<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<style>
body {
display: flex; /* 使用Flex布局 */
justify-content: center; /* 水平居中 */
}
.ball {
width: 100px;
height: 100px;
border-radius: 50%; /* 把正方形变成圆形*/
background-color: #FF5722; /* 设置颜色为橙色*/
animation: bounce 0.5s cubic-bezier(.5,0.05,1,.5);
animation-direction: alternate; //alternate(2,4,6)反向动画
animation-iteration-count: infinite;
}
@keyframes bounce {
from { transform: translate3d(0, 0, 0); }
to { transform: translate3d(0, 200px, 0) rotateX(45deg); }
}
</style>
<body>
<div class="ball"></div>
<script>
</script>
</body>
</html>
原文：http://www.cnblogs.com/jiebba/p/7602668.html