strudast/mern-crash-course ? reverse-engineered prompt

Build me a simple full stack MERN app from this repo, with a clean responsive frontend and a small backend API connected to MongoDB.

I want the app to feel polished on mobile and desktop, use Chakra UI for the interface, and include basic error handling so it does not break on bad requests or missing data. Make sure the frontend talks to the backend properly, and the backend can connect to a Mongo database using an env file for the connection string and port.

Please set it up so I can run the project locally, build it, and start it without extra manual steps. If you need current setup details or best practices for any of the libraries, look them up online and use the latest docs. Keep the code straightforward and easy to follow, since this is meant to be a crash course style project.