servers',
+    icon: <Server className={iconClass} />,
     children: [
       { label: 'All Servers', href: '/servers' },
       { label: 'Clusters', href: '/servers/clusters' },
@@ -36,15 +74,17 @@ const navItems: NavItem[] = [
   {
     label: 'Monitoring',
     href: '/monitoring/alert-rules',
+    icon: <Activity className={iconClass} />,
     children: [
       { label: 'Alert Rules', href: '/monitoring/alert-rules' },
       { label: 'Health Checks', href: '/monitoring/health-checks' },
     ],
   },
-  { label: 'Terminal', href: '/terminal' },
+  { label: 'Terminal', href: '/terminal', icon: <Terminal className={iconClass} /> },
   {
     label: 'Security',
     href: '/security/risk-rules',
+    icon: <Shield className={iconClass} />,
     children: [
       { label: 'Risk Rules', href: '/security/risk-rules' },
       { label: 'Credentials', href: '/security/credentials' },
@@ -53,16 +93,19 @@ const navItems: NavItem[] = [
   {
     label: 'Audit',
     href: '/audit/logs',
+    icon: <FileSearch className={iconClass} />,
     children: [
       { label: 'Logs', href: '/audit/logs' },
       { label: 'Session Replay', href: '/audit/replay' },
     ],
   },
-  { label: 'Communication', href: '/communication' },
-  { label: 'Tenants', href: '/tenants' },
-  { label: 'Settings', href: '/settings' },
+  { label: 'Communication', href: '/communication', icon: <MessageSquare className={iconClass} /> },
+  { label: 'Tenants', href: '/tenants', icon: <Building2 className={iconClass} /> },
+  { label: 'Settings', href: '/settings', icon: <Settings className={iconClass} /> },
 ];
 
+/* ---------- Helpers ---------- */
+
 function isActive(pathname: string, href: string) {
   return pathname === href || pathname.startsWith(href + '/');
 }
@@ -72,81 +115,140 @@ function isGroupActive(pathname: string, item: NavItem) {
   return item.children?.some((c) => isActive(pathname, c.href)) ?? false;
 }
 
+/* ---------- Tooltip for collapsed mode ---------- */
+
+function Tooltip({ children, label }: { children: React.ReactNode; label: string }) {
+  return (
+    <div className="relative group/tip">
+      {children}
+      <div
+        className="absolute left-full top-1/2 -translate-y-1/2 ml-2 px-2.5 py-1 rounded-md
+                    bg-popover text-popover-foreground text-xs font-medium whitespace-nowrap
+                    shadow-md border opacity-0 pointer-events-none
+                    group-hover/tip:opacity-100 transition-opacity duration-150 z-50"
+      >
+        {label}
+      </div>
+    </div>
+  );
+}
+
+/* ---------- Main component ---------- */
+
 export function Sidebar() {
   const pathname = usePathname();
   const [expanded, setExpanded] = useState<Record<string, boolean>>({});
+  const [collapsed, setCollapsed] = useState(false);
 
   const toggle = (label: string) =>
     setExpanded((prev) => ({ ...prev, [label]: !prev[label] }));
 
   return (
-    <aside className="w-64 bg-card border-r flex flex-col">
-      <div className="p-4 border-b">
-        <h1 className="text-xl font-bold">IT0 Admin</h1>
-        <p className="text-xs text-muted-foreground">Operations Console</p>
+    <SidebarContext.Provider value={{ collapsed, setCollapsed }}>
+      <aside
+        className={cn(
+          'bg-card/50 backdrop-blur-sm border-r flex flex-col transition-all duration-200 ease-in-out',
+          collapsed ? 'w-16' : 'w-60',
+        )}
+      >
+        {/* Logo area */}
+        <div className={cn('border-b flex items-center', collapsed ? 'px-3 py-4 justify-center' : 'px-4 py-4')}>
+          <div className="flex items-center gap-2.5 min-w-0">
+            <div className="w-8 h-8 rounded-lg bg-primary/15 flex items-center justify-center shrink-0">
+              <span className="text-primary font-bold text-sm">IT</span>
             </div>
-      <nav className="flex-1 p-2 space-y-0.5 overflow-y-auto">
+            {!collapsed && (
+              <div className="min-w-0">
+                <h1 className="text-sm font-semibold tracking-tight truncate">IT0 Admin</h1>
+                <p className="text-[10px] text-muted-foreground leading-none mt-0.5">Operations Console</p>
+              </div>
+            )}
+          </div>
+        </div>
+
+        {/* Navigation */}
+        <nav className="flex-1 py-2 px-2 space-y-0.5 overflow-y-auto overflow-x-hidden">
           {navItems.map((item) => {
             const hasChildren = item.children && item.children.length > 0;
             const groupActive = isGroupActive(pathname, item);
             const isOpen = expanded[item.label] ?? groupActive;
 
