diff --git a/src/web/src/components/layout/AppHeader.tsx b/src/web/src/components/layout/AppHeader.tsx
index 77b27d3..895b285 100644
--- a/src/web/src/components/layout/AppHeader.tsx
+++ b/src/web/src/components/layout/AppHeader.tsx
@@ -57,7 +57,7 @@ export function AppHeader() {
           <SheetHeader className="sr-only">
             <SheetTitle>Navegación</SheetTitle>
           </SheetHeader>
-          <SidebarNav />
+          <SidebarNav forceExpanded />
         </SheetContent>
       </Sheet>
 
diff --git a/src/web/src/components/layout/AppSidebar.tsx b/src/web/src/components/layout/AppSidebar.tsx
index a46ac66..a92e9d3 100644
--- a/src/web/src/components/layout/AppSidebar.tsx
+++ b/src/web/src/components/layout/AppSidebar.tsx
@@ -9,10 +9,14 @@ import {
   Users,
   ShieldCheck,
   KeyRound,
+  PanelLeftClose,
+  PanelLeftOpen,
+  Newspaper,
 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { Badge } from '@/components/ui/badge'
 import { useAuthStore } from '@/stores/authStore'
+import { useSidebar } from '@/hooks/useSidebar'
 
 interface NavItem {
   label: string
@@ -25,127 +29,216 @@ const navItems: NavItem[] = [
   { label: 'Dashboard', href: '/', icon: LayoutDashboard },
   { label: 'Ventas', href: '/ventas', icon: ShoppingCart, disabled: true },
   { label: 'Tasación', href: '/tasacion', icon: Calculator, disabled: true },
-  {
-    label: 'Integraciones',
-    href: '/integraciones',
-    icon: Zap,
-    disabled: true,
-  },
-  {
-    label: 'Administración',
-    href: '/administracion',
-    icon: Settings,
-    disabled: true,
-  },
+  { label: 'Integraciones', href: '/integraciones', icon: Zap, disabled: true },
+  { label: 'Administración', href: '/administracion', icon: Settings, disabled: true },
 ]
 
-export function SidebarNav() {
+const adminItems: NavItem[] = [
+  { label: 'Usuarios', href: '/usuarios', icon: Users },
+  { label: 'Crear Usuario', href: '/usuarios/nuevo', icon: UserPlus },
+  { label: 'Roles', href: '/admin/roles', icon: ShieldCheck },
+  { label: 'Permisos', href: '/admin/permisos', icon: KeyRound },
+]
+
+interface SidebarNavProps {
+  /** When true forces expanded layout regardless of persisted state — used by mobile Sheet. */
+  forceExpanded?: boolean
+}
+
+export function SidebarNav({ forceExpanded = false }: SidebarNavProps) {
   const { pathname } = useLocation()
   const user = useAuthStore((s) => s.user)
   const isAdmin = user?.rol === 'admin'
+  const { collapsed: persisted, toggle } = useSidebar()
+  const collapsed = forceExpanded ? false : persisted
+
+  function isItemActive(item: NavItem): boolean {
+    if (item.disabled) return false
+    if (item.href === '/') return pathname === '/'
+    if (item.href === '/usuarios') {
+      return pathname.startsWith('/usuarios') && pathname !== '/usuarios/nuevo'
+    }
+    if (item.href === '/usuarios/nuevo') return pathname === '/usuarios/nuevo'
+    return pathname.startsWith(item.href)
+  }
 
