schoolwisdoms-student-mp/pages/demo/demo.wxss

.close-camera{
  position: absolute;
    z-index: 2;
    color: #FFF;
    top: 20rpx;
    right: 20rpx;
    font-size: 32rpx;
    padding: 25rpx;
}
.camera-view{
  position: absolute;
    top: 0;
    width: 750rpx;
    left: 750rpx;
}