代码示例：（标识：cssref_anim_padding-right）
<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
background-color: lightblue;
border: 1px solid black;
animation: mymove 5s infinite;
}
@keyframes mymove {
50% {padding-right: 150px;}
}
</style>
</head>
<body>
<h1>padding-right 的动画效果：</h1>
<p>逐渐将右内边距从 0px 改为 150px，然后再改回 0px：<p>
<div id="myDIV">
Shanghai is one of the four direct-administered municipalities of the People's Republic of China. Welcome to Shanghai! ...
</div>
<p><b>注释：</b>CSS 动画在 Internet Explorer 9 以及更早版本中不起作用。</p>
</body>
</html>
