[cantlin]

My understanding is that performance is a negligible factor next to maintainability when writing CSS in virtually all cases. The best post I've seen on the subject is by Steve Souders[0], which does include some numbers.

[0] http://www.stevesouders.com/blog/2009/03/10/performance-impa...

Further reading:

http://csswizardry.com/2011/09/writing-efficient-css-selecto... https://developer.mozilla.org/en-US/docs/CSS/Writing_Efficie...