/* ============================================================
   51大赛 · 整站样式表
   开发者文档风：冷白背景 / 蓝绿主色 / 等宽编号
   ============================================================ */

/* ------------------------------------------------------------
   1. Base — 变量、reset、全局字体与颜色
   ------------------------------------------------------------ */
:root {
  --bg: #f6f8f8;
  --surface: #ffffff;
  --text: #1e2b2b;
  --text-secondary: #4a5a5a;
  --primary: #0a7d72;
  --primary-dark: #075c54;
  --accent: #2fb8a5;
  --info: #1c7ed6;
  --success: #2f9e44;
  --warning: #e8590c;
  --border: #d9e2e2;
  --border-light: #e8eeee;
  --radius: 6px;
  --radius-sm: 4px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", Consolas, "Courier New", monospace;
  --header-h: 64px;
  --container-w: 1200px;
  --sidebar-w: 240px;
  --content-w: 800px;
  --gap: 24px;
  --shadow-sm: 0 1px 2px rgba(30, 43, 43, 0.06);
  --shadow-md: 0 4px 12px rgba(30, 43, 43, 0.08);
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.3;
  font-weight: 700;
  color: var(--text);
}

h1 {
  font-size: 32px;
  letter-spacing: 0;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

p {
  margin-bottom: 1em;
}

p:last-child {
  margin-bottom: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ------------------------------------------------------------
   2. Layout — 页头、页脚、整体骨架
   ------------------------------------------------------------ */

/* 页头 */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  font-size: 22px;
  font-weight: 800;
  margin: 0;
  flex-shrink: 0;
}

.brand a {
  color: var(--text);
  text-decoration: none;
  font-family: var(--font-mono);
  letter-spacing: 0;
}

.brand a:hover {
  color: var(--primary);
  text-decoration: none;
}

/* 主导航 */
.site-nav {
  margin-left: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-list li {
  margin: 0;
}

.nav-list a {
  display: inline-block;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: color 0.2s ease, background-color 0.2s ease;
}

.nav-list a:hover {
  color: var(--primary);
  background: rgba(10, 125, 114, 0.06);
  text-decoration: none;
}

.nav-list a.is-current {
  color: var(--primary);
  font-weight: 700;
  background: rgba(10, 125, 114, 0.08);
}

/* 移动导航按钮（桌面隐藏） */
.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 44px;
  height: 44px;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.nav-toggle-icon {
  position: relative;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: background-color 0.2s ease;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.2s ease;
}

.nav-toggle-icon::before {
  top: -6px;
}

.nav-toggle-icon::after {
  top: 6px;
}

/* 页脚 */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-brand {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0;
  flex-shrink: 0;
}

.footer-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-nav a {
  font-size: 13px;
  color: var(--text-secondary);
}

.footer-nav a:hover {
  color: var(--primary);
  text-decoration: none;
}

.footer-copy {
  font-size: 13px;
  color: var(--text-secondary);
  margin: 0;
  flex-shrink: 0;
}

/* ------------------------------------------------------------
   3. 页面布局骨架 — 侧栏 + 主内容
   ------------------------------------------------------------ */

/* 通用侧栏布局 */
.layout-shell,
.page-layout {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 32px 24px 48px;
  width: 100%;
  flex: 1;
}

/* 侧栏在左的布局：aside 在前，main 在后 */
.sidebar-left {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  gap: var(--gap);
  align-items: start;
}

/* 侧栏 */
.sidebar {
  position: sticky;
  top: calc(var(--header-h) + 24px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  max-height: calc(100vh - var(--header-h) - 48px);
  overflow-y: auto;
}

.sidebar-inner {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.sidebar-label,
.sidebar-title {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin: 0 0 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-light);
}

.sidebar-label + .sidebar-label {
  margin-top: 12px;
}

.sidebar-toc,
.sidebar-list,
.sidebar-nav,
.sidebar ul {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar-toc a,
.sidebar-list a,
.sidebar-nav a {
  display: block;
  padding: 6px 10px;
  font-size: 14px;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.sidebar-toc a:hover,
.sidebar-list a:hover,
.sidebar-nav a:hover {
  color: var(--primary);
  background: rgba(10, 125, 114, 0.05);
  text-decoration: none;
  border-left-color: var(--accent);
}

.sidebar-toc a.is-current,
.sidebar-list a.is-current,
.sidebar-nav a.is-current {
  color: var(--primary);
  font-weight: 600;
  background: rgba(10, 125, 114, 0.06);
  border-left-color: var(--primary);
}

