/* ================================================================
   《数据新闻理论与实务》学习网站 · 轻盈学术风
   样式系统 v2 — light academic theme
   ================================================================
   设计原则：白色基底 · 学院蓝强调 · 柔光淡影 · 充裕留白 · 圆角收敛
   ================================================================ */

/* ===== 1. 默认主题变量覆盖 (轻盈学术) =====
   使用 body[data-theme="warm-paper"] 确保高于内联 :root 的特异性，
   无论 <link> 与 <style> 的先后顺序均能生效。            */
:root,
body[data-theme="warm-paper"] {
  /* 文字色阶 */
  --ink: #2b2d42;
  --ink-soft: #3d405b;
  --ink-soft-2: #4a4e69;
  --muted: #868ca0;

  /* 背景色阶 */
  --paper: #fafbfc;
  --paper-deep: #eef1f6;
  --surface: rgba(255, 255, 255, 0.70);
  --surface-strong: rgba(255, 255, 255, 0.86);
  --bar-bg: rgba(250, 251, 252, 0.94);
  --bg: linear-gradient(168deg, #fbfcfd 0%, #f1f4f9 55%, #eceef3 100%);

  /* 线条与阴影 */
  --line: #dde2eb;
  --shadow: 0 4px 24px rgba(43, 45, 66, 0.06);
  --shadow-sm: 0 2px 10px rgba(43, 45, 66, 0.04);
  --shadow-lg: 0 8px 36px rgba(43, 45, 66, 0.10);

  /* 强调色 */
  --red: #3d5a80;         /* 学院蓝 — 主强调 (替代原来的红) */
  --blue: #5b8fb9;         /* 天青蓝 — 次强调 */
  --gold: #94815f;         /* 柔金 — 点缀 */
  --green: #6a8e6a;        /* 苔绿 — 完成态 */
  --white: #ffffff;

  /* 色调辅助 */
  --tint-accent: rgba(61, 90, 128, 0.06);
  --tint-accent-strong: rgba(61, 90, 128, 0.10);

  /* 字体 */
  --font-body: "Noto Serif CJK SC", "Source Han Serif SC", "Songti SC", "SimSun", Georgia, "Times New Roman", serif;
  --font-display: "PingFang SC", -apple-system, "Microsoft YaHei", "Helvetica Neue", sans-serif;

  /* 圆角 */
  --r-sm: 4px;
  --r: 8px;
  --r-lg: 12px;

  /* 过渡 */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== 2. 其他主题微调 (保持各自性格，仅做轻度优雅化) ===== */
body[data-theme="minimal"] {
  --shadow: 0 2px 16px rgba(17, 17, 17, 0.04);
  --shadow-sm: 0 1px 8px rgba(17, 17, 17, 0.03);
  --shadow-lg: 0 6px 30px rgba(17, 17, 17, 0.08);
  --line: #e6e6e2;
  --bg: linear-gradient(168deg, #ffffff 0%, #f8f8f6 100%);
}
body[data-theme="dark"] {
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.30);
  --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.20);
  --shadow-lg: 0 8px 36px rgba(0, 0, 0, 0.40);
  --bg: linear-gradient(168deg, #1a1714 0%, #221d18 100%);
}
body[data-theme="ink-wash"] {
  --shadow: 0 3px 18px rgba(60, 50, 35, 0.07);
  --shadow-sm: 0 2px 10px rgba(60, 50, 35, 0.05);
  --shadow-lg: 0 6px 30px rgba(60, 50, 35, 0.10);
}
body[data-theme="vintage-editorial"] {
  --shadow: 0 3px 18px rgba(50, 38, 28, 0.06);
  --shadow-sm: 0 2px 10px rgba(50, 38, 28, 0.04);
  --shadow-lg: 0 6px 30px rgba(50, 38, 28, 0.09);
}
body[data-theme="paper-ink"] {
  --shadow: 0 3px 16px rgba(30, 25, 20, 0.05);
  --shadow-sm: 0 1px 8px rgba(30, 25, 20, 0.03);
  --shadow-lg: 0 6px 28px rgba(30, 25, 20, 0.08);
}

/* ===== 3. 全局细化 ===== */
body {
  background: var(--bg);
  background-attachment: fixed;
  font-family: var(--font-body);
  transition: background 0.3s var(--ease), color 0.3s var(--ease);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: var(--red); text-decoration: none; transition: color 0.2s var(--ease); }
a:hover { color: var(--blue); }

/* 主题选择器更精致 */
.theme-picker {
  border-radius: var(--r-sm) !important;
  font-family: var(--font-display) !important;
  font-weight: 500 !important;
  font-size: 13px !important;
  padding: 7px 12px !important;
  cursor: pointer;
}

/* ===== 4. 侧边栏 ===== */
.site-sidebar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: 264px;
  background: var(--bar-bg);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  z-index: 100;
  backdrop-filter: blur(20px) saturate(150%);
  -webkit-backdrop-filter: blur(20px) saturate(150%);
  display: flex;
  flex-direction: column;
  transition: transform 0.28s var(--ease);
  font-family: var(--font-display);
  box-shadow: 1px 0 0 var(--line);
}

.sidebar-header {
  padding: 22px 20px 16px;
  border-bottom: 1px solid var(--line);
  flex-shrink: 0;
}
.sidebar-header .logo {
  display: flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
}
.sidebar-header .logo-icon {
  width: 36px; height: 36px;
  display: grid; place-items: center;
  background: var(--red);
  color: var(--white);
  border-radius: var(--r-sm);
  font: 800 16px/1 var(--font-display);
  flex-shrink: 0;
  letter-spacing: -0.02em;
}
.sidebar-header h2 {
  margin: 0;
  font: 700 15px/1.3 var(--font-display);
  color: var(--ink);
  letter-spacing: -0.01em;
}
.sidebar-header .subtitle {
  display: block;
  margin-top: 2px;
  font: 400 11px/1.3 var(--font-display);
  color: var(--muted);
  letter-spacing: 0.02em;
}

