Build me a MEETAMASK mask. MEETAMASK is a macOS virtual camera: it runs a small web page off-screen, draws my webcam plus an effect, and streams the result into Zoom / Google Meet / Teams. Your job is to write that web page. ## Output Return ONE complete, self-contained `index.html` in a single code block — nothing else. It must run with ZERO external files and ZERO network. ## Hard rules (the mask runs in a locked sandbox — break these and it renders black) 1. No network, no CDN. No ` Once you give me the file: I save it as index.html, then in MEETAMASK I click "Add mask" and pick it.