/* ==========================================================================
   51吃瓜导航 · 整站样式表
   版本：1.0
   说明：本文件为全站统一样式，覆盖首页、内页、侧栏、导航、页脚等全部组件。
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Base 基础层
   变量、重置、全局字体与颜色
   -------------------------------------------------------------------------- */
:root {
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-text-secondary: #475569;
  --color-text-muted: #64748b;
  --color-heading: #0f172a;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-accent: #f59e0b;
  --color-accent-light: #fef3c7;
  --color-border: #e2e8f0;
  --color-border-dark: #cbd5e1;
  --color-footer-bg: #0f172a;
  --color-footer-text: #cbd5e1;
  --color-footer-heading: #f1f5f9;
  --color-ok-bg: #ecfdf5;
  --color-ok-border: #a7f3d0;
  --color-ok-text: #065f46;
  --color-no-bg: #fef2f2;
  --color-no-border: #fecaca;
  --color-no-text: #991b1b;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
  --container-width: 1180px;
  --header-height: 64px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
}

*,
*::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: 15px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

ul,
ol {
  list-style: none;
}

button {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

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

/* --------------------------------------------------------------------------
   2. Layout 布局骨架
   全站统一：页头、容器、页脚
   -------------------------------------------------------------------------- */

/* 全站容器 */
.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.site-main {
  flex: 1 0 auto;
}

.site-header {
  background-color: var(--color-heading);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.brand {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-shrink: 0;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 0;
}

.brand-slogan {
  font-size: 13px;
  color: #94a3b8;
  font-weight: 400;
}

.main-nav {
  display: flex;
  align-items: center;
}

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

.nav-link {
  display: inline-block;
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 500;
  color: #cbd5e1;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-link:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.08);
}

.nav-link.is-current {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.12);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border-radius: var(--radius-sm);
  background: transparent;
  transition: background-color var(--transition-fast);
}

.nav-toggle:hover {
  background-color: rgba(255, 255, 255, 0.08);
}

.toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: #f1f5f9;
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* 页脚 */
.site-footer {
  background-color: var(--color-footer-bg);
  color: var(--color-footer-text);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px 32px;
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 40px;
}

.footer-brand h2 {
  font-size: 18px;
  color: var(--color-footer-heading);
  margin-bottom: 8px;
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.6;
  color: #94a3b8;
  margin-bottom: 6px;
}

.footer-nav h3 {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-footer-heading);
  margin-bottom: 12px;
}

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

.footer-nav a {
  font-size: 14px;
  color: #94a3b8;
  transition: color var(--transition-fast);
}

.footer-nav a:hover {
  color: #ffffff;
}

.footer-boundary h3 {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-footer-heading);
  margin-bottom: 12px;
}

.footer-boundary p {
  font-size: 13px;
  line-height: 1.6;
  color: #94a3b8;
  margin-bottom: 6px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 16px 24px;
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: #64748b;
}

/* 面包屑（内页） */
.breadcrumb {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 16px 24px 0;
  font-size: 13px;
  color: var(--color-text-muted);
}

.breadcrumb a {
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.breadcrumb a:hover {
  color: var(--color-primary);
}

.breadcrumb-sep {
  margin: 0 8px;
  color: var(--color-border-dark);
}

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 500;
}

/* 面包屑导航（顶部独立面包屑，用于 service / about） */
.breadcrumb-nav {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 16px 24px 0;
}

.breadcrumb-list {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--color-text-muted);
}

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

.breadcrumb-list a:hover {
  color: var(--color-primary);
}

.breadcrumb-list li + li::before {
  content: "/";
  color: var(--color-border-dark);
}

/* --------------------------------------------------------------------------
   3. Components 通用组件
   按钮、卡片、表格、提示块、相关链接等
   -------------------------------------------------------------------------- */

/* 按钮 */
.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 24px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), color var(--transition-fast),
    border-color var(--transition-fast);
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff;
  border: 1px solid var(--color-primary);
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #ffffff;
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border-dark);
}

.btn-secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background-color: var(--color-primary-light);
}

.btn-text {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  padding: 8px 0;
  min-height: 44px;
  transition: color var(--transition-fast);
}

.btn-text:hover {
  color: var(--color-primary-dark);
}

/* 卡片通用 */
.card-item,
.service-card,
.guide-card,
.entry-card,
.related-card,
.link-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: box-shadow var(--transition-base), border-color var(--transition-base),
    transform var(--transition-base);
}

