/* ============================================================
   第六、第七学期跨专业课程教改 · 完整内容展示
   设计系统 —— 深色学术剧场 / Dark Academic Theatre
   ============================================================ */

:root {
  /* 底色体系 */
  --ink-0: #05070F;
  --ink-1: #0A0E1C;
  --ink-2: #101728;
  --ink-3: #161E33;
  --ink-4: #1D2740;

  /* 文字 */
  --text: #F3F0EA;
  --text-2: #A7A4B5;
  --text-3: #6E6B80;
  --text-4: #4A4860;

  /* 强调 */
  --gold: #C9A227;
  --gold-lt: #E8C766;
  --gold-dim: rgba(201, 162, 39, 0.16);
  --gold-line: rgba(201, 162, 39, 0.34);

  /* 四大学科领域色彩编码 —— 贯穿全站的稳定视觉语言 */
  --tech: #4EA8DE;
  --tech-dim: rgba(78, 168, 222, 0.14);
  --people: #E07A5F;
  --people-dim: rgba(224, 122, 95, 0.14);
  --org: #9D8DF1;
  --org-dim: rgba(157, 141, 241, 0.14);
  --skill: #2FB398;
  --skill-dim: rgba(47, 179, 152, 0.14);

  /* 线条 */
  --line: rgba(255, 255, 255, 0.09);
  --line-2: rgba(255, 255, 255, 0.16);

  /* 字体 */
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", "SimSun", "Georgia", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Helvetica Neue", sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Courier New", monospace;

  /* 尺度 */
  --nav-h: 64px;
  --maxw: 1240px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: auto; }

body {
  background: var(--ink-0);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: var(--gold); color: var(--ink-0); }

/* 细网格背景 —— 学术制图感 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.018) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
  z-index: 0;
}

/* ============================================================
   顶部导航
   ============================================================ */
.topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  z-index: 100;
  background: rgba(5, 7, 15, 0);
  transition: background .5s var(--ease), border-color .5s var(--ease);
  border-bottom: 1px solid transparent;
}
.topbar.solid {
  background: rgba(5, 7, 15, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}
.topbar { transition: background .5s var(--ease), border-color .5s var(--ease), transform .45s var(--ease); }
.topbar.hide { transform: translateY(-102%); }
.brand {
  display: flex; align-items: baseline; gap: 12px;
  font-family: var(--serif);
  font-size: 15px;
  letter-spacing: 0.08em;
}
.brand b { font-weight: 600; color: var(--text); }
.brand span { font-size: 11px; color: var(--text-3); letter-spacing: 0.16em; font-family: var(--mono); }

.topnav { display: flex; gap: 4px; }
.topnav a {
  color: var(--text-2);
  text-decoration: none;
  font-size: 13px;
  padding: 7px 14px;
  border-radius: 20px;
  transition: color .3s, background .3s;
  white-space: nowrap;
}
.topnav a:hover { color: var(--text); background: rgba(255,255,255,.05); }
.topnav a.on { color: var(--gold-lt); background: var(--gold-dim); }

.scroll-progress {
  position: fixed; top: 0; left: 0;
  height: 2px; width: 0%;
  background: linear-gradient(90deg, var(--gold), var(--gold-lt));
  z-index: 101;
}

/* 右侧章节进度点 */
.rail {
  position: fixed;
  right: 22px; top: 50%;
  transform: translateY(-50%);
  z-index: 90;
  display: flex; flex-direction: column; gap: 10px;
  align-items: flex-end;
}
.rail button {
  all: unset;
  cursor: pointer;
  display: flex; align-items: center; gap: 8px;
  flex-direction: row-reverse;
}
.rail i {
  display: block;
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--text-4);
  transition: all .35s var(--ease);
}
.rail button:hover i { background: var(--text-2); transform: scale(1.5); }
.rail button.on i { background: var(--gold); transform: scale(1.7); }
.rail em {
  font-style: normal;
  font-size: 10px;
  color: var(--text-3);
  opacity: 0;
  transform: translateX(6px);
  transition: all .3s var(--ease);
  white-space: nowrap;
  font-family: var(--mono);
  letter-spacing: .05em;
}
.rail button:hover em, .rail button.on em { opacity: 1; transform: translateX(0); }

