I'm surprised no one mentioned Lea Verou's "CSS Secrets" [0]. Most books I've read will give some depth at how aspects of CSS work, or recommend a best practice, but Verou's work is the only one I've seen that sees using CSS as an engineering solution. The book is a collection of problems, e.g. "how to add multiple borders?", And the shows different ways to solve the problem given the available CSS. Each solution discussed trade-offs, constraints, etc.

It will go the farthest in teaching you how to think about CSS

[0] https://www.oreilly.com/library/view/css-secrets/97814493727...