.card-item:hover,
.service-card:hover,
.guide-card:hover,
.entry-card:hover,
.related-card:hover,
.link-card:hover {
  border-color: var(--color-border-dark);
  box-shadow: var(--shadow-md);
}

.card-item h3,
.service-card h3,
.guide-card h3,
.entry-card h3,
.related-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.card-item p,
.service-card p,
.guide-card p,
.entry-card p,
.related-card p,
.link-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: 12px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  min-height: 44px;
  padding-top: 8px;
  padding-bottom: 8px;
  transition: color var(--transition-fast);
}

.card-link:hover {
  color: var(--color-primary-dark);
}

.card-link::after {
  content: "→";
  font-size: 14px;
}

/* 表格 */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
}

.capability-table,
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  min-width: 560px;
}

.capability-table thead th,
.data-table thead th {
  background-color: var(--color-bg);
  color: var(--color-heading);
  font-weight: 600;
  text-align: left;
  padding: 14px 16px;
  border-bottom: 1px solid var(--color-border);
  font-family: var(--font-sans);
}

.capability-table tbody td,
.data-table tbody td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  vertical-align: top;
  line-height: 1.6;
}

.capability-table tbody tr:last-child td,
.data-table tbody tr:last-child td {
  border-bottom: none;
}

.capability-table tbody tr:hover,
.data-table tbody tr:hover {
  background-color: var(--color-bg);
}

/* 内联提示块 */
.boundary-block,
.boundary-note {
  border-left: 4px solid var(--color-accent);
  background-color: var(--color-accent-light);
  padding: 16px 20px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 14px;
  color: var(--color-text-secondary);
}

.boundary-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.boundary-list li {
  display: flex;
  gap: 8px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

.boundary-list li::before {
  content: "•";
  color: var(--color-accent);
  font-weight: 700;
  flex-shrink: 0;
}

.boundary-list strong {
  font-weight: 600;
  color: var(--color-heading);
}

/* 相关链接 */
.related-links {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 16px;
  border-top: 1px solid var(--color-border);
}

.related-links-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-heading);
}

.related-links-item {
  font-size: 14px;
  color: var(--color-primary);
  padding: 6px 0;
  transition: color var(--transition-fast);
}

.related-links-item:hover {
  color: var(--color-primary-dark);
}

.related-links-item + .related-links-item::before {
  content: "·";
  margin-right: 16px;
  color: var(--color-border-dark);
}

/* 步骤通用 */
.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 14px;
  font-weight: 700;
  font-family: var(--font-mono);
  flex-shrink: 0;
}

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

.check-list li {
  display: flex;
  gap: 8px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

.check-list li::before {
  content: "☐";
  color: var(--color-primary);
  font-family: var(--font-mono);
  flex-shrink: 0;
}

/* 输出说明 */
.step-output {
  margin-top: 12px;
  font-size: 14px;
  color: var(--color-text-secondary);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  padding: 12px 16px;
  border-radius: var(--radius-md);
}

.step-output strong {
  color: var(--color-heading);
  font-weight: 600;
}

/* 图片容器 */
.content-media,
.content-figure,
.brief-figure,
.brief-media,
.faq-intro-media,
.hero-figure {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background-color: var(--color-border);
}

.content-media img,
.content-figure img,
.brief-figure img,
.brief-media img,
.faq-intro-media img,
.hero-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.content-media figcaption,
.content-figure figcaption,
.brief-figure figcaption,
.faq-intro-media figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 8px 16px;
  background-color: rgba(15, 23, 42, 0.75);
  color: #f1f5f9;
  font-size: 13px;
  line-height: 1.5;
  backdrop-filter: blur(4px);
}

/* --------------------------------------------------------------------------
   4. Pages 页面级样式
   首页与各内页
   -------------------------------------------------------------------------- */

/* ---------- 4.1 首页 ---------- */
.home-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Hero 场景选择首屏 */
.hero {
  padding: 48px 0 32px;
}

.hero-container {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-title {
  font-size: 34px;
  line-height: 1.25;
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: 0;
}

.hero-lead {
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-secondary);
  max-width: 520px;
}

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

.hero-figure {
  aspect-ratio: 4 / 3;
}

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

.content-media-primary {
  margin-top: 32px;
  aspect-ratio: 21 / 9;
  max-height: 320px;
}

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

/* 区块通用头 */
.section-header {
  margin-bottom: 24px;
}

.section-header h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: 8px;
}

.section-header p {
  font-size: 15px;
  color: var(--color-text-secondary);
  max-width: 640px;
}

