/* ==========================================================================
   51吃瓜网 · 整站样式表
   研究报告风 · 深蓝 / 米白 / 灰
   ========================================================================== */

/* ==========================================================================
   Base — 变量、重置、全局基础
   ========================================================================== */

:root {
  --color-primary: #1a3a5c;
  --color-secondary: #3b6e9c;
  --color-bg: #f7f4ef;
  --color-text: #2b2b2b;
  --color-accent: #c2410c;
  --color-white: #ffffff;
  --color-border: #d8d2c8;
  --color-muted: #6b6b6b;
  --color-light: #e9e4dc;

  --font-serif: Georgia, "Songti SC", SimSun, serif;
  --font-sans: -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", Consolas, "Liberation Mono", Menlo, monospace;

  --container-width: 1200px;
  --content-max: 760px;
  --sidebar-width: 260px;

  --radius-sm: 4px;
  --radius-md: 8px;

  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 40px;
  --space-xl: 64px;

  --header-height: 72px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

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

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

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

a:hover {
  color: var(--color-accent);
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-serif);
  color: var(--color-primary);
  line-height: 1.3;
}

h1 {
  font-size: 32px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

p {
  margin-bottom: 16px;
}

blockquote {
  margin: 0 0 24px;
  padding: 16px 24px;
  border-left: 4px solid var(--color-accent);
  background-color: var(--color-light);
  font-style: italic;
  color: var(--color-primary);
}

blockquote p {
  margin-bottom: 0;
}

figure {
  margin: 0;
}

figcaption {
  font-size: 14px;
  color: var(--color-muted);
  text-align: center;
  padding: 8px 0 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 14px;
  margin-bottom: 24px;
}

th,
td {
  border: 1px solid var(--color-border);
  padding: 10px 12px;
  text-align: left;
}

th {
  background-color: var(--color-primary);
  color: var(--color-white);
  font-weight: 600;
}

tr:nth-child(even) {
  background-color: var(--color-light);
}

.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;
}

/* ==========================================================================
   Layout — 全站骨架容器
   ========================================================================== */

.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-main {
  flex: 1;
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

.inner-main {
  padding-top: 24px;
  padding-bottom: var(--space-xl);
}

/* 侧栏布局容器 —— 桌面双栏，手机主内容优先 */
.sidebar-left {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.sidebar-left .sidebar {
  order: 2;
}

.sidebar-left .site-main {
  order: 1;
  max-width: 100%;
}

.sidebar-left .sidebar {
  width: 100%;
}

/* 内页整体外壳 */
.layout-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.layout-shell .sidebar {
  order: 2;
}

.layout-shell .inner-main {
  order: 1;
  max-width: 100%;
}

/* ==========================================================================
   Components — 页头 / 导航 / 页脚 / 面包屑 / 按钮 / 卡片
   ========================================================================== */

/* ---------- 页头 ---------- */

.site-header {
  background-color: var(--color-primary);
  border-bottom: 3px solid var(--color-accent);
  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;
  gap: 24px;
}

.site-brand {
  margin: 0;
  flex-shrink: 0;
}

.site-brand a {
  font-family: var(--font-serif);
  font-size: 24px;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.02em;
}

.site-brand a:hover {
  color: var(--color-white);
  opacity: 0.85;
}

.site-slogan {
  margin: 0;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.7);
  flex-shrink: 0;
  line-height: 1.4;
}

/* ---------- 主导航 ---------- */

.main-nav {
  margin-left: auto;
}

.main-nav ul {
  display: flex;
  gap: 4px;
}

.main-nav li {
  position: relative;
}

.main-nav a {
  display: block;
  padding: 10px 14px;
  color: rgba(255, 255, 255, 0.85);
  font-size: 15px;
  font-weight: 500;
  position: relative;
  transition: color 0.2s ease;
}

.main-nav a::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 2px;
  height: 2px;
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s ease;
}

.main-nav a:hover {
  color: var(--color-white);
}

.main-nav a:hover::after,
.main-nav a.is-current::after {
  transform: scaleX(1);
}

