A similar list for free to use bootstrap 4/5 themes (like https://bootswatch.com/ but I already know about bootswatch) is in my wishlist.

You could add Framework7[1], a framework that imitates the style of iOS 7+. It’s not as much nostalgia, but can be fun.

https://framework7.io/

nahh this strays too far from the pure css ethos. but thx :)

Thank you.