/* 服务能力总览 */
.service-overview,
.process-preview,
.guide-preview,
.faq-entry {
  padding: 40px 0;
}

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

.service-card {
  padding: 24px;
}

/* 合作流程预览 */
.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.step-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.step-item .step-number {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
}

.step-item h3 {
  font-size: 16px;
  font-weight: 600;
}

.step-item p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.section-footer {
  margin-top: 24px;
  text-align: right;
}

/* 线索使用提示 */
.guide-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

/* FAQ 入口 */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 860px;
}

.faq-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.faq-item h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.faq-item p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 4px;
}

/* ---------- 4.2 内页通用骨架 ---------- */
.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px 40px;
  width: 100%;
}

.page-header {
  padding: 24px 0 8px;
}

.page-title {
  font-size: 30px;
  font-weight: 700;
  color: var(--color-heading);
  line-height: 1.25;
}

/* 页面简介区 */
.page-brief {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  padding: 24px 0;
}

.brief-desc,
.brief-content p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.brief-figure,
.brief-media {
  aspect-ratio: 16 / 9;
  max-height: 240px;
}

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

/* 侧栏布局 */
.page-layout {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px 40px;
  width: 100%;
}

.sidebar-left {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 32px;
  align-items: start;
}

.sidebar {
  position: sticky;
  top: calc(var(--header-height) + 16px);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.sidebar-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
}

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

.sidebar-nav a {
  display: block;
  padding: 10px 12px;
  font-size: 14px;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.sidebar-nav a:hover {
  background-color: var(--color-bg);
  color: var(--color-primary);
}

.sidebar-nav a.is-current {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 600;
}

/* 侧栏分组（guide 页） */
.sidebar-group {
  margin-bottom: 8px;
}

.sidebar-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 10px 12px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-heading);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
}

.sidebar-toggle:hover {
  background-color: var(--color-bg);
}

.sidebar-toggle::after {
  content: "⌄";
  font-size: 16px;
  color: var(--color-text-muted);
  transition: transform var(--transition-fast);
}

.sidebar-toggle[aria-expanded="true"]::after {
  transform: rotate(180deg);
}

.sidebar-links {
  display: none;
  padding-left: 8px;
}

.sidebar-links.is-open {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

/* 内容区块 */
.content-section {
  padding: 32px 0;
  border-bottom: 1px solid var(--color-border);
}

.content-section:last-of-type {
  border-bottom: none;
}

.content-section h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

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

/* 卡片网格 */
.card-grid {
  display: grid;
  gap: 20px;
}

.card-grid.four-cols {
  grid-template-columns: repeat(2, 1fr);
}

.card-item {
  padding: 20px;
}

.card-item h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.card-item p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* 服务边界 */
.boundary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 16px;
}

.boundary-ok,
.boundary-no {
  padding: 20px;
  border-radius: var(--radius-lg);
  border: 1px solid;
}

.boundary-ok {
  background-color: var(--color-ok-bg);
  border-color: var(--color-ok-border);
}

.boundary-no {
  background-color: var(--color-no-bg);
  border-color: var(--color-no-border);
}

.boundary-ok h3,
.boundary-no h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
}

.boundary-ok h3 {
  color: var(--color-ok-text);
}

.boundary-no h3 {
  color: var(--color-no-text);
}

.boundary-ok ul,
.boundary-no ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.boundary-ok li,
.boundary-no li {
  font-size: 14px;
  line-height: 1.6;
  padding-left: 16px;
  position: relative;
}

.boundary-ok li::before,
.boundary-no li::before {
  position: absolute;
  left: 0;
  font-family: var(--font-mono);
}

.boundary-ok li::before {
  content: "✓";
  color: var(--color-ok-text);
}

.boundary-no li::before {
  content: "✕";
  color: var(--color-no-text);
}

.boundary-note {
  margin-top: 16px;
}

/* 联系入口卡片 */
.contact-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.link-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 120px;
}

.link-card span {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
}

/* 服务对象卡片 */
.service-audience .card-grid.four-cols {
  grid-template-columns: repeat(2, 1fr);
}

/* 服务处理步骤 */
.process-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.process-list li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.process-list h3 {
  font-size: 16px;
  font-weight: 600;
}

.process-list p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* 内容图（service 页） */
.content-figure {
  margin: 24px 0;
  aspect-ratio: 16 / 7;
  max-height: 280px;
}

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

/* ---------- 4.3 指南页 ---------- */
.page-brief {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  padding: 24px 0;
}