+            /* ---- Collapsed: icon-only with tooltip ---- */
+            if (collapsed) {
+              const linkTarget = hasChildren
+                ? item.children![0].href
+                : item.href;
+              return (
+                <Tooltip key={item.label} label={item.label}>
+                  <Link
+                    href={linkTarget}
+                    className={cn(
+                      'flex items-center justify-center h-9 w-full rounded-md transition-colors',
+                      groupActive
+                        ? 'bg-primary/10 text-primary'
+                        : 'text-muted-foreground hover:bg-accent hover:text-foreground',
+                    )}
+                  >
+                    {item.icon}
+                  </Link>
+                </Tooltip>
+              );
+            }
+
+            /* ---- Expanded: no children ---- */
             if (!hasChildren) {
               return (
                 <Link
                   key={item.href}
                   href={item.href}
                   className={cn(
-                  'flex items-center gap-3 px-3 py-2 rounded-md text-sm transition-colors',
+                    'flex items-center gap-2.5 px-2.5 py-2 rounded-md text-[13px] transition-colors',
                     isActive(pathname, item.href)
-                    ? 'bg-primary/10 text-primary'
-                    : 'text-muted-foreground hover:bg-accent hover:text-accent-foreground',
+                      ? 'bg-primary/10 text-primary font-medium'
+                      : 'text-muted-foreground hover:bg-accent hover:text-foreground',
                   )}
                 >
-                <span>{item.label}</span>
+                  {item.icon}
+                  <span className="truncate">{item.label}</span>
                 </Link>
               );
             }
 
+            /* ---- Expanded: with children ---- */
             return (
               <div key={item.label}>
                 <button
                   onClick={() => toggle(item.label)}
                   className={cn(
-                  'flex items-center justify-between w-full px-3 py-2 rounded-md text-sm transition-colors',
+                    'flex items-center gap-2.5 w-full px-2.5 py-2 rounded-md text-[13px] transition-colors',
                     groupActive
                       ? 'text-primary'
-                    : 'text-muted-foreground hover:bg-accent hover:text-accent-foreground',
+                      : 'text-muted-foreground hover:bg-accent hover:text-foreground',
                   )}
                 >
-                <span>{item.label}</span>
-                <svg
+                  {item.icon}
+                  <span className="flex-1 text-left truncate">{item.label}</span>
+                  <ChevronRight
                     className={cn(
-                    'w-4 h-4 transition-transform',
+                      'h-3.5 w-3.5 shrink-0 transition-transform duration-200',
                       isOpen && 'rotate-90',
                     )}
-                  fill="none"
-                  viewBox="0 0 24 24"
-                  stroke="currentColor"
-                  strokeWidth={2}
-                >
-                  <path strokeLinecap="round" strokeLinejoin="round" d="M9 5l7 7-7 7" />
-                </svg>
+                  />
                 </button>
                 {isOpen && (
-                <div className="ml-4 mt-0.5 space-y-0.5">
+                  <div className="ml-[18px] mt-0.5 space-y-0.5 border-l border-border/50 pl-2.5">
                     {item.children!.map((child) => (
                       <Link
                         key={child.href}
                         href={child.href}
                         className={cn(
-                        'flex items-center gap-2 px-3 py-1.5 rounded-md text-xs transition-colors',
+                          'flex items-center px-2.5 py-1.5 rounded-md text-xs transition-colors',
                           isActive(pathname, child.href)
                             ? 'bg-primary/10 text-primary font-medium'
-                          : 'text-muted-foreground hover:bg-accent hover:text-accent-foreground',
+                            : 'text-muted-foreground hover:bg-accent hover:text-foreground',
                         )}
                       >
-                      <span>{child.label}</span>
+                        <span className="truncate">{child.label}</span>
                       </Link>
                     ))}
                   </div>
@@ -155,6 +257,28 @@ export function Sidebar() {
             );
           })}
         </nav>
+
+        {/* Collapse toggle at bottom */}
+        <div className="border-t p-2">
+          <button
+            onClick={() => setCollapsed(!collapsed)}
+            className={cn(
+              'flex items-center gap-2.5 w-full rounded-md text-xs text-muted-foreground',
+              'hover:bg-accent hover:text-foreground transition-colors',
+              collapsed ? 'justify-center h-9' : 'px-2.5 py-2',
+            )}
+          >
+            {collapsed ? (
+              <PanelLeft className="h-4 w-4 shrink-0" />
+            ) : (
+              <>
+                <PanelLeftClose className="h-4 w-4 shrink-0" />
+                <span>Collapse</span>
+              </>
+            )}
+          </button>
+        </div>
       </aside>
+    </SidebarContext.Provider>
   );
 }

it0-web-admin/src/presentation/components/layout/top-bar.tsx

@@ -1,26 +1,49 @@
 'use client';
 
 import { useTenantStore } from '@/stores/zustand/tenant-store';
+import { Search, Bell } from 'lucide-react';
 
 export function TopBar() {
   const { currentTenant } = useTenantStore();
 