/* ============================================================
   章节通用
   ============================================================ */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 40px; position: relative; z-index: 1; }

section {
  position: relative;
  padding: 120px 0;
  z-index: 1;
}
section.tall { min-height: 100vh; display: flex; align-items: center; }
section.sep {
  min-height: 62vh;
  display: flex; align-items: center;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(ellipse at 50% 100%, rgba(201,162,39,.09), transparent 62%),
    var(--ink-1);
}

/* 章节编号 + 标题 */
.kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 20px;
  display: flex; align-items: center; gap: 12px;
}
.kicker::before {
  content: "";
  width: 28px; height: 1px;
  background: var(--gold-line);
}
.actnum {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--gold);
  border: 1px solid var(--gold-line);
  padding: 4px 12px;
  border-radius: 3px;
}

h1 {
  font-family: var(--serif);
  font-size: clamp(48px, 7.2vw, 108px);
  line-height: 1.08;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 28px;
}
h2 {
  font-family: var(--serif);
  font-size: clamp(30px, 3.9vw, 52px);
  line-height: 1.22;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 18px;
}
h3 {
  font-family: var(--serif);
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 12px;
}
h4 {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .04em;
  margin-bottom: 8px;
  color: var(--text);
}
p { color: var(--text-2); margin-bottom: 16px; }
p.lead {
  font-size: clamp(16px, 1.35vw, 19px);
  line-height: 1.85;
  color: var(--text-2);
  max-width: 68ch;
}
p strong, li strong { color: var(--text); font-weight: 600; }
em.hl { font-style: normal; color: var(--gold-lt); }

.mono { font-family: var(--mono); }
.serif { font-family: var(--serif); }

/* 分隔线 */
.hr { height: 1px; background: var(--line); margin: 56px 0; }
.hr.short { width: 64px; background: var(--gold-line); height: 2px; margin: 32px 0; }

/* ============================================================
   HERO
   ============================================================ */
#hero {
  min-height: 100vh;
  display: flex; align-items: center;
  padding: 0;
  overflow: hidden;
}
#hero .glow {
  position: absolute;
  width: 900px; height: 900px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(201,162,39,.13), transparent 65%);
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}
#hero .ring {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  border: 1px solid var(--line);
  border-radius: 50%;
  pointer-events: none;
}
.hero-in { position: relative; z-index: 2; width: 100%; }
.hero-tag {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .32em;
  color: var(--gold);
  margin-bottom: 34px;
}
.hero-title {
  font-family: var(--serif);
  font-size: clamp(58px, 9vw, 138px);
  line-height: 1.02;
  font-weight: 600;
  letter-spacing: .04em;
  margin-bottom: 12px;
}
.hero-sub {
  font-family: var(--serif);
  font-size: clamp(20px, 2.6vw, 34px);
  color: var(--gold-lt);
  letter-spacing: .1em;
  margin-bottom: 40px;
  font-weight: 400;
}
.hero-desc {
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.9;
  color: var(--text-2);
  margin-bottom: 48px;
}
.hero-meta {
  display: flex; flex-wrap: wrap; gap: 40px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}
.hero-meta div span {
  display: block;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .2em;
  color: var(--text-3);
  margin-bottom: 6px;
}
.hero-meta div b {
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 500;
  color: var(--text);
}
.scroll-cue {
  position: absolute;
  bottom: 40px; left: 50%;
  transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 10px;
  z-index: 3;
}
.scroll-cue span {
  font-family: var(--mono);
  font-size: 10px; letter-spacing: .24em; color: var(--text-3);
}
.scroll-cue i {
  width: 1px; height: 46px;
  background: linear-gradient(var(--gold), transparent);
  animation: cue 2.2s var(--ease) infinite;
  transform-origin: top;
}
@keyframes cue {
  0% { transform: scaleY(0); opacity: 0; }
  40% { transform: scaleY(1); opacity: 1; }
  100% { transform: scaleY(1); opacity: 0; }
}

/* ============================================================
   目录 / 论证路径
   ============================================================ */
.toc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 48px;
}
.toc-cell {
  background: var(--ink-1);
  padding: 32px 28px;
  transition: background .4s var(--ease);
  position: relative;
}
.toc-cell:hover { background: var(--ink-2); }
.toc-cell .n {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--gold);
  letter-spacing: .18em;
  margin-bottom: 14px;
}
.toc-cell h4 { font-family: var(--serif); font-size: 19px; margin-bottom: 10px; font-weight: 600; }
.toc-cell p { font-size: 13.5px; line-height: 1.7; margin: 0; color: var(--text-3); }

