.banner {width: 100%;position: relative;height: 400px;}
.banner_div {width: 100%;position: absolute;height: 400px;z-index: 0;opacity: 0;}
.banner_div:first-child{z-index: 1;opacity: 1;}
.banner_a {width: 100%;display: block;height: 400px;}
.banner_img {width: 100%;height: 400px;position: absolute;}
.banner .banner_button{position: absolute;z-index: 2;bottom: 10px;left: 47%;}/* 在absolute内时left和right只能使用一个 */
.banner .banner_button li {
	width: 12px;
	height: 12px;
	line-height: 18px;
	font-size: 12px;
	background: #fff;
	border: 1px solid #ffffff;
	border-top-style: solid;
	border-right-style: solid;
	border-bottom-style: solid;
	border-left-style: solid;
	color: #666666;
	text-align: center;
	margin-right: 6px;
	font-family: Verdana;
	float: left;
	border-radius: 12px;
	z-index: 1;
	border-style: none;
	-webkit-text-size-adjust: none;
}
.banner .banner_button .banner_button_li_focus{	background: #ff2f2f;}