Some useful css optimisation articles

Some great tips in there when building your styles, every rule you write affects the speed of the page!

CSS optimisation
http://perfectionkills.com/profiling-css-for-fun-and-profit-optimization-notes/
http://csswizardry.com/2012/11/code-smells-in-css/

Animating css sprites
http://buildnewgames.com/dom-sprites/