/* ==========================================================================
   通义千问官方设计系统 - 点线目录 · 书前目录 (Table of Contents with Dot Leaders)
   设计风格：书前目录
   场景：千问官网
   布局：左侧标题，右侧页码，中间用点线连接，整页只有目录
   风格说明：书前目录：点线极细，页码旧式衬线
   提示词：
   风格种「书前目录」。把千问官网做成一页书前目录。布局：左为篇名，右为页码，中间点线连接，整页没有别的模块。风格：书前目录，点线极细。字体：篇名宋体，页码旧式衬线。篇名依次为千问、千问AI、千问网页版、千问办公、qwen AI，书名页眉写通义千问 / qianwen。不要图标和缩略图。
   ========================================================================== */

:root {
  /* 典籍书纸色彩体系 */
  --toc-paper-bg: #f8f6f0;       /* 象牙书页底色 */
  --toc-paper-pure: #ffffff;     /* 纯白 */
  --toc-paper-card: #f2efe9;     /* 衬页淡米灰 */
  --toc-paper-border: #dcd7cc;   /* 装帧边线 */
  --toc-paper-rule: #c8c2b4;     /* 纸张切线 */

  /* 墨色层级 */
  --toc-ink-primary: #181715;    /* 浓黑徽墨 */
  --toc-ink-prose: #2c2a26;      /* 经卷深墨 */
  --toc-ink-muted: #625f57;      /* 烟墨注释 */
  --toc-ink-faint: #8e8a80;      /* 淡墨点线与页号 */

  /* 字体系统：严格尊奉篇名宋体、页码旧式衬线、全局无衬线交互 */
  --font-songti: "Songti SC", "SimSun", "STSong", "Noto Serif SC", "Source Han Serif SC", serif;
  --font-oldstyle-serif: "Georgia", "Baskerville", "Palatino", "Times New Roman", "STSong", serif;
  --font-ui-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "SF Mono", "Fira Code", Consolas, "Courier New", monospace;

  /* 版心 */
  --container-max-width: 1200px;
  --toc-stage-width: 900px;
  --transition-smooth: all 0.25s ease;
}

/* 全局重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--toc-paper-bg);
  color: var(--toc-ink-primary);
}

body {
  font-family: var(--font-ui-sans);
  background-color: var(--toc-paper-bg);
  color: var(--toc-ink-prose);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 布局版心 */
.layout-container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ==========================================================================
   1. 顶栏：标志、七个锚点、登录、开始使用
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(248, 246, 240, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--toc-paper-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--toc-ink-primary);
}

.brand-logo-frame {
  width: 34px;
  height: 34px;
  border: 1px solid var(--toc-paper-border);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--toc-paper-pure);
}

.brand-logo {
  width: 22px;
  height: 22px;
  object-fit: contain;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-family: var(--font-songti);
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.04em;
  color: var(--toc-ink-primary);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--toc-ink-muted);
  letter-spacing: 0.1em;
}

/* 七个锚点 */
.nav-anchors {
  display: flex;
  align-items: center;
  gap: 20px;
  list-style: none;
}

.nav-link {
  font-family: var(--font-ui-sans);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--toc-ink-muted);
  text-decoration: none;
  padding: 6px 0;
  position: relative;
  transition: var(--transition-smooth);
}

.nav-link:hover, .nav-link.active {
  color: var(--toc-ink-primary);
  font-weight: 700;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--toc-ink-primary);
  transition: var(--transition-smooth);
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

/* 登录、开始使用 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-header-login {
  font-family: var(--font-ui-sans);
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--toc-ink-primary);
  text-decoration: none;
  padding: 7px 16px;
  border: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-pure);
  transition: var(--transition-smooth);
}

.btn-header-login:hover {
  background: var(--toc-paper-card);
  border-color: var(--toc-ink-primary);
}

.btn-header-primary {
  font-family: var(--font-ui-sans);
  font-size: 0.86rem;
  font-weight: 700;
  color: #ffffff;
  text-decoration: none;
  padding: 7px 20px;
  background: var(--toc-ink-primary);
  border: 1px solid var(--toc-ink-primary);
  transition: var(--transition-smooth);
}

.btn-header-primary:hover {
  background: #333333;
}

/* ==========================================================================
   2. 首屏：状态标签、标题、一句说明、一条提问框
   ========================================================================== */
.hero-section {
  padding: 56px 0 40px;
  border-bottom: 1px solid var(--toc-paper-border);
}