/* ============================================================
   通用卡片
   ============================================================ */
.grid {
  display: grid;
  gap: 20px;
  margin-top: 44px;
}
.g2 { grid-template-columns: repeat(2, 1fr); }
.g3 { grid-template-columns: repeat(3, 1fr); }
.g4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 30px 28px;
  transition: border-color .4s var(--ease), transform .4s var(--ease), background .4s var(--ease);
  position: relative;
  overflow: hidden;
}
.card:hover {
  border-color: var(--line-2);
  background: var(--ink-3);
  transform: translateY(-3px);
}
.card .idx {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--text-4);
  margin-bottom: 16px;
}
.card h4 { font-family: var(--serif); font-size: 19px; margin-bottom: 12px; line-height: 1.45; }
.card p { font-size: 14px; line-height: 1.75; margin: 0; }
.card ul { list-style: none; margin-top: 14px; }
.card li {
  font-size: 13.5px;
  color: var(--text-2);
  padding-left: 16px;
  position: relative;
  margin-bottom: 8px;
  line-height: 1.7;
}
.card li::before {
  content: "";
  position: absolute; left: 0; top: 10px;
  width: 5px; height: 1px; background: var(--gold);
}

/* 领域色卡 */
.card.tech { border-left: 2px solid var(--tech); }
.card.tech .idx { color: var(--tech); }
.card.tech li::before { background: var(--tech); }
.card.people { border-left: 2px solid var(--people); }
.card.people .idx { color: var(--people); }
.card.people li::before { background: var(--people); }
.card.org { border-left: 2px solid var(--org); }
.card.org .idx { color: var(--org); }
.card.org li::before { background: var(--org); }
.card.skill { border-left: 2px solid var(--skill); }
.card.skill .idx { color: var(--skill); }
.card.skill li::before { background: var(--skill); }
.card.gold { border-left: 2px solid var(--gold); }
.card.gold .idx { color: var(--gold); }

/* 领域标签 */
.tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .14em;
  padding: 3px 10px;
  border-radius: 3px;
  border: 1px solid currentColor;
  margin-right: 6px;
  margin-bottom: 6px;
  opacity: .9;
}
.tag.t { color: var(--tech); }
.tag.p { color: var(--people); }
.tag.o { color: var(--org); }
.tag.s { color: var(--skill); }
.tag.g { color: var(--gold); }

/* ============================================================
   四大学科领域
   ============================================================ */
.domain-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 48px;
}
.domain {
  background: var(--ink-1);
  padding: 40px 30px;
  position: relative;
  transition: background .45s var(--ease);
}
.domain:hover { background: var(--ink-2); }
.domain::before {
  content: "";
  position: absolute; top: 0; left: 0; right: 0;
  height: 3px;
}
.domain.d-tech::before { background: var(--tech); }
.domain.d-people::before { background: var(--people); }
.domain.d-org::before { background: var(--org); }
.domain.d-skill::before { background: var(--skill); }
.domain .en {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .2em;
  margin-bottom: 12px;
}
.d-tech .en { color: var(--tech); }
.d-people .en { color: var(--people); }
.d-org .en { color: var(--org); }
.d-skill .en { color: var(--skill); }
.domain h3 { margin-bottom: 8px; }
.domain .q {
  font-family: var(--serif);
  font-size: 15px;
  color: var(--text);
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}
.domain p { font-size: 13.5px; margin: 0; }

