.bg {
  width: 10rem;
  margin: 0 auto;
  overflow: hidden;
  position: relative;
  height: 16.01rem;
  background: url(../images/banner.jpg) no-repeat;
  background-size: 100% 100%;
}
.bg-long {
  width: 10rem;
  margin: 0 auto;
  overflow: hidden;
  position: relative;
  height: 17.78rem;
  background: url(../phone/bg-long.png) no-repeat;
  background-size: 100% 100%;
}
.banner {
  width: 7.42rem;
  height: 9.14rem;
  background: url(../phone/phone.png) no-repeat;
  background-size: 100% 100%;
  margin: auto;
  margin-top: 3.5rem;
}
.down-btn {
  position: absolute;
  width: 4.7rem;
  height: 1.4rem;
  /* background: pink; */
  top: 13.8rem;
  left: 2.7rem;
  /* background: url(../phone/down-btn.png) no-repeat;
  background-size: 100% 100%; */
 
}