Sticky bottom call-to-action — max one per biolink.
The Fixed CTA block adds a persistent bar at the bottom of the screen while visitors scroll.
- Add block → Fixed CTA (Standard category).
- Set brand label (left), button text (right), and destination URL.
- Adjust opacity so content behind remains readable.
Limit: maximum 1 fixed CTA per biolink. It respects mobile safe areas (notches).