xxxxxxxxxx<html><head><meta charset="utf-8"> <title>W3Cschool教程(w3cschool.cn)</title> <style> div{ width:100px; height:100px; background:red; animation:myfirst 5s; animation:myfirst 5s; /* Safari and Chrome */}@keyframes myfirst{ from {background:red;} to {background:yellow;}}@-webkit-keyframes myfirst /* Safari and Chrome */{ from {background:red;} to {background:yellow;}}</style></head><body><p><b>注意:</b> 该实例在 Internet Explorer 9 及更早 IE 版本是无效的。</p><div></div></body></html>