For instance, if a class defines a width of 100 pixels, all DIVS referencing that class will be 100 pixels wide. You can override a DIV's CSS class definition by updating the DIV's HTML code.

Wybiral was able to do this by creating a grid of HTML DIVs that utilize CSS :hover selectors to request a new background image when your mouse moves over a box on the grid.

We’ve seen numerous server-side approaches and they always seem to obfuscate the powerful trio of HTML, JavaScript, and CSS, which continues to win out in the end. Maybe this time will be different.