Backport #30828 by @silverwind
Makes it easier to use because you see which square is currently
hovered:
<img width="314" alt="Screenshot 2024-05-02 at 15 38 20"
src="https://github.com/go-gitea/gitea/assets/115237/3a15dad1-2259-4f28-9fae-5cf6ad3d8798">
I did try a `scoped` style for this, but that did not work for some
reason.
Co-authored-by: silverwind <me@silverwind.io>