:root {
  --bg: #faf7f2;
  --surface: #ffffff;
  --text: #2b2320;
  --muted: #8a7c72;
  --accent: #b8895f;
  --accent-dark: #8f6a48;
  --border: #ece4da;
  --grid-gap: 4px;
  --unit: 110px;
}

* { box-sizing: border-box; }

/* Alcune regole qui sotto impostano `display` sulle stesse classi usate da
   elementi con l'attributo [hidden] (modale, lightbox, banner): senza questa
   regola, quel `display` vince sempre sullo stile di default di [hidden]. */
[hidden] { display: none !important; }

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 12px;
  padding: 12px 16px;
  background: rgba(250, 247, 242, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.topbar h1 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0;
  flex: 1 1 auto;
  min-width: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.controls {
  display: flex;
  gap: 8px;
  align-items: center;
  flex: 1 1 100%;
}

.controls > * {
  flex: 1 1 0;
  min-width: 0;
}

#authorFilter {
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: 20px;
  padding: 7px 12px;
  font-size: 0.85rem;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: 20px;
  padding: 7px 12px;
  font-size: 0.85rem;
  color: var(--text);
  white-space: nowrap;
  cursor: pointer;
}

.icon-btn:active { background: var(--border); }

.new-photos-banner {
  position: sticky;
  top: 62px;
  z-index: 19;
  display: flex;
  justify-content: center;
  padding: 8px 0;
}

.new-photos-banner button {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 20px;
  padding: 8px 16px;
  font-size: 0.85rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  cursor: pointer;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(var(--unit), 1fr));
  grid-auto-rows: var(--unit);
  grid-auto-flow: dense;
  gap: var(--grid-gap);
  padding: var(--grid-gap);
}

.tile {
  position: relative;
  overflow: hidden;
  cursor: pointer;
  background: var(--border);
}

.tile.featured {
  grid-column: span 2;
  grid-row: span 2;
}

.tile img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.25s ease;
}

.tile:active img { transform: scale(1.03); }

.tile-caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 18px 8px 6px;
  background: linear-gradient(to top, rgba(0,0,0,0.55), transparent);
  color: #fff;
  font-size: 0.72rem;
  opacity: 0;
  transition: opacity 0.2s ease;
  pointer-events: none;
}

.tile:hover .tile-caption,
.tile:active .tile-caption {
  opacity: 1;
}

.empty-state {
  text-align: center;
  color: var(--muted);
  margin-top: 64px;
  font-size: 0.95rem;
}

.fab {
  position: fixed;
  right: 20px;
  bottom: 24px;
  width: 58px;
  height: 58px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 14px rgba(0,0,0,0.25);
  cursor: pointer;
  z-index: 25;
}

.fab:active { background: var(--accent-dark); }

.upload-progress {
  position: fixed;
  left: 16px;
  right: 16px;
  bottom: 96px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 14px;
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
  z-index: 25;
  font-size: 0.8rem;
  color: var(--muted);
}

.upload-progress-bar {
  height: 6px;
  border-radius: 3px;
  background: var(--border);
  overflow: hidden;
  margin-bottom: 6px;
}

#uploadProgressFill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.15s ease;
}

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(20, 15, 10, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 50;
  padding: 20px;
}

.modal {
  background: var(--surface);
  border-radius: 16px;
  padding: 28px 24px;
  max-width: 360px;
  width: 100%;
  text-align: center;
  box-shadow: 0 10px 40px rgba(0,0,0,0.25);
}

.modal h2 { margin: 0 0 8px; }
.modal p { color: var(--muted); font-size: 0.9rem; margin: 0 0 18px; }

.modal form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.modal input {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
  font-size: 1rem;
}

.modal button {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 12px;
  font-size: 1rem;
  cursor: pointer;
}

.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.94);
  z-index: 60;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lightbox img {
  max-width: 92vw;
  max-height: 82vh;
  object-fit: contain;
}

.lightbox-close {
  position: absolute;
  top: 14px;
  right: 16px;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.6rem;
  cursor: pointer;
  z-index: 61;
}

.lightbox-nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255,255,255,0.1);
  border: none;
  color: #fff;
  font-size: 2rem;
  width: 44px;
  height: 64px;
  cursor: pointer;
  border-radius: 6px;
}

.lightbox-prev { left: 10px; }
.lightbox-next { right: 10px; }

.lightbox-caption {
  position: absolute;
  bottom: 16px;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: #fff;
  font-size: 0.85rem;
}

.lightbox-caption a {
  color: #fff;
  display: flex;
}

@media (min-width: 480px) {
  .controls { flex: 0 0 auto; }
  .controls > * { flex: 0 0 auto; }
  #authorFilter { max-width: 220px; }
}

@media (min-width: 700px) {
  :root { --unit: 160px; }
}