CSS3 box-shadow:

浏览器参照基准：Firefox4 and Later, Chrome5 and Later, Safari5 and Later, Opera10.53 and Later, IE9.0 and Later

凹陷阴影效果：

.shadow-cave{
	float:left;
	position:relative;
	box-shadow:0 10px 5px rgba(0,0,0,.3);
}
.shadow-cave:after{
	position:absolute;
	bottom:-29px;
	left:0;
	overflow:hidden;
	background:#fff;
	width:100%;
	height:15px;
	content:'';
	border-radius:50%;
	box-shadow:0 -10px 5px #fff;
}

CSS3将开启“少图”web新时代