#lightbox-overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0, 0, 0, 0.9);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 10000;
  flex-direction: column;
}
#lightbox-image {
  max-width: 90%;
  max-height: 80%;
  border-radius: 8px;
  box-shadow: 0 0 20px #000;
}
#lightbox-prev, #lightbox-next, #lightbox-close {
  color: white;
  font-size: 40px;
  cursor: pointer;
  user-select: none;
  position: absolute;
  z-index: 10001;
}
#lightbox-prev { left: 20px; top: 50%; transform: translateY(-50%); }
#lightbox-next { right: 20px; top: 50%; transform: translateY(-50%); }
#lightbox-close { top: 20px; right: 30px; font-size: 50px; }