:root {
  --bg: #0f1115;
  --surface: #181b22;
  --surface-hover: #232732;
  --border: #2a2f3a;
  --text: #e6e8ee;
  --text-dim: #8a8f9c;
  --accent: #7aa2f7;
  --accent-hover: #9ab8ff;
  --danger: #f7768e;
  --danger-hover: #ff8da3;
}
* { box-sizing: border-box; }
html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  padding-bottom: 88px;
}
header {
  padding: 24px 32px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.title-block { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
h1 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.breadcrumb { color: var(--text-dim); font-size: 13px; }
.breadcrumb a { color: var(--accent); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent-hover); text-decoration: underline; }
.meta { color: var(--text-dim); font-size: 12px; }
.actions { margin-left: auto; display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  background: var(--accent);
  color: #0f1115;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 8px;
  border: 0;
  cursor: pointer;
  transition: background 0.12s, transform 0.12s;
}
.btn:hover { background: var(--accent-hover); transform: translateY(-1px); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }
.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--surface-hover); border-color: var(--accent); }
.btn-danger { background: var(--danger); }
.btn-danger:hover { background: var(--danger-hover); }
main { padding: 24px 32px 48px; }
.notice {
  margin: 0 0 20px;
  padding: 12px 16px;
  background: rgba(122, 162, 247, 0.08);
  border: 1px solid rgba(122, 162, 247, 0.25);
  border-radius: 8px;
  font-size: 13px;
  color: var(--text-dim);
}
.notice strong { color: var(--text); }
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  transition: background 0.12s, border-color 0.12s, transform 0.12s, box-shadow 0.12s;
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--text);
  position: relative;
}
.card:hover {
  background: var(--surface-hover);
  border-color: var(--accent);
  transform: translateY(-2px);
}
.card.selected {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent), 0 8px 24px rgba(122, 162, 247, 0.2);
  background: var(--surface-hover);
}
.thumb {
  aspect-ratio: 4 / 3;
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}
.thumb img, .thumb video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.thumb .icon { font-size: 52px; color: var(--text-dim); }
.play-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(180deg, transparent 50%, rgba(0,0,0,0.55) 100%);
  pointer-events: none;
}
.play-icon {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: rgba(255,255,255,0.92);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #000;
  font-size: 22px;
  padding-left: 4px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
}
.check-overlay {
  position: absolute;
  top: 8px;
  left: 8px;
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: rgba(15, 17, 21, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1.5px solid rgba(255,255,255,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 3;
  transition: background 0.12s, border-color 0.12s, transform 0.12s;
  user-select: none;
}
.check-overlay::after {
  content: "";
  width: 14px;
  height: 14px;
  border-radius: 4px;
  border: 1.5px solid rgba(255,255,255,0.55);
  background: transparent;
  transition: background 0.12s, border-color 0.12s;
}
.card.selected .check-overlay { background: var(--accent); border-color: var(--accent); }
.card.selected .check-overlay::after {
  background: var(--accent);
  border-color: #0f1115;
  background-image: linear-gradient(45deg, transparent 50%, transparent 50%);
  position: relative;
}
.card.selected .check-overlay {
  background: var(--accent);
}
.card.selected .check-overlay::after {
  content: "✓";
  border: none;
  background: transparent;
  color: #0f1115;
  font-size: 18px;
  font-weight: bold;
  display: flex;
  align-items: center;
  justify-content: center;
  width: auto;
  height: auto;
}
.download-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: rgba(15, 17, 21, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  text-decoration: none;
  font-size: 14px;
  border: 1.5px solid rgba(255,255,255,0.4);
  opacity: 0;
  transition: opacity 0.15s, background 0.12s, transform 0.12s;
  z-index: 3;
}
.card:hover .download-btn { opacity: 1; }
.download-btn:hover { background: var(--accent); color: #0f1115; transform: scale(1.08); }
@media (hover: none) {
  .download-btn { opacity: 1; }
}
.info {
  padding: 10px 14px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}
.name {
  font-size: 13px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.sub {
  font-size: 11px;
  color: var(--text-dim);
  display: flex;
  justify-content: space-between;
  gap: 8px;
}
.folder .thumb { background: linear-gradient(135deg, #2a3447 0%, #1a2030 100%); }
.folder .thumb .icon { color: var(--accent); }

.selection-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 14px 32px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  box-shadow: 0 -10px 30px rgba(0,0,0,0.4);
  transform: translateY(100%);
  transition: transform 0.2s ease;
  z-index: 10;
}
.selection-bar.visible { transform: translateY(0); }
.selection-count {
  font-weight: 600;
  font-size: 14px;
}
.selection-actions { margin-left: auto; display: flex; gap: 8px; flex-wrap: wrap; }

.toast {
  position: fixed;
  bottom: 100px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 18px;
  font-size: 13px;
  opacity: 0;
  transition: opacity 0.2s, transform 0.2s;
  z-index: 20;
  pointer-events: none;
  max-width: 90vw;
  text-align: center;
}
.toast.visible { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast.error { border-color: var(--danger); color: var(--danger); }
.toast.success { border-color: var(--accent); color: var(--accent); }

@media (max-width: 600px) {
  header { padding: 16px 16px 14px; }
  main { padding: 16px; }
  .actions { width: 100%; margin-left: 0; }
  .actions .btn { flex: 1; justify-content: center; }
  .grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
  .download-btn { opacity: 1; }
  .selection-bar { padding: 12px 16px; }
  .selection-actions { width: 100%; margin-left: 0; }
  .selection-actions .btn { flex: 1; justify-content: center; }
}