.intro {
  margin: 20rpx auto;
  width: 80vw;
  height: calc(100vh - 40rpx - constant(safe-area-inset-bottom));
  height: calc(100vh - 40rpx - env(safe-area-inset-bottom));
  text-align: center;
  background-color: skyblue;
}

• 代码片段：https://developers.weixin.qq.com/s/yfnOtVmi7YlO

异常版正常版：