.big_img{position: fixed;z-index: -1;opacity: 0;background: rgba(0,0,0,0.9);width: 100%;height: 100%;top:0;left:0;}
 .big_img .swiper-container2 {position: relative;width: 100%;height: 100%;}
 .big_img .swiper-container2  .swiper-wrapper{width: 100%;height: 100%;}
 .big_img .swiper-slide{width: 100%;height: 100%;display: table}
 .big_img .swiper-slide .cell{width: 100%;;height: 100%;display: table-cell;vertical-align: middle;text-align: center;}
 .big_img .swiper-slide img{max-width: 90%;max-height: 80%;margin:0 auto;}
 .big_img .swiper-pagination2{position: absolute; top:0.2rem;text-align: center;width: 100%;}
 .big_img .swiper-pagination2 span{margin:0 0.05rem;}