I don't think that's true. Hackers need to know CSS too and I am always very surprised at how little most programmers know abotu CSS.
I thought this smashing post was one of the better explanations of CSS selectors that I've seen.
If you want to learn about the specificity values of CSS selectors, Specificity Wars is a much better read.
http://www.stuffandnonsense.co.uk/archives/css_specificity_w...
Re:Taming Advanced CSS Selectors
by Devils-Avacado on Monday August 17, 2009 @03:19PM
(#768842)
Yeah, but the W3 site is so ugly...
http://www.w3.org/TR/2001/CR-css3-selectors-20011113/#select...
I don't generally engage in meta arguments, but HN is not the place for gentle Smashing Magazine intros to something as basic as CSS selectors. The only thing worth reading from the article might be the specificity portion, but it's usually more than enough to say:
id > class > else