Force background color to white, not transparent

[stoyle]

Should fix #140

[pearofducks]

This breaks hover styling on the checkbox.

[stoyle]

Oh wow, that's interesting! Good catch.

Seems specificity is higher on the "regular" ::before styling, than with hover. Creating a custom hover style for this case should be even more specific... But too complicated for such a small thing?

We can fix this with a custom selector in our podlet.

[stoyle]

This fixes it for us: https://github.schibsted.io/finn/extended-profile-podium/commit/1b5e2f2bfa6cc43770e25498c1ab509612ae37ab

I still think this should live in fabric, not in our repo. But that is of course up to the fabric team.

By the way, the check mark is visible when hovering, but I guess that's a feature 😄