   return (
-    <aside className="flex h-full flex-col bg-background border-r border-border">
+    <aside
+      className={cn(
+        'flex h-full flex-col bg-card text-card-foreground overflow-hidden transition-[width] duration-200 ease-out',
+        collapsed ? 'w-[68px]' : 'w-60',
+      )}
+      data-collapsed={collapsed}
+    >
       {/* Brand */}
-      <div className="flex h-14 items-center px-4 border-b border-border">
-        <span className="text-base font-semibold tracking-tight text-foreground">
-          SIG-CM 2.0
-        </span>
+      <div className="flex h-14 items-center border-b border-border px-3 shrink-0">
+        <div className="flex h-9 w-9 items-center justify-center rounded-lg bg-gradient-to-br from-brand-500 to-violet-500 shadow-md shadow-brand-500/20 shrink-0">
+          <Newspaper className="h-4 w-4 text-white" strokeWidth={2.25} />
+        </div>
+        {!collapsed && (
+          <span className="ml-3 text-sm font-semibold tracking-tight text-foreground truncate">
+            SIG-CM 2.0
+          </span>
+        )}
       </div>
 
       {/* Nav */}
-      <nav className="flex-1 overflow-y-auto py-4 px-2 space-y-1">
-        {navItems.map((item) => {
-          const Icon = item.icon
-          const isActive = pathname === item.href && !item.disabled
+      <nav className="flex-1 overflow-y-auto overflow-x-hidden py-3 px-2 space-y-1">
+        {navItems.map((item) => (
+          <NavRow
+            key={item.href}
+            item={item}
+            collapsed={collapsed}
+            active={isItemActive(item)}
+          />
+        ))}
 
