CSS Library: Links & Buttons: CSS3 demos: Here
3D Depressible Button
Author: Dynamic Drive
CSS can be used to really jazz up a plain looking link and create an awesome "call to action" button, as in the case of our 3D depressible button here. It uses CSS2 pseudo element to add a lower 3D side to the link, and CSS3 shadows and transition to complete the look. To overcome a severe limitation of Google Chrome and Safari at the time of writing not supporting CSS3 transitions on pseudo elements, we use the "inherit" technique as described here, so the 3D side of the button is animated when the user presses down on the button.
Note that the default "depth" of the 3D effect is 12px. If you need to increase or decrease this value, change the "12px" value that occurs 3 times in the CSS.