The easiest way to do this is to make the text a child of the div
with the background image. The change to min-size is so that if
the text wraps often enough on narrow screens, the header expands
vertically rather than the text spilling over.
Fixes#3259
This fixes a glitch highlighted in #3259, where the css class stopped applying
when the view was moved to a different controller.
We're moving to having each view responsible for their layout, and commonly having
override classes explicitly in the relevant views. So we can follow that pattern here.
This allows us to have the two sections one above the other on small screens,
with the call to action text first, and then side-by-side above the sm
breakpoint with the cta on the right.