.main-nav a.is-current {
  color: var(--color-white);
}

/* 导航汉堡按钮 —— 桌面隐藏 */
.nav-toggle {
  display: none;
}

/* ---------- 页脚 ---------- */

.site-footer {
  background-color: var(--color-primary);
  color: rgba(255, 255, 255, 0.8);
  padding: 48px 0 0;
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px 32px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.footer-col h2 {
  font-size: 16px;
  color: var(--color-white);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.footer-col li {
  margin-bottom: 8px;
}

.footer-col a {
  color: rgba(255, 255, 255, 0.75);
  font-size: 14px;
  line-height: 1.6;
}

.footer-col a:hover {
  color: var(--color-white);
}

.footer-brand {
  font-family: var(--font-serif);
  font-size: 18px;
  color: var(--color-white);
  margin-bottom: 8px;
}

.footer-col p {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.6;
}

.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 16px 24px;
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.55);
}

/* ---------- 面包屑 ---------- */

.breadcrumb {
  margin-bottom: 20px;
  font-size: 14px;
  color: var(--color-muted);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

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

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

.breadcrumb-sep {
  color: var(--color-border);
  margin: 0 2px;
}

.breadcrumb-current {
  color: var(--color-muted);
}

/* ---------- 页面标题区 ---------- */

.page-header {
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--color-primary);
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
}

.page-description {
  margin-top: 12px;
  font-size: 15px;
  color: var(--color-muted);
  max-width: var(--content-max);
}

/* ---------- 侧栏 ---------- */

.sidebar {
  padding: 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.sidebar h2 {
  font-size: 18px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-primary);
}

.sidebar li {
  margin-bottom: 4px;
}

.sidebar a {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  color: var(--color-text);
  border-left: 3px solid transparent;
  transition: all 0.2s ease;
}

.sidebar a:hover {
  background-color: var(--color-light);
  border-left-color: var(--color-accent);
  color: var(--color-primary);
}

.sidebar-block {
  margin-bottom: 32px;
}

.sidebar-block:last-child {
  margin-bottom: 0;
}

.sidebar-entry {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.sidebar-entry h2 {
  font-size: 18px;
  margin-bottom: 16px;
}

.sidebar-nav {
  margin-bottom: 24px;
}

.sidebar-nav h2 {
  font-size: 18px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-primary);
}

.sidebar-nav li {
  margin-bottom: 4px;
}

.sidebar-nav a {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  color: var(--color-text);
  border-left: 3px solid transparent;
  transition: all 0.2s ease;
}

.sidebar-nav a:hover {
  background-color: var(--color-light);
  border-left-color: var(--color-accent);
  color: var(--color-primary);
}

.sidebar-note {
  margin-top: 24px;
  padding: 16px;
  background-color: var(--color-light);
  border-radius: var(--radius-sm);
}

.sidebar-note h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.sidebar-note p {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 8px;
}

.text-link {
  font-size: 14px;
  font-weight: 600;
}

.side-extra {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.side-extra h2 {
  font-size: 18px;
  margin-bottom: 16px;
}

.side-extra li {
  margin-bottom: 4px;
}

.side-extra a {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  color: var(--color-text);
  border-left: 3px solid transparent;
  transition: all 0.2s ease;
}

.side-extra a:hover {
  background-color: var(--color-light);
  border-left-color: var(--color-accent);
  color: var(--color-primary);
}

/* ---------- 按钮 ---------- */

.btn,
.btn-primary,
.btn-secondary,
.error-btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  text-align: center;
  transition: all 0.2s ease;
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-white);
}

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

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

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

.btn {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.btn:hover {
  background-color: var(--color-secondary);
  color: var(--color-white);
}

/* ---------- 引用块 ---------- */

/* ---------- 卡片 ---------- */

/* ==========================================================================
   Components — 首页专属模块
   ========================================================================== */

/* ---------- 首屏 Hero ---------- */

.hero {
  position: relative;
  margin-bottom: 40px;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-primary);
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.35;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 48px 40px;
  color: var(--color-white);
}