/* ============================================================
   12门课程 · 横向巡游（Qissa 招牌菜手法）
   ============================================================ */
.hscroll-wrap {
  overflow: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding-top: 60px;
  padding-bottom: 40px;
}
.hscroll {
  display: flex;
  gap: 24px;
  padding: 0 40px;
  will-change: transform;
  align-items: stretch;
}
.course-card {
  flex: 0 0 440px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 30px 28px;
  display: flex;
  flex-direction: column;
  transition: border-color .4s, transform .4s;
  position: relative;
  /* 定高 + 内部滚动，保证 pin 横滚时卡片完整可见 */
  height: min(560px, calc(100vh - 330px));
  overflow-y: auto;
  overscroll-behavior: contain;
}
.course-card::-webkit-scrollbar { width: 4px; }
.course-card::-webkit-scrollbar-track { background: transparent; }
.course-card::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 2px; }
.course-card::-webkit-scrollbar-thumb:hover { background: var(--gold-line); }
.course-card::after {
  content: "";
  position: absolute; top: 0; left: 32px; right: 32px; height: 2px;
}
.course-card.c-tech::after { background: var(--tech); }
.course-card.c-people::after { background: var(--people); }
.course-card.c-org::after { background: var(--org); }
.course-card.c-skill::after { background: var(--skill); }
.course-card:hover { border-color: var(--line-2); transform: translateY(-4px); }
.cc-head { display: flex; align-items: baseline; gap: 14px; margin-bottom: 6px; }
.cc-no {
  font-family: var(--mono);
  font-size: 34px;
  font-weight: 500;
  line-height: 1;
  opacity: .28;
}
.c-tech .cc-no { color: var(--tech); opacity: .55; }
.c-people .cc-no { color: var(--people); opacity: .55; }
.c-org .cc-no { color: var(--org); opacity: .55; }
.c-skill .cc-no { color: var(--skill); opacity: .55; }
.cc-ref {
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--text-4);
  letter-spacing: .05em;
}
.course-card h3 {
  font-size: 23px;
  margin-bottom: 16px;
  line-height: 1.35;
}
.cc-tags { margin-bottom: 18px; }
.cc-meta {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: 18px;
}
.cc-meta div {
  background: var(--ink-1);
  padding: 12px 14px;
}
.cc-meta span {
  display: block;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .16em;
  color: var(--text-4);
  margin-bottom: 4px;
}
.cc-meta b { font-size: 13px; font-weight: 500; color: var(--text-2); }
.cc-body { font-size: 14px; line-height: 1.8; color: var(--text-2); flex: 1; }
.cc-body ul { list-style: none; margin-top: 10px; }
.cc-body li {
  font-size: 13.5px;
  padding-left: 15px;
  position: relative;
  margin-bottom: 7px;
  line-height: 1.7;
}
.cc-body li::before {
  content: ""; position: absolute; left: 0; top: 10px;
  width: 4px; height: 4px; border-radius: 50%;
  background: var(--gold);
}
.cc-label {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--text-4);
  margin-top: 16px;
  margin-bottom: 8px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

/* ============================================================
   表格
   ============================================================ */
.table-scroll { overflow-x: auto; margin-top: 40px; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  min-width: 720px;
}
thead th {
  text-align: left;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .16em;
  color: var(--gold);
  font-weight: 500;
  padding: 14px 16px;
  border-bottom: 1px solid var(--gold-line);
  text-transform: uppercase;
  white-space: nowrap;
}
tbody td {
  padding: 15px 16px;
  border-bottom: 1px solid var(--line);
  color: var(--text-2);
  vertical-align: top;
  line-height: 1.65;
}
tbody tr { transition: background .3s; }
tbody tr:hover { background: rgba(255,255,255,.022); }
tbody td:first-child { color: var(--text); font-weight: 500; }
tbody td .sub {
  display: block;
  font-family: var(--mono);
  font-size: 10.5px;
  color: var(--text-4);
  margin-top: 3px;
}

/* ============================================================
   时间轴 / 学期节奏
   ============================================================ */
.timeline { margin-top: 52px; position: relative; }
.timeline::before {
  content: "";
  position: absolute;
  left: 128px; top: 0; bottom: 0;
  width: 1px;
  background: var(--line);
}
.tl-row {
  display: grid;
  grid-template-columns: 128px 1fr;
  gap: 40px;
  padding: 24px 0;
  position: relative;
}
.tl-row .wk {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--gold);
  text-align: right;
  padding-top: 2px;
  letter-spacing: .06em;
}
.tl-row .dot {
  position: absolute;
  left: 124px; top: 32px;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--ink-0);
  border: 1px solid var(--gold);
}
.tl-row .dot::after {
  content: "";
  position: absolute; inset: 2px;
  border-radius: 50%;
  background: var(--gold);
}
.tl-cont h4 { font-family: var(--serif); font-size: 18px; margin-bottom: 8px; }
.tl-cont p { font-size: 14px; margin: 0; }

