/* 课程首页与章节入口；参考文档沿用原有阅读布局。 */
.brand-mark { display: grid; place-items: center; width: 29px; height: 29px; border-radius: 8px; color: #fff; background: #286852; font: 700 22px/1 var(--sans); }
.course-nav-link { color: var(--text-soft); font-size: 13px; white-space: nowrap; }
.nav-home { display: block; color: var(--text); font-weight: 650; padding: 8px 12px 15px; border-bottom: 1px solid var(--border); margin-bottom: 14px; }
.skip-link { position: fixed; left: 16px; top: -100px; z-index: 110; padding: 10px 16px; background: var(--bg); border: 2px solid var(--primary); }
.skip-link:focus { top: 8px; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 2px solid var(--primary); outline-offset: 4px; }
.chapter-overview { padding: 22px 24px; border: 1px solid var(--border); border-radius: 12px; background: var(--bg-soft); margin: 24px 0 36px; }
.doc .chapter-summary { color: var(--text); font-size: 18px; margin-top: 0; }
.doc .chapter-hint { font-size: 13px; color: var(--text-soft); }
.chapter-resources { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.chapter-resources a { border: 1px solid var(--border); border-radius: 6px; padding: 5px 10px; font-size: 13px; background: var(--bg); }
.course-breadcrumb { font-size: 13px; color: var(--text-soft); }
.course-page { --primary: #286852; --primary-soft: #e6efe7; }
html.dark .course-page { --primary: #90c6a4; --primary-soft: #253c2c; }

.home-page { --bg: #fafbf8; --bg-soft: #f0f3ee; --text: #202e27; --text-soft: #627067; --text-faint: #7a857d; --border: #dce3d9; --primary: #286852; --primary-soft: #e6efe7; }
html.dark .home-page { --bg: #131c17; --bg-soft: #1a2820; --text: #e0e9e2; --text-soft: #a5b6aa; --text-faint: #85998c; --border: #304336; --primary: #90c6a4; --primary-soft: #253c2c; }
.home-page .sidebar { display: none; }
.home-page .content { max-width: 1200px; width: 100%; margin: 0 auto; padding: 0 44px; min-width: 0; }
.home-page .doc { max-width: none; }
.home-page .topbar { padding: 0 max(24px, calc((100vw - 1200px) / 2 + 44px)); }
.home-page .searchbox { max-width: 290px; }
.home-page .top-actions { gap: 20px; }
.home-page .site-footer { margin: 0; padding: 28px 0; font-size: 12px; }
.course-home h1, .course-home h2, .course-home h3, .course-home p { margin: 0; padding: 0; border: 0; }
.course-home h1, .course-home h2, .course-home h3 { color: var(--text); }
.course-home h2 { font-size: 30px; line-height: 1.4; letter-spacing: -.9px; }
.course-home h3 { font-size: 18px; line-height: 1.5; }
.course-home a:hover { text-decoration: none; }
.course-home .eyebrow { font-size: 11px; font-weight: 650; letter-spacing: 1.5px; color: var(--primary); margin-bottom: 17px; }
.course-hero { display: grid; grid-template-columns: 1.25fr 1fr; gap: 72px; align-items: center; padding: 72px 0 56px; }
.course-home h1 { font-size: clamp(34px, 4.1vw, 51px); font-weight: 750; line-height: 1.3; letter-spacing: -2px; }
.accent-dot { color: var(--primary); }
.course-home .hero-lead { font-size: 16px; line-height: 1.95; color: var(--text-soft); max-width: 510px; margin-top: 23px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 29px 0 18px; }
.course-button { display: inline-flex; align-items: center; justify-content: center; gap: 20px; padding: 11px 18px; border-radius: 7px; font-size: 14px; font-weight: 600; border: 1px solid var(--border); transition: background .15s, transform .15s; }
.course-button.primary { background: var(--primary); border-color: var(--primary); color: var(--bg); }
.course-button.secondary { color: var(--text); background: var(--bg); }
.course-button:hover { transform: translateY(-2px); }
.course-button:active { transform: scale(.98); }
.course-home .hero-note { color: var(--text-faint); font-size: 12px; }
.decision-map { padding: 24px; border: 1px solid var(--border); border-radius: 15px; background: var(--bg-soft); }
