xxxxxxxxxx<html><head><meta charset="utf-8"> <title>W3Cschool教程(w3cschool.cn)</title> <style> div{ width:100px; height:100px; background:red; transition-property: width; transition-duration: 2s; transition-property: width; /* Safari */ transition-duration: 2s; /* Safari */}div:hover{ width:300px;}</style></head><body><p><b>注意:</b> 该属性不兼容 IE9以及更早版本的浏览器.</p><div></div><p>鼠标移动在块上查看动画效果.</p></body></html>