Site Profiler: mobile tweaks

[javierarce]

Two mobile issues reported by @simison (thanks!):

The main CTA and the backlink in the inner page are currently displayed side by side:

To avoid those elements being compressed like that, we should display them on top of each other

And the heading of the banner at the bottom is too big; we should use a smaller font size (30px / 1.875rem).

Figma file: LhioRMwirFL3WNKErGOzvy-fi-505_200