HTML
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>笔下光年</title>
</head>
<body>
<p>逐步改变 max-width, 从 "none" 到 "800px":<p>
<p><strong>注意:</strong> min-width 属性会覆盖 width 属性。</p>
<div id="myDIV">
<p>This DIV element has a pre-defined width: 50%.</p>
<p>An animation will gradually change the min-width to 800 pixels.</p>
</div>
<p>min-width 属性支持动画效果。</p>
<p><b>注意：</b>Internet Explorer 9 及更早 IE 版本不支持 CSS 动画。</p>
</body>
</html>
CSS
#myDIV {
width: 50%;
background-color: lightblue;
overflow: auto;
border: 1px solid black;
-webkit-animation: mymove 5s infinite; /* Chrome, Safari, Opera */
animation: mymove 5s infinite;
}
/* Chrome, Safari, Opera */
@-webkit-keyframes mymove {
50% {min-width: 800px;}
}
/* Standard syntax */
@keyframes mymove {
50% {min-width: 800px;}
}