I believe the relevant lines are @-webkit-keyframes ball { 0%, 100% { left:30px; top:107px } 30% ... and -webkit-animation: player2 4s linear 0 i

I believe the relevant lines are @-webkit-keyframes ball { 0%, 100% { left:30px; top:107px } 30% ... and -webkit-animation: player2 4s linear 0 infinite normal; which define the animation keyframes and parameters. See the webkit blog for information on how it works: http://www.webkit.org/blog/324/css-animation-2/ http://www.webkit.org/blog/324/css-animation-2/