#lightbox {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  visibility: hidden;
  opacity: 0;
  transition: visibility 0s, opacity 0.3s;
}

#lightbox.visible {
  visibility: visible;
  opacity: 1;
}

#lightbox-content {
  max-width: 90%;
  max-height: 90%;
}

#lightbox-image {
  max-width: 100%;
  max-height: 100%;
}

.hidden {
  display: none;
}