Very nice guide, I wish the actual spec were laid out so clearly. (The spec isn't bad, it just doesn't have it all in one handy list like this). The sidebar wa

Very nice guide, I wish the actual spec were laid out so clearly. (The spec isn't bad, it just doesn't have it all in one handy list like this). The sidebar waterfall illustration was cool, and I liked that it didn't move when I scrolled so I could keep referencing it. That's useful. The little inline quizzes were unexpected, but did help me double check that I was understanding the explanations.