iamakhilvarun/Flask_web_application ? reverse-engineered prompt

Build me a simple Flask website from this repo that actually runs cleanly and looks polished.

I want a home page and a few basic pages that feel like a small real site, with a clean layout, navigation, and responsive design so it works on phone and desktop. If there are templates or static assets needed, organize them in a sensible way and wire everything up from the main app file. Make sure the app starts without errors, the routes are connected correctly, and the pages render properly.

If there is anything missing or unclear, set it up in the most practical way and use current docs online if you need to. Keep it simple, readable, and easy to extend later. Also make sure any app settings or instance data needed for Flask are handled properly so it behaves like a normal working project, not just a demo.