<html>
<head>
<style>
div {
width: 100px;
height: 100px;
background: red;
position: relative;
animation: mymove 5s infinite;
}
@keyframes mymove {
0% {top: 0px; background: red; width: 100px;}
100% {top: 200px; background: yellow; width: 300px;}
}
</style>
</head>
<body>
<h1>The @keyframes Rule</h1>
<div></div>
</body>
</html>