There's a lot you can do with CSS Selectors. You don't need to let them get too complicated, but the combinations can allow you to do some cool things programmatically. In the example below, I've demonstrated a few of those techniques.

NB: Don't feel like you have to master all of these (this is a tiny fraction of what is out there...). Just pick a couple and figure them out. (It makes sense to experiment at length with each of my examples, below. Don't just look at my single example and assume that will mean anything to you later).

Visit the W3School's Selector Tester to see some of them in action.

See the Pen MiamiGuidelines_furtherExamples by Garrison LeMasters (@Garrison) on CodePen.