.map-caption { display: flex; justify-content: space-between; align-items: center; gap: 12px; color: var(--text-soft); font-size: 11px; margin-bottom: 20px; }
.map-label { font-family: var(--mono); font-size: 9px; letter-spacing: .5px; }
.map-input, .map-output, .map-policy { padding: 12px 16px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); }
.decision-map strong, .decision-map span { display: block; }
.decision-map strong { font-size: 15px; line-height: 1.6; }
.decision-map .map-step { color: var(--primary); font-family: var(--mono); font-size: 9px; letter-spacing: .7px; margin-bottom: 4px; }
.map-input > span:last-child, .map-output > span:last-child, .map-policy > span:last-child { color: var(--text-soft); font-size: 10px; margin-top: 3px; }
.map-connector { text-align: center; font-size: 14px; color: var(--text-faint); line-height: 22px; }
.map-model { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 12px 16px; border-radius: 8px; background: #286852; color: #f3f8f4; }
.map-model strong { font-size: 22px; letter-spacing: -.5px; }
.map-model span { font-family: var(--mono); font-size: 10px; }
.course-facts { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); padding: 26px 0; }
.course-facts > div { padding: 0 22px; border-left: 1px solid var(--border); }
.course-facts > div:first-child { padding-left: 0; border: 0; }
.course-facts strong { font-size: 27px; font-weight: 650; line-height: 1.4; letter-spacing: -1px; }
.course-facts strong span { font-size: 12px; margin-left: 5px; letter-spacing: 0; color: var(--text-soft); }
.course-facts > div:last-child strong { font-size: 20px; letter-spacing: -.4px; }
.course-home .course-facts p { font-size: 11px; color: var(--text-soft); margin-top: 7px; }
.course-section { padding: 62px 0; border-bottom: 1px solid var(--border); }
.course-intro { display: grid; grid-template-columns: 1fr 1.5fr; gap: 80px; }
.intro-body p { color: var(--text-soft); font-size: 14px; line-height: 1.95; }
.intro-body p + p { margin-top: 16px; }
.section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 32px; margin-bottom: 32px; }
.section-heading > p { font-size: 12px; color: var(--text-soft); padding-bottom: 5px; max-width: 300px; }
.curriculum-group { display: grid; grid-template-columns: 164px 1fr; gap: 32px; margin-top: 30px; }
.curriculum-stage { padding-top: 18px; }
.curriculum-stage > span { color: var(--text-faint); font: 11px var(--mono); }
.curriculum-stage h3 { font-size: 15px; margin-top: 5px; }
.chapter-row { display: grid; grid-template-columns: 28px 1fr 178px 16px; align-items: center; gap: 16px; padding: 19px 4px; border-bottom: 1px solid var(--border); color: var(--text); transition: background .15s; }
.chapter-row:first-child { border-top: 1px solid var(--border); }
.chapter-row:hover { background: var(--bg-soft); }
.chapter-number { align-self: start; padding-top: 3px; font: 12px/1.7 var(--mono); color: var(--text-faint); }
.chapter-row h3 { font-size: 16px; }
.chapter-row p { color: var(--text-soft); font-size: 12px; margin-top: 6px; line-height: 1.8; }
.chapter-topics { display: flex; flex-wrap: wrap; gap: 4px 7px; }
.chapter-topics span { font-size: 10px; color: var(--text-soft); padding: 2px 6px; border: 1px solid var(--border); border-radius: 4px; }
.chapter-arrow { color: var(--primary); font-size: 19px; }
.learning-routes { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.learning-routes > a { padding: 24px; border: 1px solid var(--border); border-radius: 9px; color: var(--text); }
.learning-routes > a:hover { border-color: var(--primary); background: var(--bg-soft); }
.route-label { color: var(--primary); font-size: 11px; }
.learning-routes h3 { margin: 12px 0 8px; font-size: 17px; }
.learning-routes p { font-size: 12px; color: var(--text-soft); }
