<div></div>
<!-- 样式 -->
<style>
/*定义动画*/
@keyframes myfirst
{
0% {background: red;width: 20%;}
25% {background: yellow;}
50% {background: blue;}
100% {background: green;width: 100%;}
}
div
{
width: 200px;
height: 200px;
background-color: #999;
/*执行动画*/
animation: myfirst 5s;
}
</style>