.step-block {
  padding: 24px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
}

.step-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.step-head .step-number {
  background-color: var(--color-primary);
}

.step-head h3 {
  font-size: 18px;
  font-weight: 600;
}

.step-block > p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

/* 相关入口 */
.related-entry {
  padding: 32px 0;
}

.related-entry h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 20px;
}

.entry-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.entry-card {
  padding: 24px;
}

.entry-card a {
  display: inline-block;
  margin-top: 12px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
}

/* ---------- 4.4 合作流程页 ---------- */
.page-brief {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  padding: 24px 0;
}

.brief-content p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.brief-media {
  aspect-ratio: 16 / 9;
  max-height: 240px;
}

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

.step-nav-section {
  padding: 24px 0;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 20px;
}

.step-nav {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.step-nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
  min-height: 44px;
}

.step-nav-item:hover {
  border-color: var(--color-primary);
  background-color: var(--color-primary-light);
}

.step-nav-item .step-number {
  width: 28px;
  height: 28px;
  font-size: 13px;
  background-color: var(--color-primary-light);
  color: var(--color-primary);
}

.step-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-heading);
}

.process-content {
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding: 24px 0;
}

.process-step {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.step-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}

.step-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 8px;
  background-color: var(--color-primary);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-sm);
}

.step-header h2 {
  font-size: 20px;
  font-weight: 700;
}

.step-detail {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.step-task h3,
.step-prepare h3,
.step-result h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-heading);
}

.step-task p,
.step-result p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.step-prepare ul {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.step-prepare li {
  display: flex;
  gap: 8px;
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.step-prepare li::before {
  content: "•";
  color: var(--color-primary);
  font-weight: 700;
  flex-shrink: 0;
}

.related-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding-bottom: 24px;
}

.related-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 140px;
}

.related-card h3 {
  font-size: 16px;
  font-weight: 600;
}

.related-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ---------- 4.5 FAQ 页 ---------- */
.page-title-area {
  padding: 8px 0 16px;
}

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

.faq-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  padding: 24px 0;
}

.faq-intro-content h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

.faq-intro-content p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.faq-intro-media {
  aspect-ratio: 16 / 9;
  max-height: 240px;
}

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

.faq-category {
  padding: 32px 0;
  border-bottom: 1px solid var(--color-border);
}

.faq-category-header {
  margin-bottom: 20px;
}

.faq-category-header h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 6px;
}

.faq-category-header p {
  font-size: 14px;
  color: var(--color-text-secondary);
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item[open] {
  border-color: var(--color-border-dark);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-heading);
  cursor: pointer;
  list-style: none;
  min-height: 44px;
  transition: color var(--transition-fast);
}

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

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  color: var(--color-text-muted);
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

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

.faq-item p {
  padding: 0 20px 16px;
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  border-top: 1px solid var(--color-border);
  padding-top: 12px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding: 24px 0;
}

.related-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 140px;
}

.related-card h3 {
  font-size: 16px;
  font-weight: 600;
}

.related-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ---------- 4.6 关于页 ---------- */
.about-section {
  padding: 32px 0;
  border-bottom: 1px solid var(--color-border);
}

.about-section:last-of-type {
  border-bottom: none;
}

.about-section h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
}

.about-section p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 12px;
  max-width: 780px;
}

.purpose-section p:last-child {
  margin-bottom: 0;
}

.principle-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.principle-list li {
  display: flex;
  gap: 12px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--color-text-secondary);
  padding: 16px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.principle-list strong {
  font-weight: 600;
  color: var(--color-heading);
  flex-shrink: 0;
}

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

.entry-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 140px;
}

.entry-card h3 {
  font-size: 16px;
  font-weight: 600;
}

.entry-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 0;
}

.entry-card a {
  display: inline-block;
  margin-top: auto;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  min-height: 44px;
  padding-top: 8px;
  padding-bottom: 8px;
}

.compliance-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.compliance-list li {
  display: flex;
  gap: 8px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

.compliance-list li::before {
  content: "•";
  color: var(--color-primary);
  font-weight: 700;
  flex-shrink: 0;
}

/* ---------- 4.7 404 页 ---------- */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  padding: 40px 24px;
}

.error-section {
  max-width: 640px;
  width: 100%;
  text-align: center;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 72px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 16px;
}

.error-content h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 16px;
  color: var(--color-text-secondary);
  margin-bottom: 24px;
}

.error-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.error-links {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.error-links h2 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
}