.route-chapters { display: flex; justify-content: space-between; font: 11px/1.5 var(--mono); color: var(--text-faint); margin-top: 22px; }
.route-chapters > span { color: var(--primary); font-size: 17px; }
.getting-started { display: grid; grid-template-columns: 1fr 1fr; gap: 70px; }
.getting-started > div > p:not(.eyebrow) { color: var(--text-soft); font-size: 13px; margin: 18px 0 26px; max-width: 340px; }
.start-steps > div { display: flex; gap: 18px; padding: 17px 0; border-bottom: 1px solid var(--border); }
.start-steps > div:first-child { padding-top: 0; }
.start-steps > div:last-child { border-bottom: 0; }
.start-steps > div > span { font: 12px/1.8 var(--mono); color: var(--primary); }
.start-steps h3 { font-size: 15px; }
.start-steps p { font-size: 12px; color: var(--text-soft); margin-top: 6px; line-height: 1.9; }
.reference-links { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.reference-links > a { color: var(--text); border-top: 1px solid var(--border); padding: 20px 0; }
.reference-links > a > span { font-size: 11px; color: var(--text-faint); }
.reference-links h3 { display: flex; justify-content: space-between; margin: 8px 0; font-size: 17px; }
.reference-links h3 span { color: var(--primary); }
.reference-links p { color: var(--text-soft); font-size: 12px; }
.course-home .evidence-note { padding: 16px 20px; border-radius: 7px; background: var(--bg-soft); font-size: 12px; color: var(--text-soft); margin-top: 12px; }
.course-closing { display: flex; justify-content: space-between; align-items: center; gap: 28px; padding: 48px 0; }
.course-closing h2 { font-size: 22px; margin: 8px 0; }
.course-closing p { color: var(--text-soft); font-size: 12px; }

.reading-page { --primary: #286852; --primary-soft: #e6efe7; }
html.dark .reading-page { --primary: #90c6a4; --primary-soft: #253c2c; }
.reading-page .content { min-width: 0; }
.reading-lead { color: var(--text-soft); line-height: 1.9; }
.reading-group { margin: 24px 0; border-top: 1px solid var(--border); }
.reading-group > summary, .doc .reading-group > h2 { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 20px 0; margin: 0; border: 0; font-size: 17px; font-weight: 650; }
.reading-group > summary { cursor: pointer; list-style: none; }
.reading-group > summary::-webkit-details-marker { display: none; }
.reading-group > summary::after { content: "+"; color: var(--primary); font-size: 22px; }
.reading-group[open] > summary::after { content: "−"; }
.reading-group small { color: var(--text-soft); font-size: 11px; font-weight: 400; white-space: nowrap; margin-left: auto; }
.reading-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; padding-bottom: 12px; }
.reading-card { display: grid; grid-template-columns: 23px minmax(0, 1fr) 15px; gap: 12px; padding: 19px 16px; border: 1px solid var(--border); border-radius: 8px; color: var(--text); background: var(--bg); }
.reading-card:hover { border-color: var(--primary); background: var(--bg-soft); text-decoration: none; }
.reading-card .reading-number { color: var(--primary); font: 11px/1.8 var(--mono); }
.doc .reading-card h3 { font-size: 15px; margin: 0; padding: 0; line-height: 1.6; }
.doc .reading-card p { font-size: 12px; color: var(--text-soft); margin: 8px 0 10px; line-height: 1.8; }
.reading-count { color: var(--text-faint); font-size: 10px; }
.reading-card > span:last-child { color: var(--primary); }
.reading-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 22px; margin-top: 26px; }
.reading-actions > a:last-child { font-size: 12px; }
.reading-documents { margin: 24px 0; padding: 14px 18px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg-soft); }
.reading-documents summary { cursor: pointer; font-weight: 600; }
.reading-document-list li { padding: 5px 0; overflow-wrap: anywhere; }
.reading-document-list small { display: block; color: var(--text-faint); font-size: 10px; }
