I'd second doing this tutorial. I think what they have is terrible for somebody brand new to CSS, but for a developer who has worked with CSS and still not quit

I'd second doing this tutorial. I think what they have is terrible for somebody brand new to CSS, but for a developer who has worked with CSS and still not quite put it all together, this tutorial is great. For me one of the keys to "getting" CSS, and I think is the hardest, worst part of CSS, is understanding all of the implicit contexts that are generated. For example, elements have positioning roots. Nowhere does this word even show up in the CSS language, you have to know that it's created whenever an element has a position that is not static. Similarly elements have a stacking context which is hugely important to understanding z-index and transform. Again never explicitly mentioned, inststead stacking contexts are implicitly created by a variety of actions like setting an element's background color to anything with a non-zero opacity.