.haha-backToTop {
  height: 2.81rem;
  position: fixed;
  width: 2.81rem;
  background: url("https://cdn.xueyuan.xiaobao100.com/shield/image/topbtn.png") no-repeat center;
  background-size: 100%;
  right: 1rem;
  bottom: 4.69rem;
  z-index: 1010; }