smit-prajapati-24/traffic-congestion ? reverse-engineered prompt

Build me a web app called SmartFlow AI that shows live traffic congestion in a cool, modern way. The main screen should have an interactive 3D crossroads scene with moving vehicles, traffic lights, and congestion that feels animated and real time. I want a dark, polished landing page with smooth motion and a clear way for users to sign up, log in, and access the app securely.

Please include a simple auth flow backed by a Node and Express API with MongoDB, using JWT for login sessions. Also add a CCTV style page that can show a live webcam feed with a helmet detection overlay coming from a separate Python service if it is available. Make the UI responsive, clean, and easy to use, with a futuristic traffic control feel.

Set it up so I can run the frontend and backend locally, and if you need anything from current docs, look it up online first.