I've read Duckett's book (Amazon bestseller) and its just syntax. Also, I've read the Atomic CSS design and BEM methodologies, and while those come close to what I want, I'm looking for a more detailed treatment. To give an obvious example of what I'm looking for- I would say, use margins to separate multiple instances of same components (among other uses). I wonder if there are books that deal with similar, but non-obvious topics.