.hero-content h1 {
  color: var(--color-white);
  font-size: 32px;
  margin-bottom: 16px;
  max-width: 640px;
}

.hero-content > p {
  font-size: 16px;
  color: rgba(255, 255, 255, 0.9);
  max-width: 560px;
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-entries {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  max-width: 720px;
}

.entry-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  padding: 20px;
  background-color: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: var(--radius-md);
  color: var(--color-white);
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.entry-card:hover {
  background-color: rgba(255, 255, 255, 0.22);
  color: var(--color-white);
  transform: translateY(-2px);
}

.entry-icon {
  font-size: 24px;
  line-height: 1;
}

.entry-label {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
}

.entry-text {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.5;
}

/* ---------- 快速通道 ---------- */

.quick-links {
  margin-bottom: 40px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.quick-links a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-primary);
  transition: all 0.2s ease;
}

.quick-links a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background-color: var(--color-light);
}

.quick-icon {
  font-size: 18px;
  line-height: 1;
}

/* ---------- 核心服务矩阵 ---------- */

.service-matrix {
  margin-bottom: 48px;
}

.service-matrix > h2 {
  margin-bottom: 12px;
}

.service-matrix > p {
  color: var(--color-muted);
  max-width: var(--content-max);
  margin-bottom: 24px;
}

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

.service-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.2s ease;
}

.service-card:hover {
  box-shadow: 0 4px 16px rgba(26, 58, 92, 0.1);
}

.service-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.service-card h3 {
  padding: 16px 20px 8px;
  font-size: 18px;
}

.service-card p {
  padding: 0 20px;
  font-size: 14px;
  color: var(--color-muted);
  flex: 1;
}

.service-card a {
  margin: 16px 20px 20px;
  font-size: 14px;
  font-weight: 600;
}

/* ---------- 今日吃瓜资源预览 ---------- */

.topics-preview {
  margin-bottom: 48px;
}

.topics-preview > h2 {
  margin-bottom: 12px;
}

.topics-preview > p {
  color: var(--color-muted);
  max-width: var(--content-max);
  margin-bottom: 24px;
}

.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.topic-tags a {
  display: inline-block;
  padding: 8px 16px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  font-size: 14px;
  color: var(--color-primary);
  transition: all 0.2s ease;
}

.topic-tags a:hover {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
}

.topic-sample {
  margin-bottom: 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-white);
}

.topic-sample img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.topic-sample figcaption {
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-muted);
  text-align: left;
  background-color: var(--color-light);
}

.topics-more {
  margin-top: 16px;
}

.topics-more a {
  font-weight: 600;
}

/* ---------- 服务方法与流程 ---------- */

.method-section {
  margin-bottom: 48px;
}

.method-section h2 {
  margin-bottom: 12px;
}

.method-section > p {
  color: var(--color-muted);
  max-width: var(--content-max);
  margin-bottom: 24px;
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 24px;
}

.process-steps li {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  position: relative;
}

.step-num {
  display: inline-block;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  text-align: center;
  line-height: 32px;
  margin-bottom: 12px;
}

.process-steps h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.process-steps p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

.method-note {
  font-size: 14px;
}

.method-note a {
  font-weight: 600;
}

/* ---------- 常见问题摘要 ---------- */

.faq-summary {
  margin-bottom: 48px;
  padding: 32px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.faq-summary h2 {
  margin-bottom: 12px;
}

.faq-summary > p {
  color: var(--color-muted);
  margin-bottom: 24px;
}

.faq-summary ul {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.faq-summary li {
  padding: 12px 16px;
  background-color: var(--color-light);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-secondary);
}

.faq-summary a {
  font-size: 15px;
  font-weight: 500;
}

/* ==========================================================================
   Components — 内页通用模块
   ========================================================================== */

/* ---------- 页面引导段 ---------- */

.page-heading {
  margin-bottom: 32px;
}

.page-heading p {
  color: var(--color-muted);
  max-width: var(--content-max);
}

