/* ============================================================
   九一视频 · 全站样式表
   城市地图风：浅色网格底纹、区域色块、路牌式按钮、虚线路径
   ============================================================ */

/* ============================================================
   Base —— 变量、重置、全局基础样式
   ============================================================ */
:root {
  --color-primary: #0d4f4f;
  --color-primary-dark: #0a3e3e;
  --color-accent: #f2c14e;
  --color-bg: #f5f1e8;
  --color-text: #1f2d2d;
  --color-text-light: #5a6b6b;
  --color-white: #ffffff;
  --color-border: #d9d2c4;
  --color-red: #c94f4f;
  --color-blue: #3f7fbf;
  --color-green: #3f9b6e;
  --color-orange: #e08a3c;
  --color-purple: #7a5ea8;
  --color-brown: #8a6d4f;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --container-width: 1200px;
  --header-height: 68px;
  --shadow-card: 0 2px 8px rgba(31, 45, 45, 0.08);
}

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

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

body {
  font-family: var(--font-family);
  font-size: 15px;
  line-height: 1.8;
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image:
    linear-gradient(rgba(13, 79, 79, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(13, 79, 79, 0.04) 1px, transparent 1px);
  background-size: 28px 28px;
  -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 0.2s ease;
}

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.4;
  color: var(--color-text);
}

h1 {
  font-size: 32px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

p {
  margin-bottom: 0;
}

/* ============================================================
   Layout —— 骨架布局：页头、主容器、页脚
   ============================================================ */

/* ---------- 页头 ---------- */
.site-header {
  background: 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;
  justify-content: space-between;
}

.brand-link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.5px;
}

.brand-slogan {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.75);
  line-height: 1.4;
}

/* ---------- 主导航 ---------- */
.site-nav .nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav .nav-list li a {
  display: block;
  padding: 8px 16px;
  color: rgba(255, 255, 255, 0.85);
  font-size: 15px;
  border-radius: var(--radius-sm);
  transition: background 0.2s ease, color 0.2s ease;
  position: relative;
}

.site-nav .nav-list li a:hover {
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.12);
}

.site-nav .nav-list li a.is-current {
  color: var(--color-primary);
  background: var(--color-accent);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
  width: 44px;
  height: 44px;
  justify-content: center;
  align-items: center;
}

.nav-toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-white);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

/* ---------- 主内容容器 ---------- */
.site-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

.home-main {
  padding-top: 0;
}

.inner-main {
  padding-top: 24px;
  padding-bottom: 64px;
  min-height: 60vh;
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--color-text-light);
  padding: 12px 0 20px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 28px;
}

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

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

.breadcrumb-sep {
  color: #a89f8f;
}

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

/* ---------- 页面标题区 ---------- */
.page-header {
  margin-bottom: 36px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.page-description {
  font-size: 15px;
  line-height: 1.8;
  color: var(--color-text-light);
  max-width: 760px;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--color-primary);
  border-top: 3px solid var(--color-accent);
  margin-top: 0;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 28px 24px 24px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  margin-bottom: 20px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  font-size: 14px;
  padding: 4px 0;
}

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

.footer-note {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.6;
  margin-bottom: 8px;
}

.footer-copyright {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
  line-height: 1.6;
}

/* ============================================================
   Components —— 通用组件
   ============================================================ */

/* ---------- 区块标题 ---------- */
.section-head {
  margin-bottom: 28px;
}

.section-head h2 {
  font-size: 24px;
  margin-bottom: 8px;
  position: relative;
  padding-left: 14px;
}

.section-head h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 4px;
  background: var(--color-accent);
  border-radius: 2px;
}

.section-head p {
  color: var(--color-text-light);
  font-size: 14px;
}

.section-intro {
  color: var(--color-text-light);
  font-size: 14px;
  margin-bottom: 24px;
}

.section-lead {
  color: var(--color-text-light);
  font-size: 14px;
  margin-bottom: 24px;
}

/* ---------- 路牌式按钮 ---------- */
.btn-guide,
.btn-features,
.btn-faq,
.btn-guide-more,
.btn-faq-more,
.btn-primary,
.btn-back,
.btn-channels {
  display: inline-block;
  padding: 10px 24px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  background: var(--color-primary);
  color: var(--color-white);
  border: 2px solid var(--color-primary);
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
}

.btn-guide:hover,
.btn-features:hover,
.btn-faq:hover,
.btn-guide-more:hover,
.btn-faq-more:hover,
.btn-primary:hover,
.btn-back:hover,
.btn-channels:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: var(--color-white);
}

/* ---------- 折叠问答 ---------- */
.faq-item {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

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

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

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  color: var(--color-primary);
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: transform 0.2s ease;
}

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

.faq-item p {
  padding: 0 20px 16px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--color-text-light);
}

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

/* ============================================================
   Pages —— 首页
   ============================================================ */

/* ---------- Hero 焦点区 ---------- */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
  padding: 56px 0 48px;
  border-bottom: 1px dashed var(--color-border);
}

.hero-text h1 {
  font-size: 34px;
  line-height: 1.4;
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 15px;
  line-height: 1.8;
  color: var(--color-text-light);
  margin-bottom: 24px;
  max-width: 480px;
}

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

.hero-figure {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--color-border);
}