/* 双轨学期对照 */
.semester-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 48px;
}
.sem {
  background: var(--ink-1);
  padding: 44px 38px;
}
.sem .sno {
  font-family: var(--serif);
  font-size: 46px;
  color: var(--gold);
  opacity: .3;
  line-height: 1;
  margin-bottom: 10px;
}
.sem h3 { margin-bottom: 6px; }
.sem .sub-en {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .2em;
  color: var(--text-4);
  margin-bottom: 22px;
}
.sem ul { list-style: none; }
.sem li {
  font-size: 14px;
  color: var(--text-2);
  padding-left: 20px;
  position: relative;
  margin-bottom: 12px;
  line-height: 1.7;
}
.sem li::before {
  content: "";
  position: absolute; left: 0; top: 9px;
  width: 6px; height: 6px;
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}

/* ============================================================
   评价比例条
   ============================================================ */
.eval-bars { margin-top: 44px; }
.eval-row { margin-bottom: 26px; }
.eval-top {
  display: flex; justify-content: space-between; align-items: baseline;
  margin-bottom: 10px;
}
.eval-top b { font-size: 15px; font-weight: 500; }
.eval-top i {
  font-style: normal;
  font-family: var(--mono);
  font-size: 26px;
  color: var(--gold);
}
.eval-track {
  height: 6px;
  background: var(--ink-3);
  border-radius: 3px;
  overflow: hidden;
}
.eval-fill {
  height: 100%; width: 0;
  background: linear-gradient(90deg, var(--gold), var(--gold-lt));
  border-radius: 3px;
}
.eval-note { font-size: 13px; color: var(--text-3); margin-top: 8px; }

/* ============================================================
   数据统计
   ============================================================ */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 48px;
}
.stat {
  background: var(--ink-1);
  padding: 40px 28px;
  text-align: center;
}
.stat b {
  display: block;
  font-family: var(--serif);
  font-size: clamp(40px, 5vw, 62px);
  font-weight: 600;
  color: var(--gold);
  line-height: 1;
  margin-bottom: 12px;
}
.stat span { font-size: 13.5px; color: var(--text-2); }
.stat i {
  display: block;
  font-style: normal;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .16em;
  color: var(--text-4);
  margin-top: 8px;
}

/* ============================================================
   引用块
   ============================================================ */
blockquote {
  font-family: var(--serif);
  font-size: clamp(21px, 2.4vw, 30px);
  line-height: 1.62;
  color: var(--text);
  padding: 40px 0 40px 36px;
  border-left: 2px solid var(--gold);
  margin: 56px 0;
  max-width: 30ch;
  position: relative;
}
blockquote cite {
  display: block;
  font-family: var(--mono);
  font-style: normal;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--text-4);
  margin-top: 22px;
}

/* ============================================================
   列表（带序号）
   ============================================================ */
.numlist { list-style: none; counter-reset: nl; margin-top: 40px; }
.numlist li {
  counter-increment: nl;
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 20px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}
.numlist li:last-child { border-bottom: 1px solid var(--line); }
.numlist li::before {
  content: counter(nl, decimal-leading-zero);
  font-family: var(--mono);
  font-size: 13px;
  color: var(--gold);
  letter-spacing: .1em;
  padding-top: 3px;
}
.numlist b {
  display: block;
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text);
}
.numlist p { font-size: 14px; margin: 0; }

/* 清单 */
.checklist { list-style: none; margin-top: 32px; }
.checklist li {
  display: flex; gap: 14px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14.5px;
  color: var(--text-2);
  line-height: 1.7;
}
.checklist li::before {
  content: "";
  flex: 0 0 auto;
  width: 7px; height: 7px;
  margin-top: 9px;
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}
.checklist li b { color: var(--text); font-weight: 600; }

/* ============================================================
   分隔页
   ============================================================ */
.sep-in { width: 100%; }
.sep .act-no {
  font-family: var(--serif);
  font-size: clamp(80px, 13vw, 190px);
  line-height: .9;
  color: transparent;
  -webkit-text-stroke: 1px var(--gold-line);
  margin-bottom: 12px;
  letter-spacing: .04em;
}
.sep h2 { font-size: clamp(34px, 5vw, 66px); margin-bottom: 20px; }
.sep p { max-width: 60ch; font-size: 17px; }