/* ---------- 相关链接 ---------- */

.related-links {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.related-links-label {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
}

.related-links-item {
  font-size: 14px;
  padding: 6px 12px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  transition: all 0.2s ease;
}

.related-links-item:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ==========================================================================
   Pages — 服务页
   ========================================================================== */

.service-block {
  margin-bottom: 48px;
  padding: 32px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.block-header {
  margin-bottom: 20px;
}

.block-header h2 {
  margin-bottom: 8px;
}

.block-tag {
  display: inline-block;
  padding: 4px 12px;
  background-color: var(--color-light);
  border-radius: 20px;
  font-size: 13px;
  color: var(--color-secondary);
  font-weight: 600;
}

.service-media {
  margin-bottom: 24px;
}

.service-media img {
  width: 100%;
  max-height: 320px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.service-body p {
  line-height: 1.75;
}

.service-body h3 {
  margin-top: 24px;
  margin-bottom: 8px;
  font-size: 18px;
}

.guarantee-block {
  background-color: var(--color-light);
}

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

.guarantee-list li {
  padding: 16px;
  background-color: var(--color-white);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-secondary);
}

.guarantee-list h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.guarantee-list p {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 0;
  line-height: 1.6;
}

.entry-actions {
  margin: 40px 0;
}

.entry-actions h2 {
  margin-bottom: 16px;
}

.action-buttons {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* ==========================================================================
   Pages — 今日资源页
   ========================================================================== */

.page-title-area {
  margin-bottom: 32px;
}

.page-intro {
  color: var(--color-muted);
  max-width: var(--content-max);
}

.topic-overview {
  margin-bottom: 48px;
}

.topic-overview > h2 {
  margin-bottom: 12px;
}

.topic-overview > p {
  color: var(--color-muted);
  margin-bottom: 24px;
}

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

.topic-card {
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: 0 4px 12px rgba(26, 58, 92, 0.08);
}

.topic-card h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.topic-card p {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 12px;
  line-height: 1.6;
}

.topic-card a {
  font-size: 14px;
  font-weight: 600;
}

.topic-card-more {
  background-color: var(--color-light);
  border-style: dashed;
}

.topic-detail {
  margin-bottom: 48px;
  padding: 32px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.topic-tag {
  display: inline-block;
  padding: 4px 12px;
  background-color: var(--color-light);
  border-radius: 20px;
  font-size: 13px;
  color: var(--color-secondary);
  font-weight: 600;
  margin-bottom: 12px;
}

.content-figure {
  margin-top: 24px;
}

.content-figure img {
  width: 100%;
  max-height: 320px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.presentation-methods {
  margin-bottom: 48px;
}

.presentation-methods > h2 {
  margin-bottom: 12px;
}

.presentation-methods > p {
  color: var(--color-muted);
  margin-bottom: 24px;
}

.method-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.method-item {
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.method-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.method-item p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

.topic-example {
  margin-bottom: 48px;
}

.topic-example > h2 {
  margin-bottom: 12px;
}

.topic-example > p {
  color: var(--color-muted);
  margin-bottom: 24px;
}

.example-box {
  margin-bottom: 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.example-box figcaption {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  text-align: left;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 16px;
}

.example-list {
  list-style: none;
}

.example-list li {
  padding: 8px 0;
  border-bottom: 1px dashed var(--color-border);
  font-size: 14px;
  display: flex;
  gap: 8px;
}

.example-list li:last-child {
  border-bottom: none;
}

.example-list strong {
  color: var(--color-primary);
  flex-shrink: 0;
}

.access-guide {
  margin-bottom: 40px;
  padding: 32px;
  background-color: var(--color-light);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--color-accent);
}

.access-guide h2 {
  margin-bottom: 12px;
}

.access-guide p {
  color: var(--color-muted);
  max-width: var(--content-max);
}

.action-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

/* ==========================================================================
   Pages — 合作流程页
   ========================================================================== */

