Now let me check what UI components are available to build the sidebar:

There's already a sidebar component available. Let me read it to understand the patterns:

Now I have all the context I need. Let me create the dark theme sidebar with the modern SaaS styling. I'll update the globals.css with a dark theme and create the sidebar component.

Now let me create the app sidebar component:

Now let me create the main page that showcases the sidebar:

I've created a modern SaaS dashboard sidebar with a dark theme. The sidebar features:

• Workspace Switcher at the top with a dropdown to switch between multiple workspaces (Acme Inc, Personal, Startup Co)
• Search Input for quick navigation
• Main Navigation with collapsible menu items including Dashboard, Analytics, Projects, Team, and Documents
• Quick Access section with Starred and Recent items showing badge counts
• Upgrade Banner promoting Pro features with a gradient background
• Bottom Navigation with Notifications (with unread count), Settings, and Help
• User Profile Footer with avatar, name, email, and a dropdown menu for account options and logout

The design uses a pure dark color palette with subtle borders and hover states, closely inspired by the Vercel dashboard aesthetic with clean typography and a professional SaaS feel.