#overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 9999;
}

#overlay img {
  max-width: 80%;
  max-height: 80%;
  background: white;
  box-shadow: 0 0 20px black;
}