( margin-top: you start dealing with parents inheriting the margin - which is an old quirk of CSS - it's a side-effect you need to control, so the usage of margin-top should always be avoided and margin-bottom should be the preferred solution owl selector: performance implications - it's fairly bad from a performance POV to use it. Also, we live in a world where we have control over how the layout is generated, we should avoid using generic selectors Source: I've been doing frontend and focused on CSS for over 10 years )