.process-flow {
  margin-bottom: 48px;
}

.process-flow > h2 {
  margin-bottom: 12px;
}

.section-lead {
  color: var(--color-muted);
  max-width: var(--content-max);
  margin-bottom: 24px;
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  counter-reset: step;
}

.process-step {
  position: relative;
  padding: 24px 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-align: center;
}

.step-number {
  display: inline-block;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  line-height: 40px;
  margin-bottom: 12px;
}

.process-step h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.process-step p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

.step-node {
  margin-top: 12px;
  font-size: 13px;
  color: var(--color-secondary);
  font-weight: 600;
}

.process-visual {
  margin-bottom: 48px;
}

.process-visual h2 {
  margin-bottom: 16px;
}

.process-figure {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.process-figure img {
  width: 100%;
  max-height: 360px;
  object-fit: cover;
}

.quick-start {
  margin-bottom: 48px;
  padding: 32px;
  background-color: var(--color-light);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--color-accent);
}

.quick-start h2 {
  margin-bottom: 12px;
}

.quick-start p {
  color: var(--color-muted);
  max-width: var(--content-max);
}

.quick-start-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.process-notes {
  margin-bottom: 48px;
}

.process-notes > h2 {
  margin-bottom: 12px;
}

.process-notes > p {
  color: var(--color-muted);
  margin-bottom: 24px;
}

.notes-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.notes-list li {
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  border-top: 3px solid var(--color-secondary);
}

.notes-list h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.notes-list p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.related-card {
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow 0.2s ease;
}

.related-card:hover {
  box-shadow: 0 4px 12px rgba(26, 58, 92, 0.08);
}

.related-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

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

/* ==========================================================================
   Pages — 使用指南页
   ========================================================================== */

.guide-block {
  margin-bottom: 48px;
  padding: 32px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.guide-block h2 {
  margin-bottom: 12px;
}

.guide-block > p {
  color: var(--color-muted);
  max-width: var(--content-max);
}

.guide-media {
  margin: 20px 0;
}

.guide-media figure {
  background-color: var(--color-light);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.guide-media img {
  width: 100%;
  max-height: 280px;
  object-fit: cover;
}

.guide-media figcaption {
  padding: 8px 12px;
  font-size: 13px;
}

.steps {
  margin: 20px 0;
}

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

.step-list li {
  position: relative;
  padding: 12px 0 12px 40px;
  border-bottom: 1px dashed var(--color-border);
  font-size: 15px;
}

.step-list li::before {
  counter-increment: guide-step;
  content: counter(guide-step);
  position: absolute;
  left: 0;
  top: 12px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-serif);
  font-size: 14px;
  font-weight: 700;
  text-align: center;
  line-height: 28px;
}

.step-list a {
  font-weight: 500;
}

.help-links {
  margin: 16px 0;
}

.help-links li {
  margin-bottom: 8px;
}

.help-links a {
  display: inline-block;
  padding: 8px 16px;
  background-color: var(--color-light);
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.2s ease;
}

.help-links a:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

/* ==========================================================================
   Pages — 常见问题页
   ========================================================================== */

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

.faq-section {
  margin-bottom: 48px;
}

.faq-section h2 {
  margin-bottom: 20px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-primary);
}

.faq-item {
  margin-bottom: 12px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.faq-item summary {
  padding: 16px 20px;
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 40px;
  transition: background-color 0.2s ease;
}

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

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

.faq-item[open] summary::after {
  transform: translateY(-50%) rotate(45deg);
}

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

.faq-answer {
  padding: 0 20px 16px;
  border-top: 1px solid var(--color-border);
}

.faq-answer p {
  padding-top: 16px;
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 0;
}

.faq-figure {
  margin-bottom: 20px;
}

.faq-figure img {
  width: 100%;
  max-height: 280px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.faq-aside {
  position: sticky;
  top: calc(var(--header-height) + 24px);
}

.aside-inner {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.aside-inner h2 {
  font-size: 18px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-primary);
}

