Joshua Hibbert:

This is a neat little trick that I stumbled upon when play­ing around with a CSS exper­i­ment a few months ago. Basically, by using mul­tiple box-shadows, you can draw com­plex images with only a single ele­ment. As you may know, I’m a big fan of semantic markup, and I really don’t like using extra ele­ments just for styl­ing, so I was very happy with this discovery!

Nice trick!