It's a pity that the currently good pure CSS frameworks seem to only have Bootstrap left standing. This leaves me with fewer choices, as someone who uses Ruby On rails / Django and doesn't want to use the new generation of frontend CSS solutions.

I might need a CSS solution that is less React-heavy, one that provides basic components and a user-friendly style system; I just need to include a CSS file (possibly a helper JS file) and then I can make style adjustments in my own application CSS.

Do you have any recommendations?