reader/components/medal/index.wxss

.mediaBox {
  position: fixed;
  top: 0px;
  left: 0px;
  width: 100vw;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.35);
}
.mediaBox .media {
  width: 470rpx;
  height: 608rpx;
  background-color: #FEF2C7;
  border-radius: 20rpx;
}