Essentially you have a container div that sets the lineheight to 1px. Then you have two divs (topShadow and bottomShadow) within that, which have the shadowed text written twice. (Once in black for the text, once in grey behind it for a shadow).
The two divs are indexed so that the top (text) is at a "higher level" than the bottom (shadow), and the shadow is offset to the right and down.