Rules for great CSS

Keep it ‘flat’ – nested css means possible breaking design when elements get moved. Only nest when specificity is necessary.
Assume you will repeat your styles – styling a box with text in it? Rather than styling that box alone, create a class that contains the styles for that box, so when you want to use it again, all you need to do is add the class. A well designed webpage will have similar styles that are repeated anyways.
more to come…