/* ============================================================
   页脚
   ============================================================ */
footer {
  border-top: 1px solid var(--line);
  padding: 90px 0 60px;
  background: var(--ink-1);
  position: relative; z-index: 1;
}
.foot-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--line);
}
.foot-grid h4 {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .2em;
  color: var(--gold);
  margin-bottom: 18px;
  font-weight: 500;
}
.foot-grid li { list-style: none; font-size: 14px; color: var(--text-2); margin-bottom: 10px; line-height: 1.7; }
.foot-bot {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: 32px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--text-4);
}

/* ============================================================
   开场加载（纯 CSS 兜底退场，JS 挂掉也不会锁死页面）
   ============================================================ */
#preloader {
  position: fixed; inset: 0; z-index: 9999;
  background: var(--ink-0);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 26px;
  animation: plOut .7s var(--ease) 1.9s forwards;
}
@keyframes plOut { to { opacity: 0; visibility: hidden; } }
#preloader.gone { display: none; }
.pl-name {
  font-family: var(--serif);
  font-size: clamp(22px, 3.2vw, 38px);
  letter-spacing: .16em;
  color: var(--text);
  opacity: 0;
  animation: plIn .9s var(--ease) .15s forwards;
}
@keyframes plIn { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
.pl-bar { width: min(260px, 48vw); height: 1px; background: var(--line-2); overflow: hidden; }
.pl-bar i {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--gold), var(--gold-lt));
  animation: plBar 1.5s var(--ease) .2s forwards;
}
@keyframes plBar { to { width: 100%; } }
.pl-txt {
  font-family: var(--mono); font-size: 10px;
  letter-spacing: .3em; color: var(--text-4);
  opacity: 0; animation: plIn .9s var(--ease) .35s forwards;
}

/* ============================================================
   自定义光标
   ============================================================ */
.cursor, .cursor-dot {
  position: fixed; top: 0; left: 0;
  pointer-events: none; z-index: 9998; border-radius: 50%;
  opacity: 0;
}
.cursor {
  width: 32px; height: 32px; margin: -16px 0 0 -16px;
  border: 1px solid var(--gold-line);
  transition: width .32s var(--ease), height .32s var(--ease),
              margin .32s var(--ease), background .32s var(--ease),
              border-color .32s var(--ease), opacity .3s;
}
.cursor-dot {
  width: 4px; height: 4px; margin: -2px 0 0 -2px;
  background: var(--gold);
}
.cursor.on {
  width: 58px; height: 58px; margin: -29px 0 0 -29px;
  background: rgba(201, 162, 39, .10);
  border-color: var(--gold);
}
.cursor.on-text { width: 76px; height: 76px; margin: -38px 0 0 -38px; background: rgba(201,162,39,.14); }
body.cursor-on, body.cursor-on a, body.cursor-on button { cursor: none; }
@media (pointer: coarse), (max-width: 820px) {
  .cursor, .cursor-dot { display: none !important; }
}

/* ============================================================
   卡片聚光灯
   ============================================================ */
.card.spot::before, .toc-cell.spot::before, .domain.spot::before {
  content: "";
  position: absolute; inset: 0;
  background: radial-gradient(340px circle at var(--mx, 50%) var(--my, 50%),
              rgba(201, 162, 39, .10), transparent 62%);
  opacity: 0;
  transition: opacity .45s var(--ease);
  pointer-events: none;
  z-index: 0;
}
.card.spot:hover::before, .toc-cell.spot:hover::before, .domain.spot:hover::before { opacity: 1; }
.card.spot > *, .toc-cell.spot > *, .domain.spot > * { position: relative; z-index: 1; }

/* 3D 倾斜：去掉 CSS 的 transform 过渡，避免与 GSAP 每帧写入打架 */
.tilt {
  transform-style: preserve-3d;
  will-change: transform;
  transition: border-color .4s var(--ease), background .4s var(--ease) !important;
}
/* 横向巡游中当前卡片高亮 */
.course-card.active {
  border-color: var(--gold-line);
  box-shadow: 0 0 0 1px rgba(201, 162, 39, .18), 0 18px 50px -20px rgba(0, 0, 0, .8);
}
.course-card { transition: border-color .45s var(--ease), box-shadow .45s var(--ease), background .4s var(--ease); }

