No idea what there is to learn about HTML, it's CSS that's the problem. I've never found a resource that explained CSS well. CSS still surprises me almost dail

No idea what there is to learn about HTML, it's CSS that's the problem. I've never found a resource that explained CSS well. CSS still surprises me almost daily. I'll be probably fluent in Haskell before I ever get CSS. What would really help me is having the source code of a well-written, high-level CSS rules engine - written for educational purposes, not for performance.