How nth-child Works

There is a CSS selector, really a pseduo-selector, called nth-child. Here is an example of using it: ul li:nth-child(3n+3) { color: ccc; } What the above CSS does, is select every third list item inside unordered lists. That is, the 3rd, 6th, 9th, 12th, etc. But how does that work? And what other kinds of things can [...] http://tinyurl.com/yfm7wq2