/*banner轮播图*/
.banner{margin:0 auto;position:relative; overflow:hidden;}
.swiper-container{

}
.swiper-slide img{
 width: 100%;
 height: auto;
}
.banner .arrow_btn{display: none; position: absolute; top: 50%; z-index: 2;width: 40px;height: 75px;margin-top: -50px; border-radius: 3px; opacity:0.5; text-indent: -9999px; background-repeat: no-repeat; transition: opacity .2s linear 0s;cursor: pointer;}
.banner .arrow-left{ left: 5px; background:url(banner_btn.png) no-repeat left bottom;}
.banner .arrow-right{ right: 5px; background:url(banner_btn.png) no-repeat right bottom;}