/* Popup overlay */
#image-popup {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: grayscale(1) blur(2px);
  z-index: 9999;
}
/* Active state */
#image-popup.visible {
  display: flex;
}
/* Preview image */
#image-popup img {
  max-width: 92vw;
  max-height: 92vh;
  object-fit: contain;
  box-shadow: 0 10px 40px rgba(0,0,0,0.4);
  user-select: none;
  border: 3px solid var(--color-accent);
  border-radius: var(--radius);
}
/* Close button */
#image-popup .close-btn {
  position: absolute;
  top: 18px;
  right: 24px;
  font-size: 42px;
  line-height: 1;
  color: rgba(255,255,255,0.7);
  cursor: pointer;
  font-family: sans-serif;
  user-select: none;
  transition: opacity 0.15s;
}
#image-popup .close-btn:hover {
  opacity: 1;
}
/* Clickable images */
img.viewable {
  cursor: zoom-in;
}