css3-元素属性动画--transition

<div>123456</div>

div{
width: 200px;
background-color: yellow;
height: 200px;
text-align: center;
line-height: 200px;
opacity: 1;
font-size: 1em;
transition: all 2s;
-moz-transition: all 2s;	/* Firefox 4 */
-webkit-transition: all 2s;	/* Safari 和 Chrome */
-o-transition: width 2s;	/* Opera */
}
div:hover{
width: 300px;
background-color: blue;
height: 400px;
font-size: 2em;
opacity: 0.5;
}