/* 侧边栏导航 */
.sidebar-nav {
  flex: 1;
  padding: 10px 8px;
  overflow-y: auto;
}
.sidebar-nav .nav-section-label {
  padding: 12px 12px 5px;
  font: 600 10px/1 var(--font-display);
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.sidebar-nav .nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-radius: var(--r-sm);
  text-decoration: none;
  color: var(--ink-soft);
  font: 500 13px/1.4 var(--font-display);
  transition: all 0.18s var(--ease);
  position: relative;
}
.sidebar-nav .nav-item:hover {
  background: var(--tint-accent);
  color: var(--ink);
}
.sidebar-nav .nav-item.active {
  background: var(--tint-accent-strong);
  color: var(--red);
  font-weight: 600;
}
.sidebar-nav .nav-item.active::before {
  content: '';
  position: absolute;
  left: -8px; top: 50%;
  transform: translateY(-50%);
  width: 3px; height: 56%;
  background: var(--red);
  border-radius: 0 3px 3px 0;
}
.sidebar-nav .nav-item .nav-icon {
  width: 18px; text-align: center;
  font-size: 13px; flex-shrink: 0;
  font-weight: 600;
}
.sidebar-nav .nav-item .nav-check {
  margin-left: auto;
  width: 16px; height: 16px;
  border-radius: 50%;
  border: 1.5px solid var(--line);
  display: grid; place-items: center;
  font-size: 9px;
  flex-shrink: 0;
  transition: all 0.2s var(--ease);
  color: transparent;
}
.sidebar-nav .nav-item.visited .nav-check {
  background: var(--green);
  border-color: var(--green);
  color: var(--white);
}
.sidebar-nav .nav-divider {
  height: 1px;
  background: var(--line);
  margin: 6px 12px;
}

/* 侧边栏底部：搜索 + 进度 */
.sidebar-footer {
  padding: 12px 16px 16px;
  border-top: 1px solid var(--line);
  flex-shrink: 0;
}
.sidebar-search {
  position: relative;
  margin-bottom: 12px;
}
.sidebar-search input {
  width: 100%;
  padding: 8px 12px 8px 32px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--surface-strong);
  color: var(--ink);
  font: 400 13px/1.4 var(--font-display);
  outline: none;
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.sidebar-search input:focus {
  border-color: var(--red);
  box-shadow: 0 0 0 3px var(--tint-accent-strong);
}
.sidebar-search input::placeholder {
  color: var(--muted);
}
.sidebar-search .search-icon {
  position: absolute;
  left: 9px; top: 50%;
  transform: translateY(-50%);
  font-size: 13px;
  color: var(--muted);
  pointer-events: none;
}
.search-results {
  margin-top: 4px;
  max-height: 220px;
  overflow-y: auto;
  display: none;
  border-radius: var(--r-sm);
}
.search-results.show {
  display: block;
}
.search-result-item {
  display: block;
  padding: 7px 10px;
  border-radius: var(--r-sm);
  text-decoration: none;
  color: var(--ink-soft);
  font: 400 12px/1.4 var(--font-display);
  transition: background 0.15s var(--ease);
}
.search-result-item:hover {
  background: var(--tint-accent);
}
.search-result-item .sr-chapter {
  color: var(--muted);
  font-size: 10px;
  margin-bottom: 1px;
  font-weight: 600;
  letter-spacing: 0.02em;
}
.search-result-item mark {
  background: var(--tint-accent-strong);
  color: var(--red);
  border-radius: 2px;
  padding: 0 2px;
}

.progress-widget {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 11px 13px;
}
.progress-widget .progress-label {
  font: 600 11px/1 var(--font-display);
  color: var(--muted);
  margin-bottom: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  letter-spacing: 0.02em;
}
.progress-widget .progress-count {
  font: 700 14px/1 var(--font-display);
  color: var(--red);
}
.progress-bar {
  height: 5px;
  background: var(--paper-deep);
  border-radius: 3px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--blue), var(--red));
  border-radius: 3px;
  transition: width 0.5s var(--ease);
  width: 0%;
}
.progress-text {
  margin-top: 6px;
  font: 400 10px/1.3 var(--font-display);
  color: var(--muted);
}

/* 移动端汉堡按钮 */
.sidebar-toggle {
  display: none;
  position: fixed;
  top: 12px; left: 12px;
  z-index: 110;
  width: 40px; height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--bar-bg);
  backdrop-filter: blur(10px);
  color: var(--ink);
  cursor: pointer;
  font-size: 18px;
  align-items: center;
  justify-content: center;
  transition: all 0.2s var(--ease);
}
.sidebar-toggle:hover {
  border-color: var(--red);
  color: var(--red);
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 99;
  background: rgba(43, 45, 66, 0.25);
  backdrop-filter: blur(3px);
}
.sidebar-overlay.active {
  display: block;
}

/* 阅读进度条（页面顶部） */
.read-progress-bar {
  position: fixed;
  top: 0; left: 0;
  width: 0%;
  height: 2px;
  background: linear-gradient(90deg, var(--blue), var(--red));
  z-index: 200;
  transition: width 0.08s linear;
}

/* 内容区域偏移 */
body.has-sidebar {
  padding-left: 264px;
}

/* 桌面端隐藏汉堡按钮 */
@media (min-width: 881px) {
  .sidebar-toggle { display: none !important; }
}

