.simple_gallery_lightbox_wrapper {
  position: fixed;
  width: 100vw;
  height: 100vh;
  left: 0;
  top: 0;
  background: rgba(0,0,0,0.80);
  cursor:pointer;
  display: none;
  z-index: 9999;
}

.simple_gallery_lightbox_wrapper img {
  position: absolute;
  width: 80%;
  height: auto;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}