.aside-inner nav ul {
  margin-bottom: 16px;
}

.aside-inner nav li {
  margin-bottom: 4px;
}

.aside-inner nav a {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--color-text);
  border-left: 3px solid transparent;
  transition: all 0.2s ease;
}

.aside-inner nav a:hover {
  background-color: var(--color-light);
  border-left-color: var(--color-accent);
  color: var(--color-primary);
}

.aside-help {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}

.aside-help p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 8px;
}

/* ==========================================================================
   Pages — 404 页
   ========================================================================== */

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

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

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

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

.error-desc {
  color: var(--color-muted);
  margin-bottom: 12px;
}

.error-tip {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 24px;
}

.error-btn {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.error-btn:hover {
  background-color: var(--color-secondary);
  color: var(--color-white);
}

/* ==========================================================================
   Responsive — 响应式断点
   ========================================================================== */

/* ---------- 桌面端（≥1024px） ---------- */

@media (min-width: 1024px) {

  .sidebar-left {
    grid-template-columns: var(--sidebar-width) 1fr;
    gap: 32px;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 32px 24px 0;
    align-items: start;
  }

  .sidebar-left .sidebar {
    order: 1;
    position: sticky;
    top: calc(var(--header-height) + 24px);
  }

  .sidebar-left .site-main {
    order: 2;
    max-width: 100%;
    padding: 0;
  }

  .layout-shell {
    grid-template-columns: var(--sidebar-width) 1fr;
    gap: 32px;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 32px 24px 0;
    align-items: start;
  }

  .layout-shell .sidebar {
    order: 1;
    position: sticky;
    top: calc(var(--header-height) + 24px);
  }

  .layout-shell .inner-main {
    order: 2;
    max-width: 100%;
    padding: 0 0 var(--space-xl);
  }

  .site-main {
    padding: 0 24px;
  }

  .inner-main {
    padding: 24px 0 var(--space-xl);
  }

  .header-inner {
    padding: 0 24px;
  }

  .footer-inner {
    padding: 0 24px 32px;
  }

}

/* ---------- 平板（768px–1023px） ---------- */

@media (max-width: 1023px) and (min-width: 768px) {

  .sidebar-left {
    grid-template-columns: 220px 1fr;
    gap: 24px;
    padding: 24px;
  }

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

  .sidebar-left .site-main {
    order: 2;
    max-width: 100%;
    padding: 0;
  }

  .layout-shell {
    grid-template-columns: 220px 1fr;
    gap: 24px;
    padding: 24px;
  }

  .layout-shell .sidebar {
    order: 1;
  }

  .layout-shell .inner-main {
    order: 2;
    max-width: 100%;
    padding: 0;
  }

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

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

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

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

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

  .faq-layout {
    grid-template-columns: 1fr;
  }

  .faq-aside {
    position: static;
  }

}

/* ---------- 手机（<768px） ---------- */

@media (max-width: 767px) {

  body {
    font-size: 15px;
  }

  h1 {
    font-size: 26px;
  }

  h2 {
    font-size: 21px;
  }

  h3 {
    font-size: 17px;
  }

  .site-main {
    padding: 0 16px;
  }

  .inner-main {
    padding: 16px 16px 48px;
  }

  /* 页头 */
  .header-inner {
    height: 60px;
    padding: 0 16px;
    gap: 12px;
    flex-wrap: wrap;
  }

  .site-brand a {
    font-size: 20px;
  }

  .site-slogan {
    display: none;
  }

  /* 汉堡按钮 */
  .nav-toggle {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 10px;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-sm);
    cursor: pointer;
    margin-left: auto;
    flex-shrink: 0;
  }

  .nav-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--color-white);
    transition: transform 0.25s ease, opacity 0.25s ease;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* 导航菜单 —— 手机收起，.is-open 展开 */
  .main-nav {
    flex-basis: 100%;
    margin-left: 0;
    order: 3;
  }

  .main-nav ul {
    display: none;
    flex-direction: column;
    gap: 0;
    padding: 8px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
  }

