MidhaTahir/InstagramClone ? reverse-engineered prompt

Build me an Instagram style web app where people can sign up, log in, and share photo posts.

I want a clean social feed with a simple Instagram like look, using React and Firebase so the app can handle authentication, storing posts, and uploading images. Users should be able to create a post with a caption and image, see their posts appear in the feed, and browse other posts in a smooth, modern layout. Make it feel polished and easy to use, with a responsive design that works well on desktop and mobile.

Please also add the basic account flow, a header or navigation area, and a nice styled interface using Material UI. If anything is unclear, look up current Firebase or React docs online if you need to.