.totop{z-index: 9999;background: url("/Public/Home/Index/totop.png");width: 45px;height: 45px;position: fixed;left:50%;bottom:110px;margin-left: 556px;  }
    @media screen and (max-width: 800px) {
        .totop{right: 0;left:auto;margin-left: 0;}
    }