.yk-backtop{position:fixed;background-color:#FFF;width:40px;height:40px;border-radius:50%;color:#2E63FD;display:-ms-flexbox;display:flex;-ms-flex-align:center;align-items:center;-ms-flex-pack:center;justify-content:center;font-size:20px;box-shadow:0 0 6px rgba(0,0,0,.12);cursor:pointer;z-index:5}.yk-backtop:hover{background-color:#F2F6FC}