/* 时间归档入口（首页与动态页侧栏） */
.sidebar-archive {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sidebar-archive a {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--text-secondary);
  background: var(--bg);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.sidebar-archive a:hover {
  color: var(--primary);
  border-color: var(--primary);
  background: rgba(10, 125, 114, 0.04);
  text-decoration: none;
}

/* 侧栏合作引导 */
.sidebar-guide {
  margin-top: 12px;
  padding: 14px;
  background: var(--bg);
  border-radius: var(--radius);
  border: 1px solid var(--border-light);
}

.sidebar-guide p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.sidebar-guide a {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
}

/* 主内容区 */
.site-main {
  min-width: 0;
  width: 100%;
}

.home-main {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.inner-main {
  display: flex;
  flex-direction: column;
  gap: 0;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-light);
}

.breadcrumb a {
  color: var(--text-secondary);
}

.breadcrumb a:hover {
  color: var(--primary);
  text-decoration: none;
}

.breadcrumb-sep {
  color: var(--border);
  font-family: var(--font-mono);
}

.breadcrumb-current {
  color: var(--text);
  font-weight: 600;
}

/* 页面标题区 */
.page-header {
  margin-bottom: 32px;
}

.page-title {
  font-size: 32px;
  line-height: 1.3;
  margin-bottom: 12px;
}

.page-description {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 720px;
  margin-bottom: 0;
}

.page-intro {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 720px;
  margin-bottom: 32px;
}

/* ------------------------------------------------------------
   4. 通用组件 — 卡片、列表、按钮、表格、FAQ
   ------------------------------------------------------------ */

/* 内容区块通用间距 */
.content-section,
.content-block,
.faq-section,
.guide-section {
  margin-bottom: 48px;
}

.content-section h2,
.content-block h2,
.faq-section h2,
.guide-section h2 {
  font-size: 24px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-light);
  position: relative;
}

.content-section h2::after,
.content-block h2::after,
.faq-section h2::after,
.guide-section h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 48px;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
}

.section-lead {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 20px;
  max-width: 720px;
}

/* 服务卡片（首页预览与内页通用） */
.service-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.service-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
  transform: translateY(-2px);
}

.service-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.service-card h3 {
  padding: 16px 16px 8px;
  font-size: 17px;
}

.service-card p {
  padding: 0 16px;
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.service-card a {
  display: inline-block;
  margin: 0 16px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  align-self: flex-start;
}

.service-card a:hover {
  text-decoration: underline;
}

/* 首页服务预览网格 */
.services-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

/* 内页服务卡片列表 */
.service-card-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

/* 内页服务卡片样式 */
.service-card-list .service-card {
  flex-direction: row;
  align-items: stretch;
}

.service-media {
  flex: 0 0 160px;
  min-height: 160px;
  background: var(--bg);
}

.service-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.service-body {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
  min-width: 0;
}

.service-body h3 {
  padding: 0;
  font-size: 17px;
}

.service-body p {
  padding: 0;
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

.service-body .service-scene {
  margin-top: auto;
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--bg);
  border-left: 3px solid var(--primary);
  padding: 8px 10px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* 场景说明块 */
.scenario-grid,
.scenario-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.scenario-block,
.scenario-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.scenario-block h3,
.scenario-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
  color: var(--primary);
}

.scenario-block p,
.scenario-item p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 结论要点卡片 */
.conclusion-grid,
.point-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.conclusion-item,
.point-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  position: relative;
}

.conclusion-item h3,
.point-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
  color: var(--primary);
}

.conclusion-item p,
.point-card p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 方法论步骤（首页） */
.method-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  counter-reset: method;
}

.method-step {
  display: flex;
  gap: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  align-items: flex-start;
}

.method-step .step-number {
  flex: 0 0 36px;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-sm);
}

.method-step .step-content h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.method-step .step-content p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 方法论步骤（内页 approach） */
.method-item {
  display: flex;
  gap: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  align-items: flex-start;
  margin-bottom: 12px;
}

.method-item .method-step {
  flex: 0 0 36px;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  border: 0;
  padding: 0;
}

.method-body h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.method-body p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 过程卡片 */
.process-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.process-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  border-top: 3px solid var(--primary);
}

.process-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
  color: var(--primary);
}

.process-card p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 验收标准列表 */
.result-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.result-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.result-mark,
.result-marker {
  flex: 0 0 24px;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--success);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  border-radius: 50%;
  font-family: var(--font-mono);
}

