teja-sadha/Login_page_MERN ? reverse-engineered prompt

Build me a modern login and signup app with a clean, polished UI and a working backend so users can create an account, log in, and stay signed in with JWT.

I want the app to use MongoDB to store users, save passwords securely, and protect private pages so only authenticated users can access them. Please include a simple responsive frontend with form validation, error messages, loading states, and a nice dashboard or home screen after login. Add logout too, and make sure the whole flow feels smooth on desktop and mobile.

If anything is unclear, use current docs online and make sensible choices, but keep it simple and practical. I want the final result to be ready to run and easy to understand.