parham7991/11 ? reverse-engineered prompt

Build me a clean Next.js app from this repo, something polished and ready to ship, not just a bare starter.

I want a simple modern site with a nice homepage, a couple of basic app pages, responsive styling, and a layout that looks good on mobile and desktop. Keep the code organized, make sure the app runs, builds, and tests without errors, and wire up whatever common setup is needed for a real project, like environment handling, middleware, and any basic lint or formatting config that fits. If there are missing details, make sensible choices and look up current docs online if you need to.

Please also keep it friendly for GitLab, since this looks like it will be used there, and make sure the README and example env files are actually useful so someone can get it running quickly.