<div class="h-[600px] w-full border border-border rounded-lg overflow-hidden flex bg-background">
  <aside class="w-64 border-r border-border bg-muted/30 flex flex-col hidden md:flex">
    <div class="h-14 border-b border-border flex items-center px-4 font-semibold">Dashboard</div>
    <div class="flex-1 p-4 space-y-2 text-sm">
      <div class="bg-accent px-3 py-2 rounded-md font-medium">Overview</div>
      <div class="px-3 py-2 text-muted-foreground hover:bg-accent/50 rounded-md cursor-pointer">Customers</div>
      <div class="px-3 py-2 text-muted-foreground hover:bg-accent/50 rounded-md cursor-pointer">Products</div>
      <div class="px-3 py-2 text-muted-foreground hover:bg-accent/50 rounded-md cursor-pointer">Settings</div>
    </div>
  </aside>
  <div class="flex-1 flex flex-col">
    <header class="h-14 border-b border-border flex items-center justify-between px-6 bg-background">
      <div class="md:hidden font-semibold">Dashboard</div>
      <input type="text" placeholder="Search..." class="hidden md:block h-9 w-64 rounded-md border border-input bg-background px-3 text-sm"/>
      <div class="h-8 w-8 rounded-full bg-primary text-primary-foreground flex items-center justify-center text-xs font-bold">U</div>
    </header>
    <main class="flex-1 p-6 overflow-auto bg-muted/10">
      <h2 class="text-2xl font-bold tracking-tight mb-4">Overview</h2>
      <div class="grid gap-4 md:grid-cols-2 lg:grid-cols-3 mb-4">
        <div class="rounded-xl border border-border bg-card p-6 shadow-sm"><div class="text-sm font-medium text-muted-foreground mb-1">Total Revenue</div><div class="text-2xl font-bold">$45,231.89</div></div>
        <div class="rounded-xl border border-border bg-card p-6 shadow-sm"><div class="text-sm font-medium text-muted-foreground mb-1">Subscriptions</div><div class="text-2xl font-bold">+2350</div></div>
        <div class="rounded-xl border border-border bg-card p-6 shadow-sm"><div class="text-sm font-medium text-muted-foreground mb-1">Active Now</div><div class="text-2xl font-bold">+12,234</div></div>
      </div>
      <div class="h-64 rounded-xl border border-border bg-card flex items-center justify-center text-muted-foreground text-sm shadow-sm">Main Content Area</div>
    </main>
  </div>
</div>