Here are some references to the vocabularly of HTML. Frankly, it’s hard to see much structure here. It seems like a lot of special rules.
- declartion: property and value
- HTML as a tree — Ancestor, Descendant, Parent, Child, Sibling
- Class vs ID
- the box model
- HTML5 and its semantics elements
- Appendix A: Essential CSS
Something to do
Complete the MDN CSS tutorial.