Floating WhatsApp button

The button stays at the bottom right of the screen, on mobile and desktop alike. It opens a welcome bubble: who answers, the usual reply time, three common topics that fill in the message in one click, and an editable field. The Continue on WhatsApp link is a plain wa.me link built from the message: no WhatsApp script or cookie is loaded before the click, which keeps the page light and makes GDPR simpler than with third-party widgets. Replace the number (digits only, country code without the leading zero) and the texts, and you are done.

Accessibility: a native button with aria-expanded and aria-controls, accessible name "Nous écrire sur WhatsApp", focus moved to the message on opening, closing with Escape or the Close button with focus returned, topics as aria-pressed buttons, a labelled field, a link that announces it opens a new tab, targets of at least 44 px, 3 px focus outlines, AA contrast measured in light and dark, and no animation with prefers-reduced-motion. Without JavaScript the button stays a link that opens WhatsApp with the default message.