.result-marker {
  background: var(--primary);
}

.result-list li p {
  font-size: 15px;
  margin: 0;
  line-height: 1.6;
}

/* 时间线（首页横向） */
.timeline-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  position: relative;
}

.timeline-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  position: relative;
  text-align: left;
}

.timeline-node {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 12px;
}

.timeline-content h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.timeline-content p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 流程总览（内页 process，横向五步） */
.process-overview {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 12px;
  margin-bottom: 32px;
}

.process-step {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  text-align: center;
}

.process-step .step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 8px;
}

.process-step h3 {
  font-size: 15px;
  margin-bottom: 6px;
}

.process-step p {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 0;
  line-height: 1.5;
}

/* 检查清单 */
.check-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.check-list li {
  position: relative;
  padding-left: 28px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--success);
  font-weight: 700;
  font-family: var(--font-mono);
}

/* 步骤列表（guide 页） */
.prepare-list,
.execute-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.prepare-list li,
.execute-list li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  position: relative;
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.prepare-list li::before,
.execute-list li::before {
  content: counter(step);
  counter-increment: step;
  flex: 0 0 28px;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  border-radius: 50%;
}

.prepare-list {
  counter-reset: step;
}

.execute-list {
  counter-reset: step;
}

.prepare-list li h3,
.execute-list li h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.prepare-list li p,
.execute-list li p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 验收清单（guide 页） */
.acceptance-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.acceptance-list li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  border-left: 3px solid var(--success);
}

.acceptance-list h3 {
  font-size: 16px;
  margin-bottom: 6px;
  color: var(--primary);
}

.acceptance-list p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 目标列表（guide 页） */
.goal-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.goal-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  border-top: 3px solid var(--info);
}

.goal-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
  color: var(--info);
}

.goal-item p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* 按钮 */
.hero-btn,
.cta-btn,
.archive-btn,
.error-btn,
.guide-cta a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 24px;
  background: var(--primary);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid var(--primary);
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
  text-decoration: none;
}

.hero-btn:hover,
.cta-btn:hover,
.archive-btn:hover,
.error-btn:hover,
.guide-cta a:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
  color: #fff;
  text-decoration: none;
  transform: translateY(-1px);
}

.hero-btn.secondary,
.archive-btn {
  background: var(--surface);
  color: var(--primary);
  border-color: var(--primary);
}

.hero-btn.secondary:hover,
.archive-btn:hover {
  background: rgba(10, 125, 114, 0.06);
  color: var(--primary-dark);
  border-color: var(--primary-dark);
}

/* 合作入口 */
.cta {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  margin-bottom: 48px;
}

.cta-content {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.cta-content h2 {
  font-size: 22px;
  margin: 0;
  border: 0;
  padding: 0;
}

.cta-content h2::after {
  display: none;
}

.cta-content p {
  font-size: 15px;
  color: var(--text-secondary);
  margin: 0;
}

.cta-content p a {
  font-weight: 600;
}

.cta-btn {
  align-self: flex-start;
  margin-top: 8px;
}

/* 动态列表 */
.updates-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.update-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  display: flex;
  gap: 16px;
  align-items: flex-start;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.update-item:hover {
  box-shadow: var(--shadow-sm);
  border-color: var(--accent);
}

.update-date {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--bg);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 4px 8px;
  white-space: nowrap;
}

.update-item p {
  font-size: 15px;
  margin: 0;
  line-height: 1.6;
}

.more-link {
  display: inline-block;
  margin-top: 16px;
  font-size: 14px;
  font-weight: 600;
}

/* 动态页的更新列表 */
.update-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.update-list .update-item {
  display: block;
  padding: 20px;
}

.update-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}

.update-meta time {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-secondary);
}

.update-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(10, 125, 114, 0.08);
  border-radius: var(--radius-sm);
  padding: 2px 8px;
}

.update-item h3 {
  font-size: 17px;
  margin-bottom: 6px;
}

.update-item h3 a {
  color: var(--text);
}

.update-item h3 a:hover {
  color: var(--primary);
  text-decoration: none;
}

.update-item > p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.update-item > a {
  font-size: 14px;
  font-weight: 600;
}

/* FAQ 折叠面板 */
.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-item summary {
  padding: 16px 20px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 44px;
  transition: color 0.2s ease;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--primary);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item summary:hover {
  color: var(--primary);
}

.faq-item[open] summary {
  border-bottom: 1px solid var(--border-light);
  color: var(--primary);
}

.faq-answer {
  padding: 16px 20px;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.faq-answer p {
  margin-bottom: 0;
}

