.screen {
	width: 100px;
	height: 100px;
	background-color: red;
	position: relative;
	-webkit-animation: myfirst 5s linear 2s infinite alternate; /* Safari 4.0 - 8.0 */
	animation: myfirst 5s linear 2s infinite alternate;
	}
/* Safari 4.0 - 8.0 */
@-webkit-keyframes myfirst {
	0%	{background-color:red; left:0px; top:0px;}
	25%	{background-color:yellow; left:200px; top:0px;}
	50%	{background-color:blue; left:200px; top:200px;}
	75%	{background-color:green; left:0px; top:200px;}
	100% {background-color:red; left:0px; top:0px;}
	}
/* Standard syntax */
@keyframes myfirst {
	0%	{background-color:red; left:0px; top:0px;}
	25%	{background-color:yellow; left:200px; top:0px;}
	50%	{background-color:blue; left:200px; top:200px;}
	75%	{background-color:green; left:0px; top:200px;}
	100% {background-color:red; left:0px; top:0px;}
	}