   return (
-    <header className="h-14 border-b bg-card flex items-center justify-between px-6">
-      <div className="flex items-center gap-4">
-        <kbd className="px-2 py-1 text-xs bg-muted rounded border text-muted-foreground">
-          Cmd+K
+    <header className="h-12 border-b bg-card/50 backdrop-blur-sm flex items-center justify-between px-4 shrink-0">
+      {/* Left: search / command palette */}
+      <button
+        className="flex items-center gap-2 px-3 py-1.5 rounded-md border border-border/60
+                   text-muted-foreground hover:text-foreground hover:border-border
+                   transition-colors text-xs w-56"
+        onClick={() => {
+          /* TODO: open command palette */
+        }}
+      >
+        <Search className="h-3.5 w-3.5 shrink-0" />
+        <span className="flex-1 text-left">Search...</span>
+        <kbd className="text-[10px] bg-muted/60 px-1.5 py-0.5 rounded border border-border/40 font-mono">
+          ⌘K
         </kbd>
-        <span className="text-sm text-muted-foreground">Command Palette</span>
-      </div>
-      <div className="flex items-center gap-4">
-        <div className="text-sm">
+      </button>
+
+      {/* Right: tenant + user */}
+      <div className="flex items-center gap-3">
+        {/* Notification bell */}
+        <button className="relative p-1.5 rounded-md text-muted-foreground hover:text-foreground hover:bg-accent transition-colors">
+          <Bell className="h-4 w-4" />
+        </button>
+
+        {/* Divider */}
+        <div className="h-5 w-px bg-border" />
+
+        {/* Tenant indicator */}
+        <div className="text-xs">
           <span className="text-muted-foreground">Tenant: </span>
           <span className="font-medium">{currentTenant?.name || 'Not selected'}</span>
         </div>
-        <div className="w-8 h-8 rounded-full bg-primary/20 flex items-center justify-center text-sm font-medium">
+
+        {/* User avatar */}
+        <button className="w-7 h-7 rounded-full bg-primary/15 border border-primary/20 flex items-center justify-center text-xs font-semibold text-primary hover:bg-primary/25 transition-colors">
           A
-        </div>
+        </button>
       </div>
     </header>
   );

it0-web-admin/src/styles/globals.css

@@ -4,23 +4,25 @@
 
 @layer base {
   :root {
-    --background: 222.2 84% 4.9%;
-    --foreground: 210 40% 98%;
-    --card: 222.2 84% 4.9%;
-    --card-foreground: 210 40% 98%;
-    --primary: 217.2 91.2% 59.8%;
-    --primary-foreground: 222.2 47.4% 11.2%;
-    --secondary: 217.2 32.6% 17.5%;
-    --secondary-foreground: 210 40% 98%;
-    --muted: 217.2 32.6% 17.5%;
-    --muted-foreground: 215 20.2% 65.1%;
-    --accent: 217.2 32.6% 17.5%;
+    --background: 224 71% 4%;
+    --foreground: 213 31% 91%;
+    --card: 224 71% 4%;
+    --card-foreground: 213 31% 91%;
+    --popover: 224 71% 4%;
+    --popover-foreground: 213 31% 91%;
+    --primary: 210 100% 52%;
+    --primary-foreground: 0 0% 100%;
+    --secondary: 222 47% 11%;
+    --secondary-foreground: 213 31% 91%;
+    --muted: 223 47% 11%;
+    --muted-foreground: 215.4 16.3% 56.9%;
+    --accent: 216 34% 17%;
     --accent-foreground: 210 40% 98%;
-    --destructive: 0 62.8% 30.6%;
+    --destructive: 0 63% 31%;
     --destructive-foreground: 210 40% 98%;
-    --border: 217.2 32.6% 17.5%;
-    --input: 217.2 32.6% 17.5%;
-    --ring: 224.3 76.3% 48%;
+    --border: 216 34% 17%;
+    --input: 216 34% 17%;
+    --ring: 210 100% 52%;
     --radius: 0.5rem;
   }
 }
@@ -30,6 +32,27 @@
     @apply border-border;
   }
   body {
-    @apply bg-background text-foreground;
+    @apply bg-background text-foreground antialiased;
+  }
+}
+
+/* Custom scrollbar */
+@layer utilities {
+  .scrollbar-thin {
+    scrollbar-width: thin;
+    scrollbar-color: hsl(var(--border)) transparent;
+  }
+  .scrollbar-thin::-webkit-scrollbar {
+    width: 6px;
+  }
+  .scrollbar-thin::-webkit-scrollbar-track {
+    background: transparent;
+  }
+  .scrollbar-thin::-webkit-scrollbar-thumb {
+    background-color: hsl(var(--border));
+    border-radius: 3px;
+  }
+  .scrollbar-thin::-webkit-scrollbar-thumb:hover {
+    background-color: hsl(var(--muted-foreground) / 0.5);
   }
 }

it0-web-admin/tailwind.config.ts

@@ -34,6 +34,10 @@ const config: Config = {
           DEFAULT: 'hsl(var(--card))',
           foreground: 'hsl(var(--card-foreground))',
         },
+        popover: {
+          DEFAULT: 'hsl(var(--popover))',
+          foreground: 'hsl(var(--popover-foreground))',
+        },
         border: 'hsl(var(--border))',
         input: 'hsl(var(--input))',
         ring: 'hsl(var(--ring))',