/* ── Hero ───────────────────────────────────────────────── */
.hero {
  max-width: 800px;
  margin: 100px auto 80px;
  padding: 0 40px;
  text-align: center;
}
.hero h1 {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -1.5px;
  margin-bottom: 20px;
}
.hero-sub {
  font-size: 18px;
  color: var(--text-dim);
  max-width: 520px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

/* ── 内容库 ──────────────────────────────────────────────── */
.library-section {
  max-width: 1200px;
  margin: 0 auto 80px;
  padding: 0 40px;
}
.section-header { margin-bottom: 32px; }
.section-header h2 { font-size: 28px; font-weight: 700; margin-bottom: 6px; }
.section-sub { color: var(--text-dim); font-size: 15px; }

.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}

/* 卡片 */
.library-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.2s;
}
.library-card:hover { border-color: var(--accent); transform: translateY(-2px); }

.card-thumb {
  width: 100%;
  aspect-ratio: 16/9;
  object-fit: cover;
  background: var(--surface2);
}
.card-thumb-placeholder {
  width: 100%;
  aspect-ratio: 16/9;
  background: var(--surface2);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-dim);
  font-size: 32px;
}

.card-body { padding: 16px; }
.card-title { font-size: 15px; font-weight: 600; margin-bottom: 4px; }
.card-meta { font-size: 13px; color: var(--text-dim); margin-bottom: 10px; }

.card-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tag {
  padding: 3px 10px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 12px;
  color: var(--text-dim);
}

/* Skeleton */
.skeleton-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  aspect-ratio: 16/11;
  animation: shimmer 1.4s ease-in-out infinite;
}
@keyframes shimmer {
  0%, 100% { opacity: 0.4; }
  50%       { opacity: 0.7; }
}

/* ── CTA ──────────────────────────────────────────────────── */
.cta-section {
  text-align: center;
  padding: 80px 40px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-bottom: 0;
}
.cta-section h2 { font-size: 32px; font-weight: 700; margin-bottom: 12px; }
.cta-section p { color: var(--text-dim); margin-bottom: 28px; font-size: 16px; }