.ek-backtop {
  position: fixed;
  width: 50px;
  height: 50px;
  left: 50%;
  bottom: 20px;
  margin-left: 520px;
  background-color: #fff;
  .iconfont {
    font-size: 38px;
    line-height: 50px;
    color: #999999;
  }
  span {
    display: none;
    width: 100%;
    height: 100%;
    padding: 4px 8px;
    line-height: 20px;
    cursor: pointer;
    color: #fff;
  }
  &:hover {
    background-color: $btn-color-blue;
    .iconfont {
      display: none;
    }
    span {
      display: inline-block;
    }
  }
}