-          return item.disabled ? (
-            <div
-              key={item.href}
-              className="flex items-center gap-3 rounded-md px-3 py-2 text-sm text-muted-foreground cursor-not-allowed opacity-60"
-            >
-              <Icon className="h-4 w-4 shrink-0" />
-              <span className="flex-1">{item.label}</span>
-              <Badge variant="secondary" className="text-xs">
-                Próximamente
-              </Badge>
-            </div>
-          ) : (
-            <Link
-              key={item.href}
-              to={item.href}
-              className={cn(
-                'flex items-center gap-3 rounded-md px-3 py-2 text-sm transition-colors hover:bg-accent hover:text-accent-foreground',
-                isActive
-                  ? 'bg-accent text-accent-foreground font-medium'
-                  : 'text-muted-foreground',
-              )}
-            >
-              <Icon className="h-4 w-4 shrink-0" />
-              <span>{item.label}</span>
-            </Link>
-          )
-        })}
-
-        {/* Admin-only section */}
         {isAdmin && (
           <>
-            <div className="pt-2 pb-1 px-3">
-              <span className="text-xs font-semibold uppercase tracking-wider text-muted-foreground/60">
-                Administración
-              </span>
-            </div>
-            <Link
-              to="/usuarios"
-              className={cn(
-                'flex items-center gap-3 rounded-md px-3 py-2 text-sm transition-colors hover:bg-accent hover:text-accent-foreground',
-                pathname.startsWith('/usuarios') && pathname !== '/usuarios/nuevo'
-                  ? 'bg-accent text-accent-foreground font-medium'
-                  : 'text-muted-foreground',
-              )}
-            >
-              <Users className="h-4 w-4 shrink-0" />
-              <span>Usuarios</span>
-            </Link>
-            <Link
-              to="/usuarios/nuevo"
-              className={cn(
-                'flex items-center gap-3 rounded-md px-3 py-2 text-sm transition-colors hover:bg-accent hover:text-accent-foreground',
-                pathname === '/usuarios/nuevo'
-                  ? 'bg-accent text-accent-foreground font-medium'
-                  : 'text-muted-foreground',
-              )}
-            >
-              <UserPlus className="h-4 w-4 shrink-0" />
-              <span>Crear Usuario</span>
-            </Link>
-            <Link
-              to="/admin/roles"
-              className={cn(
-                'flex items-center gap-3 rounded-md px-3 py-2 text-sm transition-colors hover:bg-accent hover:text-accent-foreground',
-                pathname.startsWith('/admin/roles')
-                  ? 'bg-accent text-accent-foreground font-medium'
-                  : 'text-muted-foreground',
-              )}
-            >
-              <ShieldCheck className="h-4 w-4 shrink-0" />
-              <span>Roles</span>
-            </Link>
-            <Link
-              to="/admin/permisos"
-              className={cn(
-                'flex items-center gap-3 rounded-md px-3 py-2 text-sm transition-colors hover:bg-accent hover:text-accent-foreground',
-                pathname.startsWith('/admin/permisos')
-                  ? 'bg-accent text-accent-foreground font-medium'
-                  : 'text-muted-foreground',
-              )}
-            >
-              <KeyRound className="h-4 w-4 shrink-0" />
-              <span>Permisos</span>
-            </Link>
+            <SectionLabel collapsed={collapsed}>Administración</SectionLabel>
+            {adminItems.map((item) => (
+              <NavRow
+                key={item.href}
+                item={item}
+                collapsed={collapsed}
+                active={isItemActive(item)}
+              />
+            ))}
           </>
         )}
       </nav>
+
+      {/* Collapse toggle — visible only on desktop (no en Sheet) */}
+      {!forceExpanded && (
+        <div className="border-t border-border p-2 shrink-0">
+          <button
+            type="button"
+            onClick={toggle}
+            aria-label={collapsed ? 'Expandir sidebar' : 'Colapsar sidebar'}
+            className={cn(
+              'group/toggle relative w-full flex items-center gap-3 rounded-md px-3 py-2 text-sm transition-colors',
+              'text-muted-foreground hover:bg-accent hover:text-accent-foreground',
+              collapsed && 'justify-center',
+            )}
+          >
+            {collapsed ? (
+              <PanelLeftOpen className="h-4 w-4 shrink-0" />
+            ) : (
+              <PanelLeftClose className="h-4 w-4 shrink-0" />
+            )}
+            {!collapsed && <span>Colapsar</span>}
+            {collapsed && (
+              <SidebarTooltip>Expandir</SidebarTooltip>
+            )}
+          </button>
+        </div>
+      )}
     </aside>
   )
 }
+
+/* ────────────────────────────────────────────────────────────────
+   Sub-componentes