.faq-answer a {
  font-weight: 600;
}

/* 相关链接 */
.related-links {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.related-links-label {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.related-links-item {
  display: inline-block;
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-secondary);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.related-links-item:hover {
  color: var(--primary);
  border-color: var(--primary);
  text-decoration: none;
}

/* related-links（approach 页变体） */
.related-links .related-title {
  font-size: 18px;
  margin: 0 16px 0 0;
}

.related-list {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.related-list a {
  display: inline-block;
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-secondary);
}

.related-list a:hover {
  color: var(--primary);
  border-color: var(--primary);
  text-decoration: none;
}

/* 表格 */
.deliverable-table-wrap {
  overflow-x: auto;
  margin: 16px 0;
}

.deliverable-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.deliverable-table th,
.deliverable-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-light);
  vertical-align: top;
}

.deliverable-table th {
  background: var(--bg);
  font-weight: 700;
  font-family: var(--font-mono);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-secondary);
}

.deliverable-table tr:last-child td {
  border-bottom: 0;
}

.deliverable-table tbody tr:hover {
  background: rgba(10, 125, 114, 0.02);
}

/* 备注列表 */
.note-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.note-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.note-list li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--primary);
  font-weight: 700;
}

/* 图文容器 */
.section-figure,
.media-figure,
.content-figure {
  margin: 24px 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.section-figure img,
.media-figure img,
.content-figure img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

.section-figure figcaption,
.media-figure figcaption,
.content-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--bg);
  border-top: 1px solid var(--border-light);
}

/* 归档区块 */
.archive-block {
  margin-bottom: 40px;
}

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

.archive-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.archive-card h3 {
  font-size: 17px;
  color: var(--primary);
}

.archive-card p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 0;
}

.archive-card a {
  font-size: 14px;
  font-weight: 600;
  margin-top: auto;
  padding-top: 8px;
}

.archive-actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.archive-btn {
  width: 100%;
  justify-content: flex-start;
}

/* guide 页 hero 图 */
.guide-hero {
  margin-bottom: 32px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

.guide-hero img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

/* guide 页 CTA */
.guide-cta {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.guide-cta p {
  font-size: 15px;
  color: var(--text-secondary);
  margin: 0;
}

.guide-cta a {
  flex-shrink: 0;
}

/* FAQ 页头部配图 */
.page-header-media {
  margin-top: 16px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

.page-header-media img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.page-header-media figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--bg);
  border-top: 1px solid var(--border-light);
}

/* FAQ 相关链接区 */
.faq-related-links {
  margin-top: 32px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.faq-related-links p {
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0;
}

.faq-related-links a {
  display: inline-block;
  padding: 4px 10px;
  background: var(--bg);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-secondary);
}

.faq-related-links a:hover {
  color: var(--primary);
  border-color: var(--primary);
  text-decoration: none;
}

/* ------------------------------------------------------------
   5. 首页专属模块
   ------------------------------------------------------------ */

/* Hero 区 */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  margin-bottom: 48px;
}

.hero-text {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.hero-text h1 {
  font-size: 32px;
  line-height: 1.3;
  margin: 0;
}

.hero-slogan {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--primary);
  font-weight: 700;
  margin: 0;
}

.hero-description {
  font-size: 15px;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 12px;
  margin-top: 8px;
}

.hero-figure {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg);
}

.hero-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

/* 首页结论区 */
.conclusion {
  margin-bottom: 48px;
}

.conclusion h2,
.method h2,
.process h2,
.result h2,
.services-preview h2,
.scenarios h2,
.timeline h2,
.updates h2,
.faq-preview h2 {
  font-size: 24px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-light);
  position: relative;
}

.conclusion h2::after,
.method h2::after,
.process h2::after,
.result h2::after,
.services-preview h2::after,
.scenarios h2::after,
.timeline h2::after,
.updates h2::after,
.faq-preview h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 48px;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
}

.conclusion-lead {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 720px;
  margin-bottom: 20px;
}

/* 首页服务预览 */
.services-preview {
  margin-bottom: 48px;
}

.services-preview > p {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.services-preview > p a {
  font-weight: 600;
}

/* 首页场景 */
.scenarios {
  margin-bottom: 48px;
}

.scenarios > p {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

/* 首页时间线 */
.timeline {
  margin-bottom: 48px;
}

.timeline > p {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.timeline > p a {
  font-weight: 600;
}

