heysagnik/screenREC — reverse-engineered prompt

Build me a clean, minimal web app called ScreenREC that lets someone record their screen from the browser with no ads, no sign in, no tracking, and no time limits.

The user should be able to choose a screen, window, or tab, turn microphone audio on or off, add their webcam as a picture in picture overlay, drag the camera around, and switch between a normal PiP style and a circular camera style. Add simple controls for start, pause, resume, stop, mic, camera, and screen sharing. Include keyboard shortcuts for pause, mic, camera, and screen controls.

After recording, let the user preview the video and download it as WebM, with an option to export MP4 using a small backend conversion service. Keep everything privacy first, with recording handled locally in the browser as much as possible.

Use a modern React and TypeScript setup with a polished responsive desktop UI. Mobile can show a friendly unsupported message. Look up current browser recording APIs if needed.