  .main-nav ul.is-open {
    display: flex;
  }

  .main-nav li {
    width: 100%;
  }

  .main-nav a {
    padding: 12px 16px;
    font-size: 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  }

  .main-nav a::after {
    display: none;
  }

  .main-nav a.is-current {
    background-color: rgba(255, 255, 255, 0.1);
  }

  /* 侧栏布局 —— 主内容优先 */
  .sidebar-left,
  .layout-shell {
    display: flex;
    flex-direction: column;
    padding: 0;
  }

  .sidebar-left .sidebar,
  .layout-shell .sidebar {
    order: 2;
    width: 100%;
    margin: 0;
    padding: 16px;
    border-radius: 0;
    border-left: none;
    border-right: none;
    border-bottom: none;
  }

  .sidebar-left .site-main,
  .layout-shell .inner-main {
    order: 1;
    width: 100%;
    padding: 16px;
  }

  /* 首页 hero */
  .hero-content {
    padding: 32px 24px;
  }

  .hero-content h1 {
    font-size: 26px;
  }

  .hero-entries {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .entry-card {
    padding: 16px;
  }

  /* 快速通道 */
  .quick-links {
    flex-direction: column;
    gap: 8px;
  }

  .quick-links a {
    width: 100%;
    justify-content: flex-start;
  }

  /* 服务卡片 */
  .service-cards {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .service-card img {
    height: 160px;
  }

  /* 专题标签 */
  .topic-tags {
    gap: 8px;
  }

  .topic-tags a {
    padding: 6px 12px;
    font-size: 13px;
  }

  .topic-sample img {
    height: 180px;
  }

  /* 流程步骤 */
  .process-steps {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .process-steps li {
    padding: 16px;
  }

  /* FAQ 摘要 */
  .faq-summary {
    padding: 24px 16px;
  }

  .faq-summary ul {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  /* 页脚 */
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 0 16px 24px;
  }

  .footer-col {
    padding-bottom: 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  }

  .footer-col:last-child {
    border-bottom: none;
  }

  /* 服务页 */
  .service-block {
    padding: 24px 16px;
  }

  .guarantee-list {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .action-buttons {
    flex-direction: column;
  }

  .action-buttons .btn {
    width: 100%;
  }

  /* 今日资源页 */
  .topic-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .topic-card {
    padding: 16px;
  }

  .method-list {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .method-item {
    padding: 16px;
  }

  .example-box {
    padding: 16px;
  }

  .content-figure img {
    max-height: 220px;
  }

  .action-links {
    flex-direction: column;
  }

  .action-links .btn-primary,
  .action-links .btn-secondary {
    width: 100%;
  }

  /* 流程页 */
  .process-step {
    padding: 20px 16px;
  }

  .notes-list {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .notes-list li {
    padding: 16px;
  }

  .related-grid {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .quick-start-actions {
    flex-direction: column;
  }

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

  /* 指南页 */
  .guide-block {
    padding: 24px 16px;
  }

  .guide-media img {
    max-height: 200px;
  }

  /* FAQ 页 */
  .faq-layout {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .faq-aside {
    position: static;
    order: 2;
  }

  .faq-item summary {
    padding: 14px 40px 14px 16px;
    font-size: 15px;
  }

  .faq-answer {
    padding: 0 16px 14px;
  }

  /* 404 */
  .error-content {
    padding: 32px 20px;
  }

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

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

  /* 页面标题 */
  .page-header {
    margin-bottom: 20px;
  }

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

  /* 页头在手机端允许换行 */
  .site-header {
    position: sticky;
  }

  .header-inner {
    align-items: center;
  }

  /* 手机端导航展开时 header 不再 sticky 固定高度 */
  .site-header.nav-open {
    position: relative;
  }

}

/* ---------- 超小屏（<360px） ---------- */

@media (max-width: 359px) {

  .site-brand a {
    font-size: 18px;
  }

  .hero-content {
    padding: 24px 16px;
  }

  .hero-content h1 {
    font-size: 24px;
  }

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

  .footer-inner {
    gap: 16px;
  }

}

/* 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;
  }
}