/* 移动端：侧边栏变为抽屉 */
@media (max-width: 880px) {
  body.has-sidebar {
    padding-left: 0;
  }
  .site-sidebar {
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }
  .site-sidebar.open {
    transform: translateX(0);
  }
  .sidebar-toggle {
    display: flex;
  }
}

/* ===== 5. 侧边栏主题选择器 ===== */
.sidebar-theme-row {
  display: flex;
  gap: 6px;
  padding: 0 16px 14px;
  flex-wrap: wrap;
}
.sidebar-theme-btn {
  width: 24px; height: 24px;
  border-radius: 50%;
  border: 2px solid var(--line);
  cursor: pointer;
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
  padding: 0;
}
.sidebar-theme-btn:hover {
  transform: scale(1.12);
}
.sidebar-theme-btn.active {
  border-color: var(--ink);
  box-shadow: 0 0 0 2px var(--white), 0 0 0 4px var(--red);
}
.sidebar-theme-btn[data-t="warm-paper"] { background: linear-gradient(135deg, #fbfcfd, #3d5a80); }
.sidebar-theme-btn[data-t="minimal"] { background: #fff; border-color: #ccc; }
.sidebar-theme-btn[data-t="dark"] { background: linear-gradient(135deg, #221d18, #d9a441); }
.sidebar-theme-btn[data-t="ink-wash"] { background: linear-gradient(135deg, #f4f0e6, #1a1a1a); }
.sidebar-theme-btn[data-t="vintage-editorial"] { background: linear-gradient(135deg, #f5f3ee, #c05a4a); }
.sidebar-theme-btn[data-t="paper-ink"] { background: linear-gradient(135deg, #faf9f7, #b53a3a); }


/* ===== 6. 首页样式 ===== */
.landing-hero {
  text-align: center;
  padding: 72px 24px 52px;
  position: relative;
  overflow: hidden;
}
.landing-hero::before {
  content: '';
  position: absolute;
  top: -30%; left: 50%;
  transform: translateX(-50%);
  width: 520px; height: 520px;
  background: radial-gradient(circle, var(--tint-accent-strong) 0%, transparent 60%);
  pointer-events: none;
  border-radius: 50%;
}
.landing-hero .hero-badge {
  display: inline-block;
  padding: 5px 16px;
  background: var(--tint-accent-strong);
  border: 1px solid var(--line);
  border-radius: 20px;
  font: 500 12px/1.4 var(--font-display);
  color: var(--red);
  margin-bottom: 22px;
  position: relative;
  letter-spacing: 0.02em;
}
.landing-hero h1 {
  margin: 0 0 14px;
  font: 700 clamp(34px, 5.5vw, 60px)/1.12 var(--font-display);
  color: var(--ink);
  position: relative;
  letter-spacing: -0.02em;
}
.landing-hero .hero-sub {
  margin: 0 auto 30px;
  max-width: 560px;
  font: 400 17px/1.7 var(--font-body);
  color: var(--ink-soft);
  position: relative;
}
.landing-hero .hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  background: var(--red);
  color: var(--white);
  border: none;
  border-radius: var(--r);
  font: 600 15px/1 var(--font-display);
  text-decoration: none;
  cursor: pointer;
  transition: all 0.22s var(--ease);
  letter-spacing: 0.01em;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(61, 90, 128, 0.25);
  color: var(--white);
}
.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  background: var(--surface-strong);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: var(--r);
  font: 600 15px/1 var(--font-display);
  text-decoration: none;
  cursor: pointer;
  transition: all 0.22s var(--ease);
}
.btn-secondary:hover {
  border-color: var(--red);
  color: var(--red);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* 首页：进度仪表盘 */
.landing-dashboard {
  max-width: 720px;
  margin: 0 auto 44px;
  padding: 0 24px;
}
.dashboard-card {
  background: var(--surface-strong);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 26px 30px;
  display: flex;
  align-items: center;
  gap: 26px;
  flex-wrap: wrap;
  box-shadow: var(--shadow-sm);
}
.dashboard-card .dash-ring {
  width: 84px; height: 84px;
  position: relative;
  flex-shrink: 0;
}
.dashboard-card .dash-ring svg {
  width: 100%; height: 100%;
  transform: rotate(-90deg);
}
.dashboard-card .dash-ring circle {
  fill: none;
  stroke-width: 7;
  stroke-linecap: round;
}
.dashboard-card .dash-ring .ring-bg {
  stroke: var(--paper-deep);
}
.dashboard-card .dash-ring .ring-fill {
  stroke: var(--red);
  transition: stroke-dashoffset 0.6s var(--ease);
}
.dashboard-card .dash-ring .ring-text {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font: 700 20px/1 var(--font-display);
  color: var(--red);
}
.dashboard-card .dash-info {
  flex: 1;
  min-width: 200px;
}
.dashboard-card .dash-info h3 {
  margin: 0 0 5px;
  font: 700 18px/1.2 var(--font-display);
  color: var(--ink);
}
.dashboard-card .dash-info p {
  margin: 0;
  font: 400 14px/1.6 var(--font-body);
  color: var(--ink-soft);
}
.dashboard-card .dash-info .dash-stats {
  display: flex;
  gap: 18px;
  margin-top: 10px;
  flex-wrap: wrap;
}
.dashboard-card .dash-info .dash-stat {
  font: 500 12px/1.3 var(--font-display);
  color: var(--muted);
}
.dashboard-card .dash-info .dash-stat strong {
  font-size: 16px;
  color: var(--ink);
  font-weight: 700;
}