.hero-status-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.hero-status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  background: var(--toc-paper-card);
  border: 1px solid var(--toc-paper-border);
  color: var(--toc-ink-primary);
}

.hero-spec-tag {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--toc-ink-muted);
}

.hero-title-box {
  margin-bottom: 20px;
}

/* 唯一 H1 必须与 Title 严格一致 */
.hero-h1 {
  font-family: var(--font-songti);
  font-size: clamp(1.8rem, 3.4vw, 2.7rem);
  font-weight: 900;
  line-height: 1.3;
  color: var(--toc-ink-primary);
  letter-spacing: -0.01em;
}

.hero-desc {
  font-family: var(--font-songti);
  font-size: 1.12rem;
  line-height: 1.9;
  color: var(--toc-ink-prose);
  max-width: 960px;
  margin-bottom: 32px;
}

/* 一条提问框 */
.hero-search-box {
  max-width: 880px;
  margin-bottom: 48px;
}

.hero-search-form {
  display: flex;
  border: 1px solid var(--toc-ink-primary);
  background: var(--toc-paper-pure);
  box-shadow: 0 4px 20px rgba(24, 23, 21, 0.05);
}

.hero-search-input {
  flex: 1;
  padding: 16px 20px;
  font-family: var(--font-songti);
  font-size: 1rem;
  border: none;
  background: transparent;
  color: var(--toc-ink-primary);
  outline: none;
}

.hero-search-input::placeholder {
  color: var(--toc-ink-faint);
}

.hero-search-btn {
  padding: 0 32px;
  font-family: var(--font-ui-sans);
  font-size: 0.95rem;
  font-weight: 700;
  background: var(--toc-ink-primary);
  color: #ffffff;
  border: none;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.hero-search-btn:hover {
  background: #333333;
}

/* ==========================================================================
   ★ 核心风格：点线目录 · 书前目录核心舞台 (Table of Contents with Dot Leaders)
   场景：千问官网
   布局：左为篇名，右为页码，中间点线连接，整页没有别的模块
   风格：书前目录，点线极细
   字体：篇名宋体，页码旧式衬线
   篇名依次为：千问、千问AI、千问网页版、千问办公、qwen AI
   书名页眉写：通义千问 / qianwen
   视觉禁忌：不要图标和缩略图
   ========================================================================== */
.toc-stage-wrapper {
  max-width: var(--toc-stage-width);
  margin: 36px auto 0;
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-rule);
  padding: 60px 80px;
  box-shadow: 0 8px 30px rgba(24, 23, 21, 0.06);
  position: relative;
}

@media (max-width: 768px) {
  .toc-stage-wrapper {
    padding: 36px 24px;
  }
}

/* 书名页眉：通义千问 / qianwen（极细横线分隔，典雅对开） */
.toc-running-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--toc-paper-rule);
  padding-bottom: 16px;
  margin-bottom: 48px;
  font-family: var(--font-songti);
  font-size: 0.92rem;
  letter-spacing: 0.15em;
  color: var(--toc-ink-muted);
}

.toc-running-title {
  font-weight: 700;
  color: var(--toc-ink-primary);
}

.toc-running-sub {
  font-family: var(--font-oldstyle-serif);
  font-style: italic;
  font-size: 0.9rem;
  letter-spacing: 0.05em;
}

/* 书前目录主标题（目次） */
.toc-main-heading-block {
  text-align: center;
  margin-bottom: 56px;
}

.toc-main-title {
  font-family: var(--font-songti);
  font-size: 1.8rem;
  font-weight: 900;
  letter-spacing: 0.4em;
  color: var(--toc-ink-primary);
  text-indent: 0.4em; /* 居中字距补偿 */
}

.toc-main-subtitle {
  font-family: var(--font-oldstyle-serif);
  font-size: 0.8rem;
  letter-spacing: 0.25em;
  color: var(--toc-ink-faint);
  margin-top: 8px;
}

/* 点线目录列表：整页只有目录，无图标、无缩略图 */
.toc-entries-list {
  display: flex;
  flex-direction: column;
  gap: 32px;
  margin-bottom: 48px;
}

/* 单条目：左为篇名（宋体），右为页码（旧式衬线），中间点线连接（极细点线） */
.toc-item-row {
  display: flex;
  align-items: baseline;
  width: 100%;
  text-decoration: none;
  color: inherit;
  transition: var(--transition-smooth);
}

