#banner{
	position: relative;
	height: 635px;
}
#banner ul{
	height: 100%;
}
#banner li{
	display: none;
	position: absolute;
	left: 0;
	top: 0;
	width: 100%;
	height: 100%;
	overflow: hidden;
	text-align: center;
}
#banner li img{
	position: absolute;
	left: 50%;
	top: 0;
	margin-left: -960px;
}

#banner .btn{
	display: none;
	width: 50px;
	height: 50px;
	background: #666;
	opacity: .5;
	position: absolute;
	top: 40%;
	color: #fff;
	font-size: 30px;
	text-align: center;
	line-height: 30px;
	z-index: 20;
}
#banner .prev{
	left: 0;
}
#banner .next{
	right: 0;
}
.banner_nav{position: absolute; overflow: hidden; width: 100%; bottom: 5%; left: 0; text-align: center; z-index: 20; text-align: center;}
.banner_nav span{
	display: inline-block; 
	margin: 0 10px; 
	width: 16px; 
	height:16px;
	cursor: pointer; 
	background: #fff;
	border-radius: 50%;
}
.banner_nav .active{
	background: #ff9e00;
}