/**app.wxss**/
.container {
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 200rpx 0;
  box-sizing: border-box;
}

.imgBack {
  position: relative;
  /* left: -50%; */
}

.imgBack .img {
  width: 100%;
  height: 100%;
  /* background-size: 100% 100%; */
  position: fixed;
  z-index: -1;
}