priyadharshini-runku/hack ? reverse-engineered prompt

Build me a simple modern web app with a clean responsive front end and a small backend so it can actually save and fetch data.

I want the app to feel polished on desktop and mobile, with a nice landing page, a main working screen, and a few basic interactions like forms, buttons, loading states, and success or error messages. Use the existing project setup and make it easy to run locally. If you need to look up anything current, go ahead and check the latest docs online.

Keep the design simple but attractive, use a good color palette, and make sure the whole thing is wired up end to end so the UI talks to the server properly. If there are obvious places to improve the layout or user flow, go ahead and make those choices for me.