Ditmemayngu/otpweb36 — reverse-engineered prompt

Build me a small Python web app called otpweb36. I want it to run on Vercel and use a JSON file of domains as its data source.

The site should let someone type or paste a domain or email address, check it against domains.json, and show a clear result like allowed, blocked, or not found. Keep the page very simple and mobile friendly, with one input box, a check button, and a readable result area.

Also add a basic health route and a JSON API route so other tools can query the same check. Make sure app.py starts the web app cleanly, requirements.txt has only what is needed, and vercel.json is set so deployment works.

If anything is unclear because there is no README, choose the simplest working behavior and keep the code easy to edit later.