.wrap {
  position: absolute;
  left: 0; top: 0; right: 0; bottom: 0;
  background: #000;
}
.cam {
  position: absolute;
  left: 0; top: 0;
  width: 100%;
  height: 100%;
}
.tip {
  position: absolute;
  left: 0; right: 0;
  bottom: 80rpx;
  text-align: center;
  color: #fff;
  font-size: 13px;
  z-index: 2;
}