/* 首页：章节卡片网格 */
.landing-chapters {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px 52px;
}
.landing-chapters h2 {
  margin: 0 0 24px;
  font: 700 26px/1.15 var(--font-display);
  color: var(--ink);
  text-align: center;
  letter-spacing: -0.01em;
}
.chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 18px;
}
.chapter-card {
  display: block;
  text-decoration: none;
  background: var(--surface-strong);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 26px 22px;
  transition: all 0.25s var(--ease);
  position: relative;
  overflow: hidden;
}
.chapter-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 3px;
  background: var(--red);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
  border-radius: var(--r-lg) var(--r-lg) 0 0;
}
.chapter-card:hover {
  transform: translateY(-3px);
  border-color: var(--red);
  box-shadow: var(--shadow);
  background: var(--white);
}
.chapter-card:hover::before {
  transform: scaleX(1);
}
.chapter-card .cc-num {
  display: inline-block;
  padding: 2px 10px;
  background: var(--tint-accent-strong);
  color: var(--red);
  font: 600 12px/1.3 var(--font-display);
  border-radius: var(--r-sm);
  margin-bottom: 12px;
  letter-spacing: 0.01em;
}
.chapter-card .cc-title {
  margin: 0 0 7px;
  font: 700 18px/1.2 var(--font-display);
  color: var(--ink);
  letter-spacing: -0.01em;
}
.chapter-card .cc-desc {
  margin: 0 0 14px;
  font: 400 14px/1.6 var(--font-body);
  color: var(--ink-soft);
}
.chapter-card .cc-tags {
  display: flex;
  gap: 5px;
  flex-wrap: wrap;
}
.chapter-card .cc-tag {
  padding: 2px 9px;
  background: var(--paper-deep);
  color: var(--muted);
  font: 500 11px/1.3 var(--font-display);
  border-radius: var(--r-sm);
}
.chapter-card .cc-status {
  position: absolute;
  top: 14px; right: 14px;
  width: 22px; height: 22px;
  border-radius: 50%;
  border: 1.5px solid var(--line);
  display: grid; place-items: center;
  font-size: 11px;
  transition: all 0.2s var(--ease);
  color: transparent;
}
.chapter-card.visited .cc-status {
  background: var(--green);
  border-color: var(--green);
  color: var(--white);
}

/* 首页：功能亮点 */
.landing-features {
  max-width: 940px;
  margin: 0 auto;
  padding: 0 24px 72px;
}
.landing-features h2 {
  margin: 0 0 24px;
  font: 700 26px/1.15 var(--font-display);
  color: var(--ink);
  text-align: center;
  letter-spacing: -0.01em;
}
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 16px;
}
.feature-card {
  text-align: center;
  padding: 24px 18px;
  background: var(--surface-strong);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}
.feature-card .fc-icon {
  font-size: 32px;
  margin-bottom: 12px;
}
.feature-card h3 {
  margin: 0 0 7px;
  font: 700 15px/1.2 var(--font-display);
  color: var(--ink);
}
.feature-card p {
  margin: 0;
  font: 400 13px/1.6 var(--font-body);
  color: var(--ink-soft);
}

/* 首页 footer */
.landing-footer {
  text-align: center;
  padding: 36px 24px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font: 400 12px/1.7 var(--font-display);
}
.landing-footer a {
  color: var(--red);
  text-decoration: none;
}
.landing-footer a:hover {
  text-decoration: underline;
}


/* ===== 7. 章节页面组件覆盖 =====
   以下覆盖各章节内联 <style> 中的组件样式，
   通过 source order 优先级（site.css 在 <style> 之后加载）生效。
   对于 index.html（link 在 style 之前），使用 body 属性选择器确保优先级。     */

/* 页面容器 */
.page {
  padding: 28px 0 52px !important;
}

/* Top bar */
.top-bar a {
  font-weight: 600 !important;
  color: var(--red) !important;
}

/* 章节徽章 — 更柔和 */
.ch-badge {
  padding: 4px 14px !important;
  background: var(--red) !important;
  color: var(--white) !important;
  font: 600 14px/1.3 var(--font-display) !important;
  border-radius: var(--r-sm) !important;
  margin-bottom: 14px !important;
  letter-spacing: 0.02em;
}

/* 章节头部 */
.ch-header {
  padding: 20px 0 24px !important;
  border-bottom: 1px solid var(--line) !important;
}
.ch-header h1 {
  font: 700 clamp(30px, 5vw, 48px)/1.12 var(--font-display) !important;
  letter-spacing: -0.02em !important;
}
.ch-header .meta {
  color: var(--muted) !important;
  font: 400 13px/1.5 var(--font-display) !important;
  margin-bottom: 14px !important;
}
.ch-header .core {
  background: var(--surface-strong) !important;
  padding: 18px 22px !important;
  border-left: 4px solid var(--red) !important;
  border-radius: 0 var(--r) var(--r) 0 !important;
  font-size: 16px !important;
  line-height: 1.75 !important;
  color: var(--ink-soft) !important;
  font-family: var(--font-body) !important;
}

/* 标签栏 — 改为底栏式优雅风格 */
.tabs {
  position: sticky !important;
  top: 0 !important;
  z-index: 50 !important;
  display: grid !important;
  gap: 4px !important;
  padding: 6px !important;
  margin: 18px 0 26px !important;
  border: 1px solid var(--line) !important;
  background: var(--bar-bg) !important;
  backdrop-filter: blur(14px) !important;
  -webkit-backdrop-filter: blur(14px) !important;
  border-radius: var(--r) !important;
  box-shadow: var(--shadow-sm) !important;
}
.tab {
  min-height: 44px !important;
  border: 0 !important;
  border-radius: var(--r-sm) !important;
  background: transparent !important;
  cursor: pointer !important;
  font: 600 13px/1.2 var(--font-display) !important;
  color: var(--ink-soft) !important;
  transition: all 0.2s var(--ease) !important;
}
.tab:hover {
  background: var(--tint-accent) !important;
  color: var(--ink) !important;
}
.tab[aria-selected="true"] {
  color: var(--white) !important;
  background: var(--red) !important;
  font-weight: 600 !important;
}