+   ──────────────────────────────────────────────────────────────── */
+
+interface NavRowProps {
+  item: NavItem
+  collapsed: boolean
+  active: boolean
+}
+
+function NavRow({ item, collapsed, active }: NavRowProps) {
+  const Icon = item.icon
+
+  const baseClasses = cn(
+    'group/item relative flex items-center rounded-md text-sm transition-colors',
+    collapsed ? 'justify-center h-10 px-0' : 'gap-3 px-3 py-2',
+  )
+
+  if (item.disabled) {
+    return (
+      <div
+        className={cn(
+          baseClasses,
+          'text-muted-foreground/70 cursor-not-allowed opacity-60',
+        )}
+        aria-disabled="true"
+      >
+        <Icon className="h-4 w-4 shrink-0" />
+        {!collapsed && (
+          <>
+            <span className="flex-1 truncate">{item.label}</span>
+            <Badge variant="secondary" className="text-[10px] px-1.5 py-0 shrink-0">
+              Próx.
+            </Badge>
+          </>
+        )}
+        {collapsed && <SidebarTooltip>{item.label} · Próximamente</SidebarTooltip>}
+      </div>
+    )
+  }
+
+  return (
+    <Link
+      to={item.href}
+      className={cn(
+        baseClasses,
+        active
+          ? 'bg-accent text-accent-foreground font-medium'
+          : 'text-muted-foreground hover:bg-accent hover:text-accent-foreground',
+      )}
+      aria-current={active ? 'page' : undefined}
+    >
+      {/* Active indicator bar (left edge) — sutil cuando expanded, dot cuando collapsed */}
+      {active && !collapsed && (
+        <span className="absolute left-0 top-1/2 -translate-y-1/2 h-5 w-0.5 rounded-r-full bg-primary" />
+      )}
+      <Icon className="h-4 w-4 shrink-0" />
+      {!collapsed && <span className="truncate">{item.label}</span>}
+      {collapsed && <SidebarTooltip>{item.label}</SidebarTooltip>}
+    </Link>
+  )
+}
+
+function SectionLabel({
+  collapsed,
+  children,
+}: {
+  collapsed: boolean
+  children: React.ReactNode
+}) {
+  if (collapsed) {
+    return (
+      <div className="my-2 mx-2 border-t border-border" aria-hidden="true" />
+    )
+  }
+  return (
+    <div className="pt-3 pb-1 px-3">
+      <span className="text-[10px] font-semibold uppercase tracking-wider text-muted-foreground/60">
+        {children}
+      </span>
+    </div>
+  )
+}
+
+/**
+ * Custom tooltip que aparece a la derecha del item cuando el sidebar está collapsed.
+ * Sin radix dep — pure CSS hover + group selector. Se posiciona absolute fuera del sidebar.
+ */
+function SidebarTooltip({ children }: { children: React.ReactNode }) {
+  return (
+    <span
+      role="tooltip"
+      className={cn(
+        'pointer-events-none absolute left-full ml-3 top-1/2 -translate-y-1/2 z-50',
+        'whitespace-nowrap rounded-md border border-border bg-popover px-2.5 py-1.5',
+        'text-xs font-medium text-popover-foreground shadow-lg',
+        'opacity-0 -translate-x-1 transition-all duration-150',
+        'group-hover/item:opacity-100 group-hover/item:translate-x-0',
+        'group-hover/toggle:opacity-100 group-hover/toggle:translate-x-0',
+      )}
+    >
+      {children}
+    </span>
+  )
+}
diff --git a/src/web/src/hooks/useSidebar.ts b/src/web/src/hooks/useSidebar.ts
new file mode 100644
index 0000000..490539e
--- /dev/null
+++ b/src/web/src/hooks/useSidebar.ts
@@ -0,0 +1,24 @@
+import { useEffect, useState, useCallback } from 'react'
+
+const STORAGE_KEY = 'sidebar-collapsed'
+
+function readInitial(): boolean {
+  if (typeof window === 'undefined') return false
+  return window.localStorage.getItem(STORAGE_KEY) === '1'
+}
+
+/**
+ * Manages desktop sidebar collapsed state with localStorage persistence.
+ * Mobile sidebar (Sheet) is independent — this hook only affects desktop ≥ lg.
+ */
+export function useSidebar() {
+  const [collapsed, setCollapsed] = useState<boolean>(readInitial)
+
+  useEffect(() => {
+    window.localStorage.setItem(STORAGE_KEY, collapsed ? '1' : '0')
+  }, [collapsed])
+
+  const toggle = useCallback(() => setCollapsed((prev) => !prev), [])
+
+  return { collapsed, setCollapsed, toggle }
+}
diff --git a/src/web/src/layouts/ProtectedLayout.tsx b/src/web/src/layouts/ProtectedLayout.tsx
index a5a5870..3c7c9e2 100644
--- a/src/web/src/layouts/ProtectedLayout.tsx
+++ b/src/web/src/layouts/ProtectedLayout.tsx
@@ -16,8 +16,8 @@ export function ProtectedLayout({ children }: ProtectedLayoutProps) {
       <div className="absolute top-[-15%] right-[-8%] w-[500px] h-[500px] rounded-full bg-brand-500/10 dark:bg-brand-500/12 blur-[140px] pointer-events-none" />
       <div className="absolute bottom-[-15%] left-[20%] w-[500px] h-[500px] rounded-full bg-violet-500/8 dark:bg-violet-500/10 blur-[140px] pointer-events-none" />
 
-      {/* Desktop sidebar */}
-      <div className="relative z-10 hidden lg:flex lg:w-60 lg:flex-col lg:shrink-0 border-r border-border">
+      {/* Desktop sidebar — width controlled by SidebarNav itself (collapsed/expanded) */}
+      <div className="relative z-10 hidden lg:flex lg:flex-col lg:shrink-0 border-r border-border">
         <SidebarNav />
       </div>