/* ============================================================
   BOOKS PAGE — filter bar, catalog grid, full book cards
   ============================================================ */

/* --- Filter bar --- */
.filter-bar {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
}

.filter-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-ui);
  font-size: 12px;
  letter-spacing: 0.08em;
  padding: 7px 16px;
  border: var(--border-subtle);
  border-radius: var(--radius-sm);
  background: none;
  color: var(--text-tertiary);
  cursor: pointer;
  transition: all var(--transition);
}

.filter-btn:hover {
  border-color: var(--gold-dim);
  color: var(--gold);
}

.filter-btn.active,
.filter-btn[aria-pressed="true"] {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink-0);
}

/* --- Books grid --- */
.books-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-lg);
}

@media (max-width: 900px) {
  .books-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 560px) {
  .books-grid { grid-template-columns: 1fr; }
}

/* --- Full book card --- */
.book-full-card {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: var(--space-lg);
  align-items: start;
  padding: var(--space-lg);
}

.book-full-card__cover {
  width: 140px;
  aspect-ratio: 2 / 3;
  background: var(--ink-0);
  border: var(--border-subtle);
  border-radius: var(--radius-sm);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.book-full-card__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.book-full-card__cover-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  color: var(--gold-dim);
  font-size: 36px;
}

.book-full-card__title {
  font-size: 1.15rem;
  color: var(--text-primary);
  line-height: 1.25;
  margin-bottom: 2px;
}

.book-full-card__author {
  font-family: var(--font-ui);
  font-size: 12px;
  color: var(--gold-dim);
  letter-spacing: 0.06em;
  margin-bottom: var(--space-md);
}

.book-full-card__description {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}

/* Format tags */
.format-tags {
  display: flex;
  gap: 5px;
  flex-wrap: wrap;
  margin-bottom: var(--space-md);
}

.format-tag {
  font-family: var(--font-ui);
  font-size: 10px;
  letter-spacing: 0.08em;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  border: var(--border-subtle);
  color: var(--text-tertiary);
}

/* Retailer section */
.retailer-label {
  font-family: var(--font-ui);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold-dim);
  margin-bottom: var(--space-sm);
}

.retailer-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.retailer-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-ui);
  font-size: 11px;
  padding: 5px 12px;
  border: var(--border-gold);
  border-radius: var(--radius-sm);
  color: var(--gold);
  text-decoration: none;
  transition: all var(--transition);
  white-space: nowrap;
}

.retailer-btn:hover {
  background: var(--gold);
  color: var(--ink-0);
  border-color: var(--gold);
}

/* --- Skeleton --- */
@keyframes shimmer {
  0%   { opacity: 0.4; }
  50%  { opacity: 0.7; }
  100% { opacity: 0.4; }
}

.book-full-skeleton {
  background: var(--ink-2);
  border: var(--border-subtle);
  border-radius: var(--radius-lg);
  min-height: 220px;
  animation: shimmer 1.6s ease-in-out infinite;
}

/* --- Empty state --- */
.empty-state {
  text-align: center;
  padding: var(--space-2xl);
  color: var(--text-muted);
  font-family: var(--font-ui);
  font-size: 14px;
  grid-column: 1 / -1;
}

/* --- Hidden card (filtered out) --- */
.book-full-card[hidden] {
  display: none;
}

/* --- Responsive: stack cover above content on small screens --- */
@media (max-width: 560px) {
  .book-full-card {
    grid-template-columns: 1fr;
  }

  .book-full-card__cover {
    width: 120px;
    margin: 0 auto;
  }
}