/* 面板动画 */
.panel {
  animation: rise 0.36s var(--ease) both !important;
}
@keyframes rise {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 区块标题 */
.section-title {
  margin: 0 0 16px !important;
  font: 700 24px/1.15 var(--font-display) !important;
  color: var(--ink) !important;
  letter-spacing: -0.01em !important;
}
.section-lead {
  margin: 0 0 22px !important;
  color: var(--ink-soft) !important;
  font-size: 16px !important;
  line-height: 1.75 !important;
  font-family: var(--font-body) !important;
}

/* 网格 */
.grid {
  gap: 16px !important;
}

/* 卡片 — 更通透、更圆角 */
.card {
  padding: 22px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  position: relative !important;
  transition: all 0.25s var(--ease) !important;
  box-shadow: var(--shadow-sm) !important;
}
.card:hover {
  border-color: var(--red) !important;
  box-shadow: var(--shadow) !important;
  transform: translateY(-2px);
}
.card h3 {
  margin: 0 0 10px !important;
  font: 700 17px/1.25 var(--font-display) !important;
  color: var(--red) !important;
  letter-spacing: -0.01em !important;
}
.card p {
  margin: 0 !important;
  color: var(--ink-soft-2) !important;
  font-size: 15px !important;
  line-height: 1.7 !important;
  font-family: var(--font-body) !important;
}
.card .tag {
  display: inline-block !important;
  margin-top: 10px !important;
  padding: 2px 10px !important;
  background: var(--tint-accent-strong) !important;
  color: var(--red) !important;
  font: 500 11px/1.4 var(--font-display) !important;
  border-radius: var(--r-sm) !important;
  letter-spacing: 0.01em;
}

/* 概念列表 */
.concept-list {
  gap: 8px !important;
}
.concept-item {
  padding: 14px 18px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  cursor: pointer !important;
  transition: all 0.2s var(--ease) !important;
}
.concept-item:hover {
  background: var(--white) !important;
  border-color: var(--red) !important;
  box-shadow: var(--shadow-sm) !important;
}
.concept-item .term {
  font: 700 16px/1.3 var(--font-display) !important;
  color: var(--red) !important;
}
.concept-item .def {
  margin-top: 6px !important;
  color: var(--ink-soft-2) !important;
  font-size: 14px !important;
  line-height: 1.65 !important;
  font-family: var(--font-body) !important;
}
.concept-item .ch-ref {
  display: inline-block !important;
  margin-top: 6px !important;
  color: var(--muted) !important;
  font: 400 11px/1.3 var(--font-display) !important;
}

/* 思维模型卡 */
.model-card {
  padding: 24px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  text-align: center !important;
  box-shadow: var(--shadow-sm) !important;
}
.model-card .icon {
  font-size: 36px !important;
  margin-bottom: 10px !important;
}
.model-card h3 {
  margin: 0 0 8px !important;
  font: 700 17px/1.2 var(--font-display) !important;
  color: var(--ink) !important;
}
.model-card p {
  margin: 0 !important;
  color: var(--ink-soft-2) !important;
  font-size: 15px !important;
  line-height: 1.7 !important;
  font-family: var(--font-body) !important;
}

/* 警示卡 */
.warn-card {
  padding: 20px !important;
  border: 1px solid var(--line) !important;
  border-left: 4px solid var(--red) !important;
  background: var(--surface-strong) !important;
  border-radius: 0 var(--r) var(--r) 0 !important;
  box-shadow: var(--shadow-sm) !important;
}
.warn-card h3 {
  margin: 0 0 7px !important;
  font: 700 16px/1.2 var(--font-display) !important;
  color: var(--red) !important;
}
.warn-card p {
  margin: 0 !important;
  color: var(--ink-soft-2) !important;
  font-size: 14px !important;
  line-height: 1.65 !important;
  font-family: var(--font-body) !important;
}
.warn-card .reason {
  margin: 7px 0 0 !important;
  padding-top: 7px !important;
  border-top: 1px dashed var(--line) !important;
  color: var(--muted) !important;
  font-size: 13px !important;
  line-height: 1.5 !important;
  font-family: var(--font-display) !important;
}

/* 案例研究 */
.case-study {
  padding: 26px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r-lg) !important;
  box-shadow: var(--shadow-sm) !important;
}
.case-study .case-label {
  display: inline-block !important;
  padding: 2px 11px !important;
  background: var(--blue) !important;
  color: var(--white) !important;
  font: 500 11px/1.3 var(--font-display) !important;
  border-radius: var(--r-sm) !important;
  margin-bottom: 10px !important;
  letter-spacing: 0.02em;
}
.case-study h3 {
  margin: 0 0 10px !important;
  font: 700 20px/1.2 var(--font-display) !important;
  color: var(--ink) !important;
}
.case-study .case-body {
  color: var(--ink-soft-2) !important;
  font-size: 16px !important;
  line-height: 1.75 !important;
  font-family: var(--font-body) !important;
}
.case-study .flow span {
  padding: 5px 12px !important;
  background: var(--tint-accent-strong) !important;
  font: 500 12px/1.3 var(--font-display) !important;
  border-radius: var(--r-sm) !important;
  color: var(--ink) !important;
}
.case-study .flow .arrow {
  background: none !important;
  color: var(--red) !important;
  font-size: 16px !important;
}