/* 首页动态 */
.updates {
  margin-bottom: 48px;
}

/* 首页 FAQ 预览 */
.faq-preview {
  margin-bottom: 48px;
}

/* ------------------------------------------------------------
   6. 404 页面
   ------------------------------------------------------------ */

.error-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 48px 24px;
}

.error-content {
  text-align: center;
  max-width: 520px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 48px 40px;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 64px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
  margin-bottom: 16px;
}

.error-content h1 {
  font-size: 24px;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.error-action {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.error-btn {
  display: inline-flex;
}

/* ------------------------------------------------------------
   7. 响应式 — 768px 断点
   ------------------------------------------------------------ */

@media (max-width: 768px) {
  /* 页头 */
  .header-inner {
    padding: 0 16px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    margin: 0;
    z-index: 99;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 12px 16px;
    gap: 2px;
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-list li {
    margin: 0;
  }

  .nav-list a {
    display: block;
    padding: 12px 16px;
    font-size: 16px;
    border-radius: var(--radius-sm);
  }

  /* 布局：侧栏折叠到主内容之后 */
  .sidebar-left {
    display: flex;
    flex-direction: column;
  }

  .sidebar {
    position: static;
    max-height: none;
    overflow: visible;
    order: 2;
    margin-top: 24px;
    order: 2;
  }

  .sidebar-left .site-main,
  .sidebar-left .inner-main,
  .sidebar-left .home-main {
    order: 1;
  }

  /* 主内容 */
  .layout-shell,
  .page-layout {
    padding: 24px 16px 40px;
  }

  .page-title {
    font-size: 26px;
  }

  h1 {
    font-size: 26px;
  }

  h2 {
    font-size: 21px;
  }

  /* 网格降列 */
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .service-card-list {
    grid-template-columns: 1fr;
  }

  .service-card-list .service-card {
    flex-direction: column;
  }

  .service-media {
    flex: none;
    width: 100%;
    height: 160px;
  }

  .scenario-grid,
  .scenario-list,
  .conclusion-grid,
  .point-grid,
  .process-grid,
  .goal-list {
    grid-template-columns: 1fr;
  }

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

  .process-overview {
    grid-template-columns: 1fr;
  }

  .acceptance-list {
    grid-template-columns: 1fr;
  }

  .archive-grid {
    grid-template-columns: 1fr;
  }

  /* Hero */
  .hero {
    grid-template-columns: 1fr;
    padding: 24px;
    gap: 20px;
  }

  .hero-figure img {
    height: 200px;
  }

  .hero-actions {
    flex-direction: column;
  }

  .hero-btn {
    width: 100%;
  }

  /* 页脚 */
  .footer-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 8px;
    padding: 20px 16px;
  }

  .footer-nav {
    justify-content: center;
    gap: 12px;
  }

  .footer-copy {
    font-size: 12px;
  }

  /* 引导 CTA */
  .guide-cta {
    flex-direction: column;
    align-items: flex-start;
  }

  .guide-cta a {
    width: 100%;
  }

  /* 表格 */
  .deliverable-table {
    min-width: 480px;
  }

  /* 相关链接 */
  .related-links {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .faq-related-links {
    flex-direction: column;
    align-items: flex-start;
  }

  .faq-related-links p {
    margin-bottom: 8px;
  }

  /* 面包屑 */
  .breadcrumb {
    margin-bottom: 16px;
    font-size: 13px;
  }

  /* 验证标准列表 */
  .result-list li {
    padding: 14px 16px;
  }
}

/* ------------------------------------------------------------
   8. 小屏补充 — 480px
   ------------------------------------------------------------ */

@media (max-width: 480px) {
  .services-grid {
    grid-template-columns: 1fr;
  }

  .timeline-list {
    grid-template-columns: 1fr;
  }

  .header-inner {
    gap: 12px;
  }

  .brand {
    font-size: 18px;
  }

  .nav-list a {
    padding: 14px 12px;
  }

  .hero {
    padding: 20px 16px;
  }

  .cta {
    padding: 24px 20px;
  }

  .cta-btn {
    width: 100%;
  }

  .footer-nav {
    flex-direction: column;
    gap: 6px;
  }

  .footer-nav a {
    display: block;
    padding: 4px 0;
  }

  .error-content {
    padding: 32px 20px;
  }

  .error-code {
    font-size: 48px;
  }
}

/* 程序验收反馈：移动端正文优先 */
@media (max-width: 768px) {
  .site-main :is(.page-content, .main-content, .content-main) {
    order: 1;
  }

  .site-main :is(aside, .sidebar) {
    order: 2;
  }
}