Offline — Référence de design web et prompt

# Prompt: "offline" power-button footer

Build a single-file **website footer** for a fictional digital-wellbeing product, **offline** ("Everything you need to know before you finally log off"). Use plain HTML, CSS and vanilla JS, with no framework and no build step. The footer is one full-bleed cinematic scene: a small beige vintage all-in-one computer (generic, no brand logo) on a grassy hill under a blue sky. The wordmark's "o" is a power button. Clicking it takes the scene offline: the sky turns to night, the CRT collapses to a point, and that last point of light flies up into the power-o.