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; /* Firefox */ animation:myfirst 5s; /* Safari and Chrome */ animation:myfirst 5s; /* Opera */}@keyframes myfirst{ 0% {background:red;} 25% {background:yellow;} 50% {background:blue;} 100% {background:green;}}@-moz-keyframes myfirst /* Firefox */{ 0% {background:red;} 25% {background:yellow;} 50% {background:blue;} 100% {background:green;}}@-webkit-keyframes myfirst /* Safari and Chrome */{ 0% {background:red;} 25% {background:yellow;} 50% {background:blue;} 100% {background:green;}}@-o-keyframes myfirst /* Opera */{ 0% {background:red;} 25% {background:yellow;} 50% {background:blue;} 100% {background:green;}}</style></head><body><div></div><p><b>注释：</b>当动画完成时，会变回初始的样式。</p><p><b>注意:</b> 该实例在 Internet Explorer 9 及更早 IE 版本是无效的。</p></body></html>