html{
font-size:10vw;
}
.backToPc,
.backToMobile {
  width: 1.33333333rem;
  height: 1.33333333rem;
  border: solid 1px #d7d7d7;
  border-top-left-radius: 0.66666667rem;
  border-bottom-left-radius: 0.66666667rem;
  background-color: #ebebeb;
  border-right: none;
  position: fixed;
  right: 0;
  bottom: 2rem;
  z-index: 99999;
  padding: 0;
  margin: 0;
  transition: .5s all;
}
.backToPc span,
.backToMobile span {
  text-indent: -1978px;
  overflow: hidden;
  width: 0.93333333rem;
  height: 0.93333333rem;
  background: url(../images/backToDesk.png) no-repeat center center #ffffff;
  background-size: 50%;
  display: block;
  border-radius: 50%;
  margin: 0.2rem;
}
.backToMobile span {
  background: url(../images/app.png) no-repeat center center #ffffff;
  background-size: 50%;
}