/* ===========================
   Audible Explorer - Dark Theme
   =========================== */

:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: rgba(17, 24, 39, 0.85);
  --bg-card-hover: rgba(24, 34, 56, 0.95);
  --bg-controls: rgba(10, 14, 26, 0.95);
  --border-color: rgba(255, 255, 255, 0.06);
  --border-card: rgba(255, 255, 255, 0.08);
  --text-primary: #f0f2f5;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --accent-orange: #f59e0b;
  --accent-orange-dim: rgba(245, 158, 11, 0.15);
  --accent-teal: #06b6d4;
  --accent-teal-dim: rgba(6, 182, 212, 0.15);
  --accent-purple: #a78bfa;
  --accent-purple-dim: rgba(167, 139, 250, 0.15);
  --upcoming-badge: #ef4444;
  --upcoming-overlay: rgba(0, 0, 0, 0.45);
  --pill-bg: rgba(255, 255, 255, 0.06);
  --pill-active: rgba(245, 158, 11, 0.2);
  --pill-active-border: rgba(245, 158, 11, 0.5);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 20px rgba(245, 158, 11, 0.1);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-pill: 100px;
  --transition: 0.2s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', 'Noto Sans JP', -apple-system, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
}

/* ======= Header ======= */
.header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 24px;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(20px);
}

.header-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  font-size: 32px;
  filter: drop-shadow(0 0 8px rgba(245, 158, 11, 0.3));
}

.logo-title {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, #f59e0b, #fbbf24);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-subtitle {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0.5px;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 24px;
}

.stats {
  text-align: center;
}

.stats-count {
  display: block;
  font-size: 20px;
  font-weight: 700;
  color: var(--accent-orange);
}

.stats-count-small {
  font-size: 12px;
  font-weight: 500;
}

.stats-label {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.stats-date {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

/* ======= Controls ======= */
.controls {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px 24px 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: sticky;
  top: 73px;
  z-index: 90;
  background: var(--bg-primary);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
}

/* Search */
.search-bar {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 16px;
  width: 20px;
  height: 20px;
  color: var(--text-muted);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 14px 44px 14px 48px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 15px;
  font-family: inherit;
  outline: none;
  transition: border var(--transition), box-shadow var(--transition);
}

.search-input::placeholder {
  color: var(--text-muted);
}

.search-input:focus {
  border-color: var(--accent-orange);
  box-shadow: 0 0 0 3px var(--accent-orange-dim);
}

.search-clear {
  position: absolute;
  right: 12px;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 16px;
  padding: 4px 8px;
  border-radius: 4px;
  display: none;
}

.search-clear.visible {
  display: block;
}

.search-clear:hover {
  color: var(--text-primary);
  background: var(--pill-bg);
}

/* Filter Row */
.filter-row, .sort-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.filter-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  white-space: nowrap;
}

.pill-group {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.pill {
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-color);
  background: var(--pill-bg);
  color: var(--text-secondary);
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.pill:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  border-color: rgba(255, 255, 255, 0.15);
}

.pill.active {
  background: var(--pill-active);
  color: var(--accent-orange);
  border-color: var(--pill-active-border);
  font-weight: 500;
}

/* Toggle */
.toggle-label {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  user-select: none;
}

.toggle-input {
  display: none;
}

.toggle-switch {
  width: 40px;
  height: 22px;
  background: var(--pill-bg);
  border-radius: 11px;
  position: relative;
  transition: background var(--transition);
  border: 1px solid var(--border-color);
}

.toggle-switch::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  background: var(--text-muted);
  border-radius: 50%;
  transition: transform var(--transition), background var(--transition);
}

.toggle-input:checked + .toggle-switch {
  background: var(--accent-orange-dim);
  border-color: var(--pill-active-border);
}

.toggle-input:checked + .toggle-switch::after {
  transform: translateX(18px);
  background: var(--accent-orange);
}

.toggle-text {
  font-size: 13px;
  color: var(--text-secondary);
}

/* ======= Main Content ======= */
.main-content {
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px;
  min-height: 60vh;
}

/* Book Grid */
.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

/* Book Card */
.book-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  display: block;
  position: relative;
}

.book-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
  border-color: rgba(245, 158, 11, 0.2);
}

.book-card.upcoming {
  opacity: 0.75;
}

.book-card.upcoming:hover {
  opacity: 0.9;
}

/* Upcoming Badge */
.upcoming-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--upcoming-badge);
  color: white;
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  z-index: 5;
  letter-spacing: 0.5px;
  box-shadow: 0 2px 8px rgba(239, 68, 68, 0.4);
}

.book-cover-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  background: var(--bg-secondary);
}

.book-cover {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.book-card:hover .book-cover {
  transform: scale(1.05);
}

.upcoming .book-cover-wrap::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--upcoming-overlay);
  pointer-events: none;
}

.book-info {
  padding: 14px 16px 16px;
}

.book-title {
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 6px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-author {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.book-narrator {
  font-size: 11px;
  color: var(--text-muted);
  margin-bottom: 10px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.book-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.book-rating {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-orange);
}

.book-rating .star {
  font-size: 14px;
}

.book-reviews {
  font-size: 11px;
  color: var(--text-muted);
}

.book-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.tag {
  font-size: 10px;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  font-weight: 500;
  letter-spacing: 0.3px;
}

.tag-series {
  background: var(--accent-teal-dim);
  color: var(--accent-teal);
  border: 1px solid rgba(6, 182, 212, 0.2);
}

.tag-runtime {
  background: var(--accent-purple-dim);
  color: var(--accent-purple);
  border: 1px solid rgba(167, 139, 250, 0.2);
}

.tag-category {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
}

.tag-date {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
}

.tag-upcoming-date {
  background: rgba(239, 68, 68, 0.1);
  color: #fca5a5;
  border: 1px solid rgba(239, 68, 68, 0.2);
}

/* ======= Series View ======= */
.series-view {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.series-group {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.series-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.series-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--accent-teal);
}

.series-count {
  font-size: 12px;
  color: var(--text-muted);
  background: var(--pill-bg);
  padding: 2px 10px;
  border-radius: var(--radius-pill);
}

.series-books {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 16px;
}

/* ======= Loading / Error / No Results ======= */
.loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 80px 20px;
  color: var(--text-muted);
  gap: 16px;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-color);
  border-top-color: var(--accent-orange);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.error-message, .no-results {
  text-align: center;
  padding: 80px 20px;
  color: var(--text-muted);
  font-size: 16px;
}

.error-detail {
  margin-top: 8px;
  font-size: 13px;
}

.error-detail code {
  background: var(--pill-bg);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: 'Consolas', monospace;
  color: var(--accent-orange);
}

/* ======= Footer ======= */
.footer {
  text-align: center;
  padding: 32px 20px;
  color: var(--text-muted);
  font-size: 12px;
  border-top: 1px solid var(--border-color);
  margin-top: 40px;
}

/* ======= Responsive ======= */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    align-items: flex-start;
  }

  .header-right {
    width: 100%;
    justify-content: space-between;
  }

  .controls {
    top: auto;
    position: relative;
  }

  .filter-row {
    flex-direction: column;
    align-items: flex-start;
  }

  .book-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 12px;
  }

  .book-info {
    padding: 10px 12px 12px;
  }

  .book-title {
    font-size: 13px;
  }
}

@media (max-width: 480px) {
  .book-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

  .pill {
    font-size: 12px;
    padding: 5px 10px;
  }
}