svtrackpune/invoice-automation-saas ? reverse-engineered prompt

Build me a clean invoice automation SaaS website in Next.js that feels ready to ship.

I want a simple landing page and then an app area where a user can sign in, create invoices, track what is sent, paid, or overdue, and see a basic dashboard with totals and recent activity. Make it easy to add client details, invoice line items, due dates, and notes, then generate a nice looking invoice view that can be shared or downloaded.

Use the existing project structure and keep the design modern, responsive, and easy to understand. If it makes sense, connect it to the included backend setup so the data actually saves and loads properly. Add sensible empty states, loading states, and a few reusable components so the app feels polished instead of bare bones.

If you need current docs for anything, look them up online first and then build it in a way that fits a real SaaS product.