Modernizr

Modernizr: "What is Modernizr?

Have you ever wanted to do if-statements in your CSS for the availability of cool features like border-radius? Well, with Modernizr you can accomplish just that! The syntax is very intuitive, too:

.multiplebgs div p {
/* properties for browsers that
support multiple backgrounds */
}
.no-multiplebgs div p {
/* optional fallback properties
for browsers that don't */
}"