/* 要点列表 */
.takeaway-list {
  gap: 8px !important;
}
.takeaway-list li {
  padding: 14px 18px 14px 56px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  font-size: 15px !important;
  line-height: 1.65 !important;
  font-family: var(--font-body) !important;
  color: var(--ink-soft-2) !important;
  box-shadow: var(--shadow-sm) !important;
}
.takeaway-list li::before {
  content: counter(tk) !important;
  position: absolute !important;
  left: 12px !important;
  top: 12px !important;
  width: 30px !important;
  height: 30px !important;
  display: grid !important;
  place-items: center !important;
  color: var(--white) !important;
  background: var(--red) !important;
  font: 700 15px/1 var(--font-display) !important;
  border-radius: 50% !important;
}

/* 章节导航 */
.ch-nav {
  display: flex !important;
  justify-content: space-between !important;
  align-items: center !important;
  margin-top: 36px !important;
  padding-top: 18px !important;
  border-top: 1px solid var(--line) !important;
}
.ch-nav a {
  padding: 9px 18px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  color: var(--ink) !important;
  text-decoration: none !important;
  font: 600 14px/1.3 var(--font-display) !important;
  border-radius: var(--r) !important;
  transition: all 0.2s var(--ease) !important;
}
.ch-nav a:hover {
  border-color: var(--red) !important;
  color: var(--red) !important;
  box-shadow: var(--shadow-sm) !important;
}
.ch-nav .disabled {
  opacity: 0.3 !important;
  pointer-events: none !important;
}

/* 页脚 */
.footer {
  margin-top: 18px !important;
  color: var(--muted) !important;
  font: 400 12px/1.7 var(--font-display) !important;
  text-align: center !important;
}

/* 追问按钮 */
.deep-dive-btn {
  position: absolute !important;
  bottom: 8px !important;
  right: 8px !important;
  width: 24px !important;
  height: 24px !important;
  border-radius: 50% !important;
  border: 1px solid var(--line) !important;
  background: var(--white) !important;
  color: var(--muted) !important;
  cursor: pointer !important;
  font: 600 12px/1 var(--font-display) !important;
  opacity: 0 !important;
  transition: opacity 0.2s var(--ease) !important;
  z-index: 2 !important;
}
.card:hover .deep-dive-btn,
.concept-item:hover .deep-dive-btn,
.warn-card:hover .deep-dive-btn,
.case-study:hover .deep-dive-btn,
.takeaway-list li:hover .deep-dive-btn {
  opacity: 0.5 !important;
}
.deep-dive-btn:hover {
  opacity: 1 !important;
  background: var(--red) !important;
  color: var(--white) !important;
  border-color: var(--red) !important;
}

/* 追问弹窗 */
.dd-overlay {
  display: none !important;
  position: fixed !important;
  inset: 0 !important;
  z-index: 200 !important;
  background: rgba(43, 45, 66, 0.30) !important;
  backdrop-filter: blur(4px) !important;
  align-items: center !important;
  justify-content: center !important;
}
.dd-overlay.active {
  display: flex !important;
}
.dd-popover {
  width: min(480px, calc(100% - 32px)) !important;
  padding: 26px !important;
  background: var(--paper) !important;
  border: 1px solid var(--line) !important;
  box-shadow: var(--shadow-lg) !important;
  border-radius: var(--r-lg) !important;
}
.dd-popover .dd-title {
  margin: 0 0 5px !important;
  font: 700 20px/1.2 var(--font-display) !important;
  color: var(--ink) !important;
}
.dd-popover .dd-ctx {
  margin: 0 0 14px !important;
  color: var(--muted) !important;
  font: 400 12px/1.5 var(--font-display) !important;
}
.dd-popover textarea {
  width: 100% !important;
  min-height: 64px !important;
  padding: 10px 12px !important;
  border: 1px solid var(--line) !important;
  border-radius: var(--r) !important;
  font: 400 15px/1.6 var(--font-display) !important;
  color: var(--ink) !important;
  background: var(--white) !important;
  resize: vertical !important;
  margin-bottom: 12px !important;
  outline: none !important;
  transition: border-color 0.2s var(--ease) !important;
}
.dd-popover textarea:focus {
  border-color: var(--red) !important;
  box-shadow: 0 0 0 3px var(--tint-accent-strong) !important;
}
.dd-popover .dd-actions {
  display: flex !important;
  gap: 8px !important;
}
.dd-popover .dd-submit {
  padding: 9px 20px !important;
  border: 0 !important;
  border-radius: var(--r) !important;
  background: var(--red) !important;
  color: var(--white) !important;
  cursor: pointer !important;
  font: 600 14px/1.3 var(--font-display) !important;
  transition: all 0.2s var(--ease) !important;
}
.dd-popover .dd-submit:hover {
  box-shadow: 0 4px 16px rgba(61, 90, 128, 0.25) !important;
}
.dd-popover .dd-cancel {
  padding: 9px 16px !important;
  border: 1px solid var(--line) !important;
  border-radius: var(--r) !important;
  background: transparent !important;
  cursor: pointer !important;
  font: 600 14px/1.3 var(--font-display) !important;
  color: var(--muted) !important;
  transition: all 0.2s var(--ease) !important;
}
.dd-popover .dd-cancel:hover {
  color: var(--ink) !important;
  border-color: var(--ink-soft) !important;
}

