Facebook Icon in CSS Using a Single Div

I was inspired by the idea that you can make a wide range of shapes using only CSS on a single div after reading this css-trics.com page. I created the Facebook Icon using a single div:

#f {
width: 100px;
height: 80px;
background-color: #3B5998;
border-bottom: 20px solid #6d84b4;
position: relative;
#f:before {
position: absolute;
top: 15px;
right: 15px;
border: 15px solid #fff;
border-bottom: none;
border-right: none;
border-top-left-radius: 15px;
width: 15px;
height: 65px;
content: "";
#f:after {
position: absolute;
top: 44px;
left: 43px;
height: 15px;
width: 42px;
background-color: #fff;
content: "";

It works in Firefox 5, Chrome 13, and Safari 5.1. It works in IE8, but the “f” is not rounded. See the JS Fiddle version.