body {
 
  background: rgb(0, 0, 0);
  overflow: hidden;
  margin: 0;
  /* background-color: #000 !important; */
}
.cd-top-box {
    position: fixed;
    width: 48px;
    height: 48px;
    bottom: 50px;
    right: 10px;
    z-index: 2;

}
.cd-top {
    background: url(https://image.leevast.cn/return.svg) no-repeat center 50%;
            height: 48px;
        width: 48px;
        right: 50px;
        bottom: 50px;
        display: inline-block;
    position: fixed;
    overflow: hidden;
    text-indent: 100%;
    white-space: nowrap;
    visibility: hidden;
    opacity: 0;
    -moz-transition: opacity .3s 0s, visibility 0s .3s;
    transition: opacity .3s 0s, visibility 0s .3s;
}
.cd-top.cd-is-visible {
    visibility: visible;
    opacity: .8;
}
.cd-top.cd-is-visible, .cd-top.cd-fade-out, .no-touch .cd-top:hover {
    -webkit-transition: opacity .3s 0s, visibility 0s 0s;
    -moz-transition: opacity .3s 0s, visibility 0s 0s;
    transition: opacity .3s 0s, visibility 0s 0s;
}