/* 追问 Toast */
.dd-toast {
  position: fixed !important;
  bottom: 28px !important;
  left: 50% !important;
  transform: translateX(-50%) !important;
  padding: 12px 24px !important;
  background: var(--ink) !important;
  color: var(--white) !important;
  border-radius: var(--r) !important;
  font: 500 13px/1.4 var(--font-display) !important;
  opacity: 0 !important;
  transition: opacity 0.3s var(--ease) !important;
  pointer-events: none !important;
  z-index: 300 !important;
  box-shadow: var(--shadow-lg) !important;
}
.dd-toast.show {
  opacity: 1 !important;
}

/* ===== 8. 概述页特殊组件覆盖 ===== */

/* Hero 区 */
.hero {
  min-height: 42vh !important;
  padding: 30px 0 26px !important;
}
.eyebrow {
  margin: 0 0 14px !important;
  color: var(--red) !important;
  font: 600 13px/1.3 var(--font-display) !important;
  letter-spacing: 0.03em !important;
}
.hero h1,
h1 {
  font-weight: 700 !important;
  letter-spacing: -0.02em !important;
}
.hero .lede {
  color: var(--ink-soft) !important;
  font-size: 18px !important;
  line-height: 1.7 !important;
  font-family: var(--font-body) !important;
}
.thesis {
  border-left: 4px solid var(--red) !important;
  background: var(--surface-strong) !important;
  padding: 20px 22px !important;
  box-shadow: var(--shadow-sm) !important;
  border-radius: 0 var(--r) var(--r) 0 !important;
}
.thesis strong {
  font: 700 16px/1.2 var(--font-display) !important;
  color: var(--ink) !important;
  margin-bottom: 10px !important;
}
.thesis span {
  color: var(--ink-soft-2) !important;
  font-size: 16px !important;
  line-height: 1.7 !important;
  font-family: var(--font-body) !important;
}

/* 概述页 note 卡片 */
.note {
  min-height: auto !important;
  padding: 20px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  box-shadow: var(--shadow-sm) !important;
  transition: all 0.25s var(--ease) !important;
}
.note:hover {
  border-color: var(--red) !important;
  box-shadow: var(--shadow) !important;
}
.note h3 {
  margin: 0 0 10px !important;
  font: 700 18px/1.2 var(--font-display) !important;
  color: var(--ink) !important;
}
.note p {
  margin: 0 !important;
  color: var(--ink-soft-2) !important;
  font-size: 15px !important;
  line-height: 1.65 !important;
  font-family: var(--font-body) !important;
}
.note .when {
  margin-top: 8px !important;
  color: var(--muted) !important;
  font: 500 12px/1.5 var(--font-display) !important;
}

/* 章节列表行 */
.chapter-row {
  display: grid !important;
  grid-template-columns: 48px 1fr !important;
  gap: 12px !important;
  align-items: baseline !important;
  padding: 8px 0 !important;
  border-bottom: 1px solid var(--line) !important;
  transition: background 0.2s var(--ease) !important;
  border-radius: var(--r-sm) !important;
}
.chapter-row:hover {
  background: var(--tint-accent) !important;
}
.chapter-row .ch-label {
  color: var(--red) !important;
  font: 600 13px/1.3 var(--font-display) !important;
}
.chapter-row h3 {
  margin: 0 0 2px !important;
  font: 700 16px/1.25 var(--font-display) !important;
  color: var(--ink) !important;
}
.chapter-row .ch-role {
  color: var(--muted) !important;
  font-size: 14px !important;
  line-height: 1.5 !important;
  font-family: var(--font-body) !important;
}
.chapter-row.concept-hi {
  background: var(--tint-accent-strong) !important;
}

/* 概念按钮 */
.concept-btn {
  min-height: 46px !important;
  padding: 8px 12px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  cursor: pointer !important;
  font: 500 13px/1.3 var(--font-display) !important;
  color: var(--ink-soft) !important;
  border-radius: var(--r) !important;
  transition: all 0.2s var(--ease) !important;
}
.concept-btn:hover {
  border-color: var(--red) !important;
  color: var(--red) !important;
}
.concept-btn.active {
  color: var(--white) !important;
  background: var(--red) !important;
  border-color: var(--red) !important;
}

/* 决策规则 */
.rules li {
  padding: 13px 16px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  font-size: 15px !important;
  line-height: 1.65 !important;
  font-family: var(--font-body) !important;
  color: var(--ink-soft-2) !important;
  box-shadow: var(--shadow-sm) !important;
}
.rules li strong {
  color: var(--red) !important;
  font-weight: 700 !important;
}
.rules li em {
  display: block !important;
  margin-top: 4px !important;
  color: var(--muted) !important;
  font-size: 13px !important;
  font-style: normal !important;
  font-family: var(--font-display) !important;
}

/* 自检问题 */
.question {
  display: grid !important;
  grid-template-columns: 48px 1fr !important;
  gap: 14px !important;
  align-items: center !important;
  padding: 16px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  box-shadow: var(--shadow-sm) !important;
  transition: all 0.25s var(--ease) !important;
}
.question:hover {
  border-color: var(--red) !important;
  box-shadow: var(--shadow) !important;
}
.question::before {
  counter-increment: q !important;
  content: counter(q) !important;
  display: grid !important;
  place-items: center !important;
  width: 42px !important;
  height: 42px !important;
  color: var(--white) !important;
  background: var(--red) !important;
  font: 700 20px/1 var(--font-display) !important;
  border-radius: 50% !important;
}
.question h3 {
  margin: 0 0 3px !important;
  font: 700 16px/1.25 var(--font-display) !important;
  color: var(--ink) !important;
}
.question p {
  margin: 0 !important;
  color: var(--muted) !important;
  font: 400 13px/1.55 var(--font-display) !important;
}

