Secret sauce from "Checkboxes and the ridiculous things you can do with them"

gistfile1.css

/* 
http://thecssninja.com/talks/ridiculous_checkboxes/#/ 
*/

/* Off */
    input[type="checkbox"] ~ div {
        // Fancy styles
    }

 /* On */
    input[type="checkbox"]:checked ~ div {
        // Fancy styles
    }