Using :has() as a CSS Parent Selector and much more | WebKit
A terrific tour of just some of the fantastic ways you can use :has() in CSS.
The section on using it with sibling selectors blew my mind:
How often have you wanted to adjust the margins on a headline based on the element following it? Now it’s easy. This code allows us to select any h2 with a p immediately after it.
h2:has(+ p) { margin-bottom: 0; }Amazing.