jeetjm/campusmart ? reverse-engineered prompt

Build me a simple campus marketplace web app where students can buy, sell, exchange, and rent items with each other.

I want it to feel clean and easy to use, with a homepage that shows listed items, a way to post new listings, search or filter by category, and a product detail page with photos, price, condition, and seller info. It should also support a basic message or contact flow so buyers can reach sellers, plus simple account pages for signing in and seeing your own listings. Make it work as a full app with a frontend and backend, and keep the experience focused on a student community. If you need to check current docs or best practices while building it, go ahead and look them up online.