Revisit CSS solution

[howardchung]

Five years after #1189, I'm not such a big fan of styled-components:

• It doesn't work well with syntax highlighting
• It's a weird amalgamation of JS and CSS that loses out on tooling for both

It's probably too much work and not enough benefit to actually migrate everything, but if I were redoing this I'd probably just use CSS modules. Not sure what the state of the art is, so please chime in with thoughts!

[talal-najam]

Agreed! I'd vote for CSS modules with Scss. Shared styles, theme / vars files, mixins and other scss goodies along with scoped module styles would be pretty clean in my opinion.

Alternate options could be Tailwind but I imagine that's not really everyone's cup of tea. Keen to hear what others think.