.toc-item-row:hover .toc-chapter-name {
  color: #8b0000; /* 典籍微赭朱红指示聚焦 */
}

.toc-item-row:hover .toc-dot-leader {
  border-bottom-color: #8b0000;
}

/* 左侧篇名：宋体，字大厚重端方 */
.toc-chapter-name {
  font-family: var(--font-songti);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--toc-ink-primary);
  white-space: nowrap;
  padding-right: 14px;
  letter-spacing: 0.05em;
  transition: var(--transition-smooth);
}

/* 中间点线：极细（1px dotted），纯粹无装饰 */
.toc-dot-leader {
  flex-grow: 1;
  border-bottom: 1px dotted var(--toc-ink-faint);
  margin: 0 4px;
  height: 0;
  transform: translateY(-4px); /* 对齐基线居中 */
  transition: var(--transition-smooth);
}

/* 右侧页码：旧式衬线体（oldstyle-nums），字格高低错落具有古雅书籍手感 */
.toc-page-num {
  font-family: var(--font-oldstyle-serif);
  font-variant-numeric: oldstyle-nums;
  font-feature-settings: "onum" 1;
  font-size: 1.22rem;
  font-weight: 600;
  color: var(--toc-ink-primary);
  white-space: nowrap;
  padding-left: 14px;
  letter-spacing: 0.05em;
}

/* 书前目录脚标说明（纯排印，绝无杂图） */
.toc-page-footer {
  border-top: 1px solid var(--toc-paper-rule);
  padding-top: 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-oldstyle-serif);
  font-size: 0.78rem;
  color: var(--toc-ink-muted);
}

/* ==========================================================================
   3. 信任：客户名和四个数字
   ========================================================================== */
.trust-section {
  padding: 48px 0;
  border-bottom: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-card);
}

.trust-clients-row {
  margin-bottom: 32px;
  text-align: center;
}

.trust-label {
  font-family: var(--font-songti);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--toc-ink-muted);
  margin-bottom: 16px;
}

.clients-list {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.client-name-item {
  font-family: var(--font-songti);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--toc-ink-primary);
  letter-spacing: 0.05em;
  padding: 6px 14px;
  border: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-pure);
}

.metrics-4-col {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.metric-card {
  padding: 24px;
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-border);
  text-align: center;
}

.metric-number {
  font-family: var(--font-oldstyle-serif);
  font-variant-numeric: oldstyle-nums;
  font-size: clamp(2rem, 3vw, 2.6rem);
  font-weight: 700;
  color: var(--toc-ink-primary);
  line-height: 1.1;
  margin-bottom: 8px;
}

.metric-label {
  font-family: var(--font-songti);
  font-size: 0.88rem;
  color: var(--toc-ink-muted);
}

/* ==========================================================================
   4. 能力：4 列 × 2 行，只有图标、标题和两行字
   ========================================================================== */
.capabilities-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
}

.section-head-bar {
  margin-bottom: 40px;
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--toc-ink-muted);
  margin-bottom: 8px;
}

.section-h2 {
  font-family: var(--font-songti);
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  font-weight: 800;
  color: var(--toc-ink-primary);
  letter-spacing: -0.01em;
}

.cap-grid-4x2 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.cap-card {
  padding: 24px;
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-border);
  display: flex;
  flex-direction: column;
  transition: var(--transition-smooth);
}

.cap-card:hover {
  border-color: var(--toc-ink-primary);
  transform: translateY(-2px);
}

.cap-icon {
  font-family: var(--font-oldstyle-serif);
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 14px;
  color: var(--toc-ink-primary);
}

.cap-title {
  font-family: var(--font-songti);
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 10px;
}

/* 只有两行字 */
.cap-desc-line1, .cap-desc-line2 {
  font-family: var(--font-songti);
  font-size: 0.88rem;
  color: var(--toc-ink-muted);
  line-height: 1.6;
}

/* ==========================================================================
   5. 目录：两组，每组 3 张卡，带状态和「试用 / 文档」
   ========================================================================== */
.catalog-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-card);
}

.catalog-group-title {
  font-family: var(--font-songti);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.catalog-group-title::before {
  content: "§";
  color: var(--toc-ink-primary);
  font-family: var(--font-oldstyle-serif);
}

.catalog-group-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

.catalog-card {
  padding: 24px;
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-border);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.catalog-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}

.catalog-card-name {
  font-family: var(--font-songti);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
}

.catalog-status-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 3px 8px;
  background: var(--toc-paper-card);
  border: 1px solid var(--toc-paper-border);
  color: var(--toc-ink-primary);
  font-weight: 600;
}

