.syllabus-teaser {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 18px;
}

.syllabus-intro-card,
.syllabus-card,
.lesson-panel,
.lesson-side-card,
.chapter-hero,
.chapter-nav-card,
.source-card {
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--surface);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
}

.syllabus-intro-card {
  padding: 24px;
}

.syllabus-intro-card h3,
.chapter-hero h1,
.lesson-panel h2,
.chapter-nav-card h3,
.source-card h3 {
  margin: 0 0 10px;
  font-family: "Fraunces", serif;
}

.syllabus-intro-card p,
.syllabus-card p,
.chapter-hero p,
.lesson-panel p,
.lesson-side-card p,
.source-card p,
.fact-list li,
.mixup-list li,
.chapter-nav-card p {
  color: var(--muted);
  line-height: 1.7;
}

.source-pills,
.chapter-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.source-pills {
  margin-top: 18px;
}

.source-pills a,
.chapter-meta span {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0 14px;
  border-radius: 999px;
  color: var(--primary);
  font-size: 0.84rem;
  font-weight: 800;
  text-decoration: none;
  background: rgba(15, 95, 85, 0.08);
  border: 1px solid rgba(15, 95, 85, 0.12);
}

.syllabus-card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.syllabus-card {
  display: grid;
  gap: 10px;
  padding: 22px;
  color: inherit;
  text-decoration: none;
  transition: transform 170ms ease, border-color 170ms ease, background 170ms ease;
}

.syllabus-card:hover,
.chapter-nav-card:hover {
  transform: translateY(-3px);
  border-color: rgba(15, 95, 85, 0.3);
  background: rgba(255, 255, 255, 0.72);
}

.syllabus-number {
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.syllabus-card strong {
  font-size: 1.08rem;
}

.materials-shell {
  width: min(1240px, calc(100% - 32px));
  margin: 0 auto;
  padding-bottom: 56px;
}

.materials-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
  padding: 22px 0 10px;
}

.materials-nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.materials-nav a {
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 800;
  text-decoration: none;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.chapter-hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 18px;
  padding: 28px;
  margin-top: 18px;
}

.chapter-hero h1 {
  margin-top: 8px;
  font-size: clamp(2.35rem, 5vw, 4.3rem);
  line-height: 0.96;
}

.chapter-hero .hero-note {
  max-width: 60ch;
  margin-top: 14px;
}

.chapter-art {
  position: relative;
  overflow: hidden;
  min-height: 320px;
  border-radius: 24px;
  background:
    radial-gradient(circle at top right, rgba(243, 215, 191, 0.35), transparent 35%),
    linear-gradient(160deg, rgba(16, 53, 96, 0.95), rgba(10, 67, 61, 0.95));
}

.chapter-art svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.art-caption {
  position: absolute;
  right: 18px;
  bottom: 18px;
  max-width: 220px;
  padding: 14px;
  border-radius: 18px;
  color: #fdf8f2;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.16);
}

.lesson-layout {
  display: grid;
  grid-template-columns: 0.34fr 1fr;
  gap: 18px;
  margin-top: 18px;
}

.lesson-sidebar {
  display: grid;
  gap: 14px;
  align-content: start;
}

.lesson-side-card,
.source-card {
  padding: 18px;
}

.syllabus-rail {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.syllabus-rail li a {
  display: grid;
  gap: 4px;
  padding: 14px;
  border-radius: 18px;
  color: inherit;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.58);
  border: 1px solid var(--line);
}

.syllabus-rail li a.active {
  border-color: rgba(15, 95, 85, 0.45);
  background: rgba(15, 95, 85, 0.08);
}

.rail-number {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.lesson-main {
  display: grid;
  gap: 18px;
}

.lesson-panel {
  padding: 22px;
}

.lesson-panel h2 {
  font-size: 1.55rem;
}

.fact-grid,
.graphic-grid,
.source-grid {
  display: grid;
  gap: 14px;
}

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

.source-grid {
  grid-template-columns: repeat(3, 1fr);
}

.fact-card,
.graphic-card,
.chapter-nav-card {
  padding: 18px;
  border-radius: 22px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.58);
}

.fact-card h3,
.graphic-card h3 {
  margin: 0 0 10px;
  font-size: 1.04rem;
}

.fact-list,
.mixup-list {
  margin: 0;
  padding-left: 18px;
}

.graphic-card {
  overflow: hidden;
}

.graphic-card svg {
  display: block;
  width: 100%;
  height: 200px;
  margin-top: 12px;
  border-radius: 18px;
  background: linear-gradient(160deg, rgba(16, 53, 96, 0.08), rgba(15, 95, 85, 0.08));
}

.chapter-nav-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.chapter-nav-card {
  color: inherit;
  text-decoration: none;
}

.chapter-nav-card span {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.1em;
}

.materials-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  padding: 22px 0 0;
}

.materials-footer p {
  margin: 0;
  color: var(--muted);
}

.exam-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.exam-chip {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 14px;
  border-radius: 999px;
  background: rgba(217, 130, 43, 0.12);
  color: var(--text);
  font-weight: 800;
}

@media (max-width: 1080px) {
  .syllabus-teaser,
  .chapter-hero,
  .lesson-layout,
  .fact-grid,
  .graphic-grid,
  .source-grid,
  .chapter-nav-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .materials-shell,
  .page-shell {
    width: min(100% - 20px, 1240px);
  }

  .materials-header,
  .materials-nav,
  .materials-footer,
  .syllabus-card-grid {
    flex-direction: column;
    align-items: stretch;
    grid-template-columns: 1fr;
  }

  .chapter-hero,
  .syllabus-intro-card,
  .lesson-panel,
  .lesson-side-card,
  .source-card {
    padding: 18px;
  }

  .chapter-art {
    min-height: 240px;
  }

  .chapter-hero h1 {
    font-size: 2.7rem;
  }
}