I really hate CSS frameworks, so I can't recommend any.
Even worse, flat shapes look much better to me than all that glassy-shadowy crap Apple adores.
On the other hand, Bootstrap lookalikes are a tremendous bore nowadays, for the same reason most of CSS frameworks end up being a bore. Too many people using them, too many barely customizing them. And customization only goes so far.
CSS is great nowadays; and styling controls is really easy. Even more since we have nesting.
I find it even relaxing.
@pointlessone
Recommended reading:
https://lyra.horse/blog/2025/08/you-dont-need-js/