CSS is traditionally used to create rollover effects with two or more images for menus and other elements. Menus can use on, off, or visited images to signify the state of the menu. Typically menus are created using multiple background images, however. The problem with this method is that it doubles the necessary HTTP requests and can cause flickering problems when the "off" image is not preloaded.

Everything old is new again, and though the rise of 3D games has made sprite maps obsolete, the concurrent rise of mobile devices with 2D gaming capabilities have brought them back into vogue. And now, with a bit of math and a lot of CSS, we’re going to take the basic concept and apply it to the world of web design.

While there are many characteristics of your content that are in the algorithmic calculations, there are a few that consistently hold relatively high priority and thus will be the focus of this article. These are:

•  Heading Tags
• Special Text (bold, colored, etc.)
• Inline Text Links
• Keyword Density