Establish the core application using Next.js and integrate TypeScript for robust type safety across all components and hooks.
Define the sidebar's open/closed state (`isExpanded`) using React's `useState`. Share this state globally via `Context` for access in the main layout.
Apply Tailwind CSS for responsive sizing and conditional width/translation classes. Use CSS transitions for a smooth expand and collapse animation.
Implement a toggle button using a professional Heroicon (e.g., Menu or Chevron) that calls the `toggleSidebar` function from the Context API.