:root {
  --bg: #ffffff;
  --fg: #111111;
  --card-bg: #f3f3f3;
  --primary: #111111;
  --overlay: #000000;
  --thumb-size: 220px;
  --gap: 12px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  overflow-x: hidden;
}

#app { padding: 20px; min-height: 100vh; }
.view[hidden] { display: none; }

.back-button {
  background: none; border: none; font-size: 15px; color: var(--fg);
  cursor: pointer; padding: 6px 0 16px; display: block;
}
.back-button[hidden] { display: none; }

.gallery-title { margin: 0 0 16px; font-size: 22px; }

/* --- Vignettes de sous-galeries --- */

.galleries-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 18px;
  margin-bottom: 24px;
}
.galleries-grid:empty { display: none; margin: 0; }

.gallery-card {
  cursor: pointer;
  border-radius: 10px;
  overflow: hidden;
  background: var(--card-bg);
  position: relative;
  aspect-ratio: 4 / 3;
  transition: transform 0.2s ease;
}
.gallery-card:hover { transform: translateY(-3px); }
.gallery-card img { width: 100%; height: 100%; object-fit: cover; display: block; position: relative; z-index: 1; }
.gallery-card .placeholder-icon {
  width: 100%; height: 100%; display: flex; align-items: center; justify-content: center;
  font-size: 40px; opacity: 0.4; position: relative; z-index: 1;
}
.gallery-card-label {
  position: absolute; left: 0; right: 0; bottom: 0; z-index: 1;
  padding: 12px 14px;
  background: linear-gradient(transparent, rgba(0, 0, 0, 0.65));
  color: #fff; font-weight: 600; font-size: 15px;
}

/* --- Grille de photos --- */

.photos-grid {
  display: grid;
  gap: var(--gap);
  grid-template-columns: repeat(auto-fill, minmax(var(--thumb-size), 1fr));
}
.photos-grid[data-columns="2"] { grid-template-columns: repeat(2, 1fr); }
.photos-grid[data-columns="3"] { grid-template-columns: repeat(3, 1fr); }
.photos-grid[data-columns="4"] { grid-template-columns: repeat(4, 1fr); }
.photos-grid[data-columns="5"] { grid-template-columns: repeat(5, 1fr); }

.photo-thumb {
  cursor: pointer;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  border-radius: 6px;
  background: var(--card-bg);
  position: relative;
}
.photo-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; position: relative; z-index: 1; }

/* --- Skeleton/shimmer pendant le chargement --- */
.photo-thumb::before,
.gallery-card::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(100deg, var(--card-bg) 28%, rgba(255, 255, 255, 0.35) 50%, var(--card-bg) 72%);
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.4s ease-in-out infinite;
  opacity: 1;
  transition: opacity 0.35s ease;
}
.photo-thumb.img-loaded::before,
.gallery-card.img-loaded::before {
  opacity: 0;
}
@keyframes skeleton-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* Effets au survol des vignettes : combinables, pilotes par data-* sur la grille */

/* Zoom (intensite via --hover-zoom-scale) */
.photos-grid[data-zoom="1"] .photo-thumb img { transition: transform 0.25s ease; }
.photos-grid[data-zoom="1"] .photo-thumb:hover img { transform: scale(var(--hover-zoom-scale, 1.08)); }

/* Assombrissement degrade (vertical et/ou horizontal, cumulables) via un calque dedie */
.thumb-darken {
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  border-radius: 6px;
  background: var(--thumb-darken-bg, none);
  opacity: 0;
  transition: opacity 0.3s ease;
}
.photos-grid[data-darken-v="1"] .photo-thumb:hover .thumb-darken,
.photos-grid[data-darken-h="1"] .photo-thumb:hover .thumb-darken {
  opacity: 1;
}

/* Bordure (intensite = epaisseur via --hover-border-width) */
.photos-grid[data-border="1"] .photo-thumb {
  border: var(--hover-border-width, 3px) solid transparent;
  transition: border-color 0.2s ease;
}
.photos-grid[data-border="1"] .photo-thumb:hover { border-color: var(--primary); }

/* Trait sous la vignette (intensite = epaisseur via --hover-underline-height) */
.thumb-underline {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 0;
  z-index: 3;
  background: var(--primary);
  transition: height 0.2s ease;
}
.photos-grid[data-underline="1"] .photo-thumb:hover .thumb-underline {
  height: var(--hover-underline-height, 3px);
}

.scroll-sentinel { height: 1px; }

/* --- Apparition des vignettes (fade in + montee) --- */
/* Premiere apparition : animation complete. Reapparition (deja vue) : version courte et discrete. */