.catalog-card-body {
  font-family: var(--font-songti);
  font-size: 0.9rem;
  color: var(--toc-ink-prose);
  line-height: 1.7;
  margin-bottom: 20px;
}

.catalog-card-actions {
  display: flex;
  gap: 12px;
  border-top: 1px solid var(--toc-paper-border);
  padding-top: 14px;
}

.btn-card-trial {
  flex: 1;
  text-align: center;
  font-family: var(--font-ui-sans);
  font-size: 0.84rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--toc-ink-primary);
  text-decoration: none;
  padding: 8px 0;
  transition: var(--transition-smooth);
}

.btn-card-trial:hover {
  background: #333333;
}

.btn-card-doc {
  flex: 1;
  text-align: center;
  font-family: var(--font-ui-sans);
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--toc-ink-primary);
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-border);
  text-decoration: none;
  padding: 8px 0;
  transition: var(--transition-smooth);
}

.btn-card-doc:hover {
  background: var(--toc-paper-card);
}

/* ==========================================================================
   6. 场景：3 列 × 2 行（合理插入 1.webp-4.webp）
   ========================================================================== */
.scenarios-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
}

.scenarios-grid-3x2 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.scenario-card {
  border: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-pure);
  display: flex;
  flex-direction: column;
}

.scenario-img-box {
  width: 100%;
  height: 190px;
  overflow: hidden;
  background: var(--toc-paper-card);
  border-bottom: 1px solid var(--toc-paper-border);
}

.scenario-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.scenario-content {
  padding: 20px;
}

.scenario-title {
  font-family: var(--font-songti);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 8px;
}

.scenario-desc {
  font-family: var(--font-songti);
  font-size: 0.88rem;
  color: var(--toc-ink-prose);
  line-height: 1.7;
}

/* ==========================================================================
   7. 演示：左边任务，右边结果
   ========================================================================== */
.demo-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-card);
}

.demo-split-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  border: 1px solid var(--toc-paper-rule);
  background: var(--toc-paper-pure);
}

.demo-task-left, .demo-result-right {
  padding: 32px;
}

.demo-task-left {
  border-right: 1px solid var(--toc-paper-border);
}

.demo-pane-tag {
  font-family: var(--font-oldstyle-serif);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--toc-ink-muted);
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.demo-pane-title {
  font-family: var(--font-songti);
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 16px;
}

.demo-prompt-box {
  background: var(--toc-paper-card);
  border: 1px solid var(--toc-paper-border);
  padding: 18px;
  font-family: var(--font-songti);
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--toc-ink-primary);
  margin-bottom: 16px;
}

.demo-result-content {
  font-family: var(--font-songti);
  font-size: 0.95rem;
  line-height: 1.95;
  color: var(--toc-ink-prose);
}

/* ==========================================================================
   8. 开发者：左边卖点，右边可切换的代码
   ========================================================================== */
.dev-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
}

.dev-split-container {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 32px;
  align-items: start;
}

.dev-points-left {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.dev-point-item {
  padding: 20px;
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-border);
}

.dev-point-title {
  font-family: var(--font-songti);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 8px;
}

.dev-point-desc {
  font-family: var(--font-songti);
  font-size: 0.9rem;
  color: var(--toc-ink-prose);
  line-height: 1.7;
}

.dev-code-box-right {
  border: 1px solid var(--toc-paper-rule);
  background: #191816;
  color: #eeeeee;
}

.code-tabs-bar {
  display: flex;
  background: #23221f;
  border-bottom: 1px solid #33322f;
}

.code-tab-btn {
  padding: 10px 20px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: #a09e97;
  background: transparent;
  border: none;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.code-tab-btn.active, .code-tab-btn:hover {
  color: #ffffff;
  background: #191816;
}

.code-block-body {
  padding: 24px;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  line-height: 1.75;
  overflow-x: auto;
  color: #e2e0d8;
}

.code-keyword { color: #f07178; }
.code-string { color: #c3e88d; }
.code-func { color: #82aaff; }
.code-comment { color: #7f7c75; font-style: italic; }

/* ==========================================================================
   9. 企业：3 列 × 2 行
   ========================================================================== */
.enterprise-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-card);
}

.ent-grid-3x2 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.ent-card {
  padding: 24px;
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-border);
}

.ent-card-tag {
  font-family: var(--font-oldstyle-serif);
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--toc-ink-muted);
  margin-bottom: 8px;
}

.ent-card-title {
  font-family: var(--font-songti);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 10px;
}