/* ============================================================
   横向巡游进度条
   ============================================================ */
.hs-bar {
  position: absolute;
  left: 40px; right: 40px; bottom: 26px;
  display: flex; align-items: center; gap: 18px;
  z-index: 3;
}
.hs-track {
  flex: 1; height: 1px;
  background: var(--line-2);
  position: relative; overflow: hidden;
}
.hs-fill {
  position: absolute; left: 0; top: 0; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--gold), var(--gold-lt));
}
.hs-num, .hs-tip {
  font-size: 10.5px; letter-spacing: .18em;
  color: var(--text-4); white-space: nowrap;
}
.hs-num { color: var(--gold); }

/* ============================================================
   回到顶部 · 环形进度
   ============================================================ */
.totop {
  all: unset;
  position: fixed; right: 26px; bottom: 26px;
  width: 50px; height: 50px; border-radius: 50%;
  z-index: 95; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  opacity: 0; transform: translateY(14px) scale(.9);
  pointer-events: none;
  transition: opacity .45s var(--ease), transform .45s var(--ease);
}
.totop.show { opacity: 1; transform: none; pointer-events: auto; }
.totop svg { position: absolute; inset: 0; width: 100%; height: 100%; transform: rotate(-90deg); }
.totop circle { fill: rgba(10, 14, 28, .78); stroke-width: 1.5; }
.totop .ring-bg { stroke: var(--line-2); }
.totop .ring-fg {
  stroke: var(--gold);
  stroke-dasharray: 131.95;
  stroke-dashoffset: 131.95;
  transition: stroke-dashoffset .2s linear;
}
.totop .arw {
  width: 8px; height: 8px;
  border-left: 1px solid var(--text);
  border-top: 1px solid var(--text);
  transform: rotate(45deg);
  margin-top: 3px;
  transition: transform .35s var(--ease);
}
.totop:hover .arw { transform: rotate(45deg) translate(-2px, -2px); border-color: var(--gold-lt); }

/* ============================================================
   时间轴生长线
   ============================================================ */
.timeline::after {
  content: "";
  position: absolute; left: 128px; top: 0;
  width: 1px; height: var(--tlh, 0%);
  background: linear-gradient(180deg, var(--gold), rgba(201, 162, 39, .22));
}

/* ============================================================
   动画初始态 —— 仅在 JS 就绪后隐藏（保证无 JS / CDN 失败时内容可读）
   ============================================================ */
.anim-ready .rv { opacity: 0; }
.anim-ready .rv-up { opacity: 0; transform: translateY(34px); }
.anim-ready .rv-left { opacity: 0; transform: translateX(-30px); }
.anim-ready .rv-scale { opacity: 0; transform: scale(.96); }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1100px) {
  .g4 { grid-template-columns: repeat(2, 1fr); }
  .g3 { grid-template-columns: repeat(2, 1fr); }
  .domain-grid { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .foot-grid { grid-template-columns: 1fr 1fr; }
  .rail { display: none; }
}
@media (max-width: 820px) {
  .wrap { padding: 0 22px; }
  section { padding: 84px 0; }
  .g2, .g3, .g4 { grid-template-columns: 1fr; }
  .domain-grid { grid-template-columns: 1fr; }
  .semester-split { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .topnav { display: none; }
  .topbar { padding: 0 20px; }
  .hscroll-wrap { min-height: auto; }
  .hscroll { padding: 0 22px; }
  .course-card { flex: 0 0 84vw; height: auto; max-height: none; overflow: visible; }
  .timeline::before, .timeline::after { left: 0; }
  .tl-row { grid-template-columns: 1fr; gap: 12px; padding-left: 26px; }
  .hs-bar { left: 22px; right: 22px; bottom: 8px; }
  .hs-tip { display: none; }
  .totop { right: 16px; bottom: 16px; width: 44px; height: 44px; }
  .tl-row .wk { text-align: left; }
  .tl-row .dot { left: -4px; }
  .foot-grid { grid-template-columns: 1fr; gap: 32px; }
  .foot-bot { flex-direction: column; gap: 12px; align-items: flex-start; }
  .hero-meta { gap: 26px; }
  blockquote { padding-left: 22px; font-size: 20px; }
}

@media (prefers-reduced-motion: reduce) {
  .anim-ready .rv, .anim-ready .rv-up,
  .anim-ready .rv-left, .anim-ready .rv-scale {
    opacity: 1 !important; transform: none !important;
  }
  .scroll-cue i { animation: none; }
}