/* 折叠面板 */
.accordion details {
  margin-bottom: 6px !important;
  border: 1px solid var(--line) !important;
  background: var(--surface-strong) !important;
  border-radius: var(--r) !important;
  box-shadow: var(--shadow-sm) !important;
  overflow: hidden;
}
.accordion summary {
  padding: 14px 18px !important;
  cursor: pointer !important;
  font: 600 15px/1.3 var(--font-display) !important;
  list-style: none !important;
  color: var(--ink) !important;
}
.accordion summary::-webkit-details-marker {
  display: none !important;
}
.accordion summary::before {
  content: "+" !important;
  display: inline-block !important;
  width: 18px !important;
  margin-right: 8px !important;
  color: var(--red) !important;
  font-weight: 700 !important;
  font-size: 16px !important;
}
.accordion details[open] summary::before {
  content: "\2212" !important;
}
.accordion .acc-body {
  padding: 0 18px 14px 44px !important;
  color: var(--ink-soft-2) !important;
  font-size: 15px !important;
  line-height: 1.65 !important;
  font-family: var(--font-body) !important;
}

/* 源标记 */
.note[data-source],
.question[data-source],
.accordion details[data-source] {
  position: relative !important;
  padding-left: 24px !important;
  border-left: 3px solid var(--line) !important;
  transition: border-color 0.2s var(--ease) !important;
}
.note[data-source]:hover,
.question[data-source]:hover,
.accordion details[data-source]:hover {
  border-left-color: var(--red) !important;
}
[data-source]::after {
  content: attr(data-source) !important;
  position: absolute !important;
  left: -4px !important;
  bottom: calc(100% + 4px) !important;
  padding: 3px 8px !important;
  background: var(--ink) !important;
  color: var(--white) !important;
  font: 500 11px/1.3 var(--font-display) !important;
  border-radius: var(--r-sm) !important;
  white-space: nowrap !important;
  opacity: 0 !important;
  pointer-events: none !important;
  transition: opacity 0.2s var(--ease) !important;
  z-index: 3 !important;
}
[data-source]:hover::after {
  opacity: 1 !important;
}

/* 过渡文字 */
.transition {
  margin: 24px 0 12px !important;
  color: var(--ink-soft) !important;
  font-size: 15px !important;
  line-height: 1.7 !important;
  text-align: center !important;
  font-family: var(--font-body) !important;
}

/* 源切换按钮 */
.src-toggle {
  padding: 6px 12px !important;
  border: 1px solid var(--line) !important;
  border-radius: var(--r-sm) !important;
  background: var(--bar-bg) !important;
  backdrop-filter: blur(8px) !important;
  cursor: pointer !important;
  font: 500 12px/1.2 var(--font-display) !important;
  color: var(--muted) !important;
  transition: all 0.2s var(--ease) !important;
}
.src-toggle:hover {
  border-color: var(--red) !important;
  color: var(--red) !important;
}

/* ===== 9. 第5章等特殊网格覆盖 ===== */
.quality-grid .q-item,
.find-grid .f-item,
.method-list .ml-item,
.challenge-grid .ch-item,
.innovation-grid .in-item,
.transform-grid .tr-item {
  border-radius: var(--r) !important;
  background: var(--surface-strong) !important;
  box-shadow: var(--shadow-sm) !important;
  transition: all 0.25s var(--ease) !important;
}
.quality-grid .q-item:hover,
.find-grid .f-item:hover,
.method-list .ml-item:hover,
.challenge-grid .ch-item:hover,
.innovation-grid .in-item:hover,
.transform-grid .tr-item:hover {
  border-color: var(--red) !important;
  box-shadow: var(--shadow) !important;
  transform: translateY(-2px);
}
.quality-grid .q-item h4,
.find-grid .f-item h4,
.method-list .ml-item h4,
.challenge-grid .ch-item h4,
.innovation-grid .in-item h4 {
  font-weight: 700 !important;
}
.find-grid .f-item h4 {
  color: var(--red) !important;
}
.innovation-grid .in-item h4 {
  color: var(--green) !important;
}
.innovation-grid .in-item {
  border-left: 4px solid var(--green) !important;
}
.challenge-grid .ch-item {
  border-left: 4px solid var(--red) !important;
}
.method-list .ml-item .ml-num {
  background: var(--red) !important;
}
.transform-grid .tr-item .tr-to {
  color: var(--red) !important;
}
.transform-grid .tr-item .tr-arrow {
  color: var(--gold) !important;
}

/* ===== 10. 滚动条美化 ===== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--line);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--muted);
}

/* ===== 11. 选中文本 ===== */
::selection {
  background: var(--tint-accent-strong);
  color: var(--ink);
}

/* ===== 12. 移动端适配 ===== */
@media (max-width: 880px) {
  .grid {
    grid-template-columns: 1fr !important;
  }
  .tabs {
    grid-template-columns: repeat(3, 1fr) !important;
  }
  .ch-nav {
    flex-direction: column !important;
    gap: 10px !important;
  }
  .chapter-grid {
    grid-template-columns: 1fr !important;
  }
}
@media (max-width: 520px) {
  .page {
    width: min(100% - 22px, 1180px) !important;
    padding-top: 18px !important;
  }
  .tabs {
    grid-template-columns: repeat(2, 1fr) !important;
  }
  .ch-header h1 {
    font-size: 26px !important;
  }
  .landing-hero {
    padding: 48px 20px 36px !important;
  }
  .dashboard-card {
    flex-direction: column;
    text-align: center;
    padding: 20px !important;
  }
}