Brunonunes06/Safe-Bite — reverse-engineered prompt

Build me a Safe Bite web app in Portuguese for people who want to scan or check foods and understand nutrition and allergy risks before they eat.

It should have a clean landing page, login and signup, a dashboard, profile, settings, help, privacy, history, scanner pages, and a contact area. Users should be able to scan or upload food information, see a simple nutritional analysis, and keep a history of what they checked. Include dark mode, responsive navigation, loading states, and clear account indicators.

Add premium plans with a payment page using PIX through Mercado Pago. The payment flow should generate a PIX QR code, handle subscription upgrades, and use a backend with proper environment variables, JWT login, MongoDB, CORS, input validation, and secure webhook handling. Please keep secrets out of the code and use example env files.

Use plain HTML, CSS, JavaScript, Node, and Express like this project does. Look up current Mercado Pago docs online if you need to.