.ent-card-desc {
  font-family: var(--font-songti);
  font-size: 0.88rem;
  color: var(--toc-ink-prose);
  line-height: 1.7;
}

/* ==========================================================================
   10. 下载和帮助：各 5 列
   ========================================================================== */
.downloads-help-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
}

.five-col-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.five-col-card {
  padding: 20px 16px;
  background: var(--toc-paper-pure);
  border: 1px solid var(--toc-paper-border);
  text-align: center;
}

.five-col-tag {
  font-family: var(--font-oldstyle-serif);
  font-size: 0.74rem;
  color: var(--toc-ink-muted);
  margin-bottom: 6px;
}

.five-col-title {
  font-family: var(--font-songti);
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 8px;
}

.five-col-desc {
  font-family: var(--font-songti);
  font-size: 0.82rem;
  color: var(--toc-ink-muted);
  line-height: 1.6;
}

/* ==========================================================================
   11. 问答：默认折叠，点开才看步骤
   ========================================================================== */
.faq-section {
  padding: 64px 0;
  border-bottom: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-card);
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 960px;
  margin: 0 auto;
}

.faq-details {
  border: 1px solid var(--toc-paper-border);
  background: var(--toc-paper-pure);
  transition: var(--transition-smooth);
}

.faq-details[open] {
  border-color: var(--toc-ink-primary);
}

.faq-summary {
  padding: 20px 24px;
  font-family: var(--font-songti);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-toggle-icon {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 400;
  color: var(--toc-ink-muted);
  transition: transform 0.25s ease;
}

.faq-details[open] .faq-toggle-icon {
  transform: rotate(45deg);
}

.faq-content-drawer {
  padding: 0 24px 24px;
  border-top: 1px dashed var(--toc-paper-border);
  margin-top: 4px;
}

.faq-step-line {
  font-family: var(--font-songti);
  font-size: 0.94rem;
  line-height: 1.9;
  color: var(--toc-ink-prose);
  margin-top: 12px;
}

.faq-step-line strong {
  font-family: var(--font-songti);
  color: var(--toc-ink-primary);
  font-weight: 800;
}

/* ==========================================================================
   12. 页脚：品牌说明加四列链接
   ========================================================================== */
.site-footer {
  padding: 56px 0 32px;
  background: var(--toc-paper-pure);
  border-top: 1px solid var(--toc-paper-rule);
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 40px;
}

.footer-brand-title {
  font-family: var(--font-songti);
  font-size: 1.15rem;
  font-weight: 900;
  color: var(--toc-ink-primary);
  margin-bottom: 12px;
}

.footer-brand-desc {
  font-family: var(--font-songti);
  font-size: 0.88rem;
  line-height: 1.85;
  color: var(--toc-ink-muted);
}

.footer-col-title {
  font-family: var(--font-songti);
  font-size: 0.92rem;
  font-weight: 800;
  color: var(--toc-ink-primary);
  margin-bottom: 14px;
  border-bottom: 1px solid var(--toc-paper-border);
  padding-bottom: 6px;
}

.footer-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-links-list a {
  font-family: var(--font-songti);
  font-size: 0.85rem;
  color: var(--toc-ink-muted);
  text-decoration: none;
  transition: var(--transition-smooth);
}

.footer-links-list a:hover {
  color: var(--toc-ink-primary);
  text-decoration: underline;
}

.footer-bottom-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--toc-paper-border);
  padding-top: 24px;
  font-family: var(--font-oldstyle-serif);
  font-size: 0.78rem;
  color: var(--toc-ink-muted);
}

/* 响应式调整 */
@media (max-width: 1024px) {
  .cap-grid-4x2 { grid-template-columns: repeat(2, 1fr); }
  .catalog-group-grid { grid-template-columns: repeat(2, 1fr); }
  .scenarios-grid-3x2 { grid-template-columns: repeat(2, 1fr); }
  .ent-grid-3x2 { grid-template-columns: repeat(2, 1fr); }
  .five-col-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-top-grid { grid-template-columns: 1fr 1fr; }
  .metrics-4-col { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-anchors { display: none; }
  .demo-split-container { grid-template-columns: 1fr; }
  .dev-split-container { grid-template-columns: 1fr; }
  .catalog-group-grid { grid-template-columns: 1fr; }
  .scenarios-grid-3x2 { grid-template-columns: 1fr; }
  .ent-grid-3x2 { grid-template-columns: 1fr; }
  .five-col-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-top-grid { grid-template-columns: 1fr; }
}