I need a mobile-responsive web app that lets visitors sign in through the Steam API, automatically pulling their SteamID so they can enter free sweepstakes with a single click. The core build should feel snappy on phones first, then scale gracefully to desktop. Key flow • User arrives, taps “Sign in with Steam,” and is authenticated via OpenID. • Once logged in, the site tracks each entry they make, stores it under their account, and presents a simple profile page that shows only their sweepstakes history. Sweepstakes engine An automated job must close each giveaway at the scheduled time, randomly select a winner from valid entries, and fire off both an on-site and email (or Steam message if feasible) notification. I also want an admin view where I can start a new giveaway, specify the end date, and see live entry counts. Monetisation Video ads are the sole revenue stream, so placements need to be integrated without tanking load times or breaking the mobile layout. Pre-built ad tags will be supplied; just leave reliable hooks and test that they don’t interfere with sign-in or drawing winners. Preferred stack I’m open, but a modern JavaScript framework (React, Vue or Svelte) on the front end and a lightweight Node or Python back end with a relational database feels right. Security, rate-limit protection on the Steam API and clean code comments are expected. Deliverables • Fully deployed, mobile-first web app with Steam login, entry tracking, automated winner selection and winner notifications live on a test subdomain • Source code in a private Git repo with a concise README for local setup • Brief hand-off session (recorded or live) walking through the admin panel and cron/worker configuration If you’ve shipped Steam-integrated projects before or have a strong grip on OAuth/OpenID flows and responsive UI, this should be a straightforward build. Let me know the framework you’d choose and any similar work you can show.