"Modern CSS only column hover" by Sten Hougaard
https://codepen.io/netsi1964/pen/dyaPrPK
(Also, isn't it amazing how you can chuck a checkbox anywhere in the DOM, then do like body:has(.checkbox:checked) and *do anything you want* to style the page based on if it's checked or not? Jeepers.)

https://twitter.com/CodePen/status/1732203241390395532