#pinia

Build a modern shopping cart using Vue 3 Composition API. Features: 1. Reactive cart state with Pinia store. 2. Add/remove items with smooth transitions. 3. Quantity adjustments with debounced updates. 4. Price calculations including tax and shipping. 5. Persistent cart using localStorage. 6. Empty state with product recommendations. 7. Checkout button with loading state. Use Tailwind for styling and Vueuse for composable utilities. Implement optimistic UI updates for better UX.