@keyframes reveal-rise {
  from { opacity: 0; transform: translateY(26px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes reveal-rise-quick {
  from { opacity: 0.2; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.photo-thumb, .gallery-card { opacity: 0; }

.photo-thumb.thumb-visible,
.gallery-card.thumb-visible {
  animation: reveal-rise 0.55s cubic-bezier(0.22, 0.61, 0.36, 1) forwards;
  animation-delay: var(--reveal-delay, 0ms);
}

.photo-thumb.thumb-visible-quick,
.gallery-card.thumb-visible-quick {
  animation: reveal-rise-quick 0.2s ease-out forwards;
}

@media (prefers-reduced-motion: reduce) {
  .photo-thumb, .gallery-card { opacity: 1; animation: none !important; }
  .photo-thumb.thumb-visible, .gallery-card.thumb-visible,
  .photo-thumb.thumb-visible-quick, .gallery-card.thumb-visible-quick { animation: none !important; }
}

/* --- Visionneuse immersive --- */

.viewer {
  position: fixed; inset: 0; z-index: 1000; display: flex; align-items: center; justify-content: center;
  opacity: 0;
  transition: opacity 0.22s ease;
}
.viewer[hidden] { display: none; }
.viewer.viewer-visible { opacity: 1; }
.viewer-backdrop { position: absolute; inset: 0; background: var(--overlay); }

.viewer-image {
  position: relative; max-width: 90vw; max-height: 90vh; object-fit: contain; z-index: 1; opacity: 0;
  perspective: 1000px;
}
.viewer-image.visible { opacity: 1; }

.viewer-image.transition-fade { transition: opacity 0.25s ease; }

.viewer-image.transition-slide { transition: opacity 0.2s ease, transform 0.25s ease; transform: translateX(40px); }
.viewer-image.transition-slide.visible { transform: translateX(0); }

.viewer-image.transition-slide-vertical { transition: opacity 0.2s ease, transform 0.25s ease; transform: translateY(40px); }
.viewer-image.transition-slide-vertical.visible { transform: translateY(0); }

.viewer-image.transition-zoom { transition: opacity 0.2s ease, transform 0.25s ease; transform: scale(0.88); }
.viewer-image.transition-zoom.visible { transform: scale(1); }

.viewer-image.transition-flip { transition: opacity 0.2s ease, transform 0.3s ease; transform: rotateY(18deg); }
.viewer-image.transition-flip.visible { transform: rotateY(0deg); }

.viewer-close {
  position: absolute; top: 20px; right: 24px; z-index: 2; background: none; border: none;
  color: #fff; font-size: 34px; line-height: 1; cursor: pointer; opacity: 0.85;
}
.viewer-arrow {
  position: absolute; top: 50%; transform: translateY(-50%); z-index: 2; background: none; border: none;
  color: #fff; font-size: 60px; line-height: 1; cursor: pointer; padding: 10px 18px; opacity: 0.85;
  transition: opacity 0.2s ease;
}
.viewer-arrow-left { left: 6px; }
.viewer-arrow-right { right: 6px; }
.viewer[data-arrows="hover"] .viewer-arrow { opacity: 0; }
.viewer[data-arrows="hover"]:hover .viewer-arrow { opacity: 0.85; }

/* Sur ecran tactile (pas de :hover fiable), les fleches restent visibles */
@media (hover: none) {
  .viewer[data-arrows="hover"] .viewer-arrow { opacity: 0.85; }
}

.viewer-image.dragging { transition: none !important; }

/* Empeche tout scroll/geste par defaut sur la visionneuse (y compris la zone
   noire du fond) : evite que la grille de miniatures ne defile derriere. */
.viewer { touch-action: none; }

/* Bloque le scroll de la page pendant que la visionneuse est ouverte.
   Combine avec un verrouillage position:fixed en JS (compatible iOS Safari). */
body.viewer-open {
  overflow: hidden;
}

/* --- Indicateur de chargement en mode zoom --- */
.viewer-spinner {
  position: absolute;
  z-index: 1;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 3px solid rgba(255, 255, 255, 0.25);
  border-top-color: #fff;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
}
.viewer.viewer-loading .viewer-spinner {
  opacity: 1;
  animation: viewer-spin 0.8s linear infinite;
}
@keyframes viewer-spin {
  to { transform: rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .viewer, .viewer-image, .gallery-card { transition-duration: 0.001ms !important; }
  .viewer-spinner.viewer-loading, .viewer.viewer-loading .viewer-spinner { animation: none !important; }
}

@media (max-width: 640px) {
  .viewer-arrow { font-size: 40px; padding: 8px 10px; }
  .viewer-close { font-size: 28px; top: 12px; right: 14px; }
}