.reading-missing-media { display: inline-block; color: var(--text-soft); font-size: 12px; overflow-wrap: anywhere; }
.reading-snapshot-note { font-size: 12px; color: var(--text-soft); padding: 14px 18px; background: var(--bg-soft); border-radius: 8px; }

@media (max-width: 1100px) {
  .home-page .content { padding: 0 30px; }
  .home-page .topbar { padding: 0 25px; }
  .course-hero { gap: 35px; }
  .chapter-row { grid-template-columns: 26px 1fr 125px 16px; gap: 12px; }
  .curriculum-group { grid-template-columns: 125px 1fr; gap: 24px; }
  .course-facts > div { padding: 0 16px; }
  .home-page .searchbox { max-width: 220px; }
  .home-page .top-actions { gap: 14px; }
}
@media (max-width: 820px) {
  .topbar { gap: 9px; padding: 0 16px; }
  .top-actions { gap: 8px; }
  .course-nav-link { display: none; }
  .home-page .menu-btn { display: block; }
  .home-page .sidebar.open { display: block; }
  .home-page .topbar { padding: 0 18px; }
  .home-page .searchbox { max-width: 200px; }
  .course-hero { grid-template-columns: 1fr 1fr; gap: 25px; padding: 50px 0 40px; }
  .decision-map { padding: 18px; }
  .map-caption { display: block; }
  .map-label { margin-top: 4px; }
  .course-home h1 { font-size: 34px; letter-spacing: -1.5px; }
  .course-home .hero-lead { font-size: 14px; }
  .course-facts { grid-template-columns: 1fr 1fr; gap: 24px 0; }
  .course-facts > div:nth-child(3) { padding-left: 0; border-left: 0; }
  .course-intro { gap: 36px; }
  .curriculum-group { grid-template-columns: 1fr; gap: 14px; margin-top: 24px; }
  .curriculum-stage { display: flex; align-items: center; gap: 10px; padding-top: 0; }
  .curriculum-stage h3 { margin: 0; }
  .chapter-row { grid-template-columns: 26px 1fr 150px 16px; }
  .getting-started { gap: 35px; }
}
@media (max-width: 960px) {
  .home-page .sidebar.open { display: block; }
}
@media (max-width: 600px) {
  .home-page .content { padding: 0 22px; }
  .topbar { height: 106px; flex-wrap: wrap; align-content: center; row-gap: 8px; }
  .topbar .searchbox, .home-page .topbar .searchbox { display: block; order: 3; flex: none; width: 100%; max-width: none; margin: 0; }
  .layout { padding-top: 106px; }
  .sidebar { top: 106px; height: calc(100dvh - 106px); }
  .sidebar-mask { top: 106px; }
  html { scroll-padding-top: 126px; }
  .topbar .top-actions { margin-left: auto; }
  .topbar .origin-link { display: none; }
  .home-page .top-actions { gap: 10px; }
  .course-hero { grid-template-columns: 1fr; gap: 30px; padding: 38px 0 32px; }
  .course-home h1 { font-size: 38px; }
  .hero-actions { gap: 9px; }
  .course-button { padding: 10px 13px; gap: 14px; font-size: 13px; }
  .decision-map { padding: 20px; }
  .map-caption { display: flex; }
  .course-home h2 { font-size: 26px; }
  .course-section { padding: 40px 0; }
  .course-intro, .getting-started { grid-template-columns: 1fr; gap: 24px; }
  .section-heading { display: block; margin-bottom: 24px; }
  .section-heading > p { margin-top: 12px; }
  .chapter-row { grid-template-columns: 23px 1fr 15px; gap: 11px; padding: 18px 0; }
  .chapter-topics { grid-column: 2; grid-row: 2; }
  .chapter-arrow { grid-column: 3; grid-row: 1; }
  .chapter-row p { font-size: 12px; }
  .learning-routes, .reference-links { grid-template-columns: 1fr; gap: 14px; }
  .learning-routes > a { padding: 20px; }
  .reference-links > a { padding: 16px 0; }
  .course-closing { align-items: flex-start; flex-direction: column; padding: 36px 0; gap: 20px; }
  .chapter-overview { padding: 18px; }
  .reading-grid { grid-template-columns: 1fr; }
  .reading-card { padding: 16px 13px; gap: 10px; }
  .reading-group > summary, .doc .reading-group > h2 { font-size: 15px; gap: 10px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .course-home * { transition: none !important; }
  .course-button:hover, .course-button:active { transform: none; }
}