While refreshing my knowledge about CSS I noticed the CSS box model is explained in the following order:
Borders
Margins
Padding
Height/width
Box model
Outline
First all components of the box model are explained in depth and afterwards a general overview is given (5: box-model). For me as a reader this was confusing, since I didn't get the main concept until reading the "box-model" page and actually had to go back and reread the margins/padding section to thoroughly understand the system.
I therefore suggest changing the explanation order to: