/* ═══════════════════════════════════════════════════════════════
   TF Study Shelf — User-Facing Layout
   ═══════════════════════════════════════════════════════════════ */

/* ─── Top Navigation ──────────────────────────────────────── */
.user-topbar {
  height: var(--topbar-height);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-lg);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(250, 250, 250, 0.85);
}

[data-theme="dark"] .user-topbar {
  background: rgba(33, 33, 33, 0.85);
}

.user-topbar__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  cursor: pointer;
}

.user-topbar__logo-mark {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font: 700 12px/1 var(--font-primary);
  color: #fff;
}

.user-topbar__logo-text {
  font: 600 16px/24px var(--font-primary);
  color: var(--text-primary);
}

.user-topbar__center {
  flex: 1;
  max-width: 480px;
  margin: 0 var(--space-xl);
}

.user-topbar__right {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.user-topbar__link {
  font: 500 14px/20px var(--font-primary);
  color: var(--text-secondary);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.user-topbar__link:hover {
  color: var(--text-primary);
  background: var(--bg-elevated);
}

.user-topbar__link.active {
  color: var(--accent);
}

/* ─── Main Content ────────────────────────────────────────── */
.user-main {
  min-height: calc(100vh - var(--topbar-height));
}

.user-content {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
}

/* ─── Hero Section ────────────────────────────────────────── */
.hero {
  background: var(--gradient-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-3xl) var(--space-2xl);
  color: #FAFAFA;
  margin-bottom: var(--space-xl);
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(ellipse, rgba(255,119,89,0.2), transparent 70%);
  pointer-events: none;
}

.hero__title {
  font: 700 36px/44px var(--font-primary);
  margin-bottom: var(--space-sm);
  position: relative;
  z-index: 1;
}

.hero__subtitle {
  font: 400 16px/24px var(--font-primary);
  opacity: 0.8;
  margin-bottom: var(--space-lg);
  max-width: 480px;
  position: relative;
  z-index: 1;
}

.hero__actions {
  display: flex;
  gap: var(--space-md);
  position: relative;
  z-index: 1;
}

/* ─── Section Headers ─────────────────────────────────────── */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.section-title {
  font: 600 20px/28px var(--font-primary);
  color: var(--text-primary);
}

.section-link {
  font: 500 14px/20px var(--font-primary);
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 4px;
}

.section-link:hover { opacity: 0.8; }

/* ─── Category Rail ───────────────────────────────────────── */
.category-rail {
  display: flex;
  gap: var(--space-sm);
  overflow-x: auto;
  padding-bottom: var(--space-sm);
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.category-rail::-webkit-scrollbar { display: none; }

.category-rail__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-md);
  min-width: 90px;
  border-radius: var(--radius-md);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
}

.category-rail__item:hover {
  border-color: var(--accent);
  background: var(--color-accent-subtle);
}

.category-rail__icon {
  font-size: 24px;
}

.category-rail__name {
  font: 500 12px/16px var(--font-primary);
  color: var(--text-primary);
}

/* ─── Books Grid ──────────────────────────────────────────── */
.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--space-md);
}

.books-grid--list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

/* ─── Horizontal Scroll Section ───────────────────────────── */
.horizontal-scroll {
  display: flex;
  gap: var(--space-md);
  overflow-x: auto;
  padding-bottom: var(--space-sm);
  scrollbar-width: none;
  scroll-snap-type: x mandatory;
}

.horizontal-scroll::-webkit-scrollbar { display: none; }

.horizontal-scroll > * {
  scroll-snap-align: start;
  flex-shrink: 0;
}

/* ─── Continue Reading Card ───────────────────────────────── */
.continue-card {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  width: 300px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.continue-card:hover {
  box-shadow: var(--shadow-2);
  transform: translateY(-2px);
}

.continue-card__cover {
  width: 60px;
  height: 80px;
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  overflow: hidden;
  flex-shrink: 0;
}

