#spinner-back, #spinner-front {
  position: fixed;
  width: 100vw;
  transition: all 1s;
  visibility: hidden;
  opacity: 0;
}
#spinner-back {
  z-index: 9999;
  height: 100vh;
  background: rgba(0, 0, 0, 0.7);
}
#spinner-front {
  z-index: 999;
  color: #fff;
  text-align: center;
  margin-top: 50vh;
  transform: translateY(-50%);
}
#spinner-back.show, #spinner-front.show {
  visibility: visible;
  opacity: 1;
}