.error-links ul {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.error-links a {
  font-size: 14px;
  color: var(--color-primary);
  padding: 6px 0;
  display: inline-block;
}

/* --------------------------------------------------------------------------
   5. Responsive 响应式
   768px 断点，适配手机端
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
  /* 页头 */
  .header-inner {
    padding: 0 16px;
    gap: 16px;
  }

  .brand-slogan {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: static;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background-color: var(--color-heading);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding: 8px 16px 16px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
  }

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

  .nav-link {
    display: block;
    padding: 14px 12px;
    font-size: 15px;
    border-radius: var(--radius-sm);
  }

  /* 页脚 */
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 40px 16px 24px;
  }

  .footer-brand,
  .footer-nav,
  .footer-boundary {
    text-align: left;
  }

  .footer-bottom {
    padding: 12px 16px;
  }

  /* 面包屑 */
  .breadcrumb,
  .breadcrumb-nav {
    padding: 12px 16px 0;
  }

  /* 首页 */
  .home-main {
    padding: 0 16px;
  }

  .hero {
    padding: 32px 0 24px;
  }

  .hero-container {
    grid-template-columns: 1fr;
    gap: 24px;
  }

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

  .hero-lead {
    font-size: 15px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-secondary {
    width: 100%;
  }

  .hero-figure {
    aspect-ratio: 16 / 10;
  }

  .content-media-primary {
    aspect-ratio: 16 / 9;
    margin-top: 24px;
  }

  .service-overview,
  .process-preview,
  .guide-preview,
  .faq-entry {
    padding: 32px 0;
  }

  .service-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .process-steps {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .step-item {
    flex-direction: row;
    align-items: center;
    flex-wrap: wrap;
  }

  .step-item .step-number {
    margin-right: 8px;
  }

  .step-item h3 {
    flex: 1;
  }

  .step-item p {
    width: 100%;
    padding-left: 40px;
  }

  .guide-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .section-footer {
    text-align: left;
  }

  .faq-item {
    padding: 14px 16px;
  }

  /* 内页通用 */
  .inner-main {
    padding: 0 16px 32px;
  }

  .page-header {
    padding: 16px 0 4px;
  }

  .page-title {
    font-size: 24px;
  }

  .page-brief {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 16px 0;
  }

  .brief-figure,
  .brief-media {
    max-height: 200px;
  }

  /* 侧栏布局 */
  .page-layout {
    padding: 0 16px 32px;
  }

  .sidebar-left {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .sidebar {
    position: static;
    order: 2;
    padding: 16px;
  }

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

  /* 服务页 */
  .content-section {
    padding: 24px 0;
  }

  .content-section h2 {
    font-size: 20px;
  }

  .card-grid.four-cols,
  .service-audience .card-grid.four-cols {
    grid-template-columns: 1fr;
  }

  .boundary-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .contact-links {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .content-figure {
    aspect-ratio: 16 / 9;
    max-height: 200px;
  }

  .capability-table,
  .data-table {
    min-width: 480px;
  }

  /* 指南页 */
  .step-block {
    padding: 20px;
  }

  .entry-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 流程页 */
  .step-nav {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .step-nav-item {
    padding: 10px 12px;
  }

  .process-step {
    padding: 20px;
  }

  .step-header {
    flex-wrap: wrap;
  }

  .related-cards {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* FAQ 页 */
  .faq-intro {
    grid-template-columns: 1fr;
    gap: 16px;
    padding: 16px 0;
  }

  .faq-intro-media {
    max-height: 200px;
  }

  .faq-category {
    padding: 24px 0;
  }

  .related-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 关于页 */
  .about-section {
    padding: 24px 0;
  }

  .entry-card-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .principle-list li {
    flex-direction: column;
    gap: 4px;
    padding: 14px 16px;
  }

  /* 404 */
  .error-code {
    font-size: 56px;
  }

  .error-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .error-actions .btn-primary,
  .error-actions .btn-secondary {
    width: 100%;
  }

  .error-links ul {
    flex-direction: column;
    gap: 8px;
  }

  /* 相关链接 */
  .related-links {
    padding: 16px;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .related-links-item + .related-links-item::before {
    content: none;
    margin-right: 0;
  }
}

/* 超小屏幕适配 */
@media (max-width: 480px) {
  .hero-title {
    font-size: 24px;
  }

  .step-nav {
    grid-template-columns: 1fr;
  }

  .brand-name {
    font-size: 18px;
  }

  .header-inner {
    height: 60px;
  }

  :root {
    --header-height: 60px;
  }
}