.back-top{position:fixed;width:72px;padding:30px 0;border-radius:42px;right:5%;bottom:calc(50% - 260px);z-index:9999;background-color:#fff;box-shadow:0 0 10px 0 hsla(0,0%,72.9%,.33);text-align:center;font-size:14px;cursor:pointer;color:#222}.back-top img{width:34px;height:34px}.back-top .back-top-kefu{margin-bottom:30px}@media screen and (max-width:1500px){.back-top{right:7px!important}}