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

.continue-card__info { flex: 1; display: flex; flex-direction: column; justify-content: center; gap: 4px; }
.continue-card__title { font: 600 14px/20px var(--font-primary); color: var(--text-primary); }
.continue-card__author { font: 400 12px/16px var(--font-primary); color: var(--text-secondary); }
.continue-card__progress { margin-top: var(--space-xs); }
.continue-card__page { font: 400 12px/16px var(--font-mono); color: var(--text-tertiary); margin-top: 2px; }

/* ─── Book Detail ─────────────────────────────────────────── */
.book-detail {
  max-width: 900px;
  margin: 0 auto;
}

.book-detail__header {
  display: flex;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.book-detail__cover {
  width: 240px;
  aspect-ratio: 3/4;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-3);
  flex-shrink: 0;
}

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

.book-detail__info {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.book-detail__title { font: 700 28px/36px var(--font-primary); }
.book-detail__author { font: 400 16px/24px var(--font-primary); color: var(--text-secondary); }

.book-detail__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  font: 400 14px/20px var(--font-primary);
  color: var(--text-secondary);
}

.book-detail__meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

.book-detail__actions {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  flex-wrap: wrap;
}

.book-detail__description {
  font: 400 16px/26px var(--font-primary);
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
}

/* ─── Chapter List ────────────────────────────────────────── */
.chapter-list {
  display: flex;
  flex-direction: column;
}

.chapter-item {
  padding: var(--space-md);
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.chapter-item:hover { background: var(--bg-elevated); }
.chapter-item:last-child { border-bottom: none; }

.chapter-item__number {
  font: 500 12px/16px var(--font-mono);
  color: var(--accent);
  margin-bottom: 4px;
}

.chapter-item__title {
  font: 500 16px/24px var(--font-primary);
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

.chapter-item__meta {
  display: flex;
  gap: var(--space-md);
  font: 400 12px/16px var(--font-primary);
  color: var(--text-tertiary);
}

/* ─── Footer ──────────────────────────────────────────────── */
.user-footer {
  background: var(--color-primary-dark);
  color: rgba(250, 250, 250, 0.7);
  padding: var(--space-2xl) var(--space-lg);
  margin-top: var(--space-3xl);
}

.footer-content {
  max-width: var(--content-max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
}

.footer-brand__name {
  font: 600 18px/24px var(--font-primary);
  color: #FAFAFA;
  margin-bottom: var(--space-sm);
}

.footer-brand__tagline {
  font: 400 14px/22px var(--font-primary);
  max-width: 280px;
}

.footer-links__title {
  font: 600 13px/18px var(--font-primary);
  color: #FAFAFA;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
}

.footer-links a {
  display: block;
  padding: 4px 0;
  font: 400 14px/22px var(--font-primary);
  color: rgba(250, 250, 250, 0.6);
  transition: color var(--transition-fast);
}

.footer-links a:hover { color: var(--accent); }

.footer-bottom {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding-top: var(--space-lg);
  margin-top: var(--space-xl);
  border-top: 1px solid rgba(250, 250, 250, 0.1);
  display: flex;
  justify-content: space-between;
  font: 400 12px/16px var(--font-primary);
  color: rgba(250, 250, 250, 0.4);
}

/* ─── Responsive User Layout ─────────────────────────────── */
@media (max-width: 767px) {
  .user-topbar__center { display: none; }

  .hero {
    padding: var(--space-xl) var(--space-lg);
  }

  .hero__title { font-size: 24px; line-height: 32px; }

  .book-detail__header {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .book-detail__cover { width: 180px; }
  .book-detail__actions { justify-content: center; }
  .book-detail__meta { justify-content: center; }

  .books-grid { grid-template-columns: repeat(2, 1fr); }

  .footer-content { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: var(--space-sm); }
}

@media (min-width: 768px) and (max-width: 1023px) {
  .books-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-content { grid-template-columns: repeat(2, 1fr); }
}