.hero-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
}

/* ---------- 频道区域地图 ---------- */
.channel-map {
  padding: 48px 0;
  border-bottom: 1px dashed var(--color-border);
}

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

.channel-card {
  border-radius: var(--radius-md);
  padding: 4px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.channel-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 16px rgba(31, 45, 45, 0.12);
}

.channel-card-inner {
  background: var(--color-white);
  border-radius: calc(var(--radius-md) - 2px);
  padding: 24px 20px;
  min-height: 160px;
  display: flex;
  flex-direction: column;
}

.channel-card-inner h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.channel-card-inner p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
  flex: 1;
  margin-bottom: 12px;
}

.channel-card-inner a {
  font-size: 13px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.channel-card-inner a::after {
  content: "→";
  transition: transform 0.2s ease;
}

.channel-card-inner a:hover::after {
  transform: translateX(4px);
}

.channel-red {
  background: var(--color-red);
}

.channel-blue {
  background: var(--color-blue);
}

.channel-green {
  background: var(--color-green);
}

.channel-orange {
  background: var(--color-orange);
}

.channel-purple {
  background: var(--color-purple);
}

.channel-brown {
  background: var(--color-brown);
}

/* ---------- 专题片单预览 ---------- */
.features-preview {
  padding: 48px 0;
  border-bottom: 1px dashed var(--color-border);
}

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

.feature-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

.feature-card figure {
  overflow: hidden;
}

.feature-card figure img {
  width: 100%;
  height: 140px;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.feature-card:hover figure img {
  transform: scale(1.04);
}

.feature-card-body {
  padding: 16px 16px 20px;
}

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

.feature-card-body p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 12px;
}

.feature-card-body a {
  font-size: 13px;
  font-weight: 600;
}

.feature-card-body a::after {
  content: "→";
  margin-left: 4px;
}

/* ---------- 观看路径引导 ---------- */
.guide-steps {
  padding: 48px 0;
  border-bottom: 1px dashed var(--color-border);
}

.steps-row {
  display: flex;
  align-items: stretch;
  gap: 0;
  margin-bottom: 32px;
}

.step-item {
  flex: 1;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  position: relative;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--color-primary);
  color: var(--color-white);
  font-size: 14px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}

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

.step-item p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
}

.step-arrow {
  width: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  flex-shrink: 0;
}

.step-arrow::before {
  content: "";
  display: block;
  width: 0;
  height: 0;
  border-top: 8px solid transparent;
  border-bottom: 8px solid transparent;
  border-left: 14px solid var(--color-accent);
}

.step-arrow::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 4px;
  right: 4px;
  border-top: 2px dashed var(--color-accent);
  z-index: -1;
}

.btn-guide-more {
  margin-top: 8px;
}

/* ---------- FAQ 摘要 ---------- */
.faq-preview {
  padding: 48px 0;
}

.faq-preview-list {
  display: grid;
  gap: 12px;
  margin-bottom: 28px;
}

.faq-preview-list .faq-item p {
  font-size: 14px;
}

/* ============================================================
   Pages —— 频道分类页
   ============================================================ */

/* ---------- 频道地图图例 ---------- */
.map-legend {
  margin-bottom: 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-white);
}

.map-legend img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.map-legend figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--color-text-light);
  border-top: 1px solid var(--color-border);
}

/* ---------- 频道色块网格 ---------- */
.channel-grid .channel-block {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 32px 20px;
  border-radius: var(--radius-md);
  color: var(--color-white);
  text-align: center;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  min-height: 120px;
}

.channel-grid .channel-block:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 16px rgba(31, 45, 45, 0.18);
}

.channel-block-name {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 6px;
}

.channel-block-desc {
  font-size: 13px;
  opacity: 0.9;
}

.channel-block-red {
  background: var(--color-red);
}

.channel-block-blue {
  background: var(--color-blue);
}

.channel-block-green {
  background: var(--color-green);
}

.channel-block-orange {
  background: var(--color-orange);
}

.channel-block-purple {
  background: var(--color-purple);
}

.channel-block-brown {
  background: var(--color-brown);
}

/* ---------- 频道详述 ---------- */
.channel-details {
  padding: 48px 0;
  border-top: 1px dashed var(--color-border);
}

.channel-detail {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
  margin-bottom: 20px;
  border-left-width: 4px;
}

.channel-detail-documentary {
  border-left-color: var(--color-red);
}

.channel-detail-science {
  border-left-color: var(--color-blue);
}

.channel-detail-nature {
  border-left-color: var(--color-green);
}

.channel-detail-history {
  border-left-color: var(--color-orange);
}

.channel-detail-culture {
  border-left-color: var(--color-purple);
}

.channel-detail-food {
  border-left-color: var(--color-brown);
}

.channel-detail-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.channel-tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  color: var(--color-white);
  font-size: 13px;
  font-weight: 600;
  flex-shrink: 0;
}

.channel-tag-red {
  background: var(--color-red);
}

.channel-tag-blue {
  background: var(--color-blue);
}

.channel-tag-green {
  background: var(--color-green);
}

.channel-tag-orange {
  background: var(--color-orange);
}

.channel-tag-purple {
  background: var(--color-purple);
}

.channel-tag-brown {
  background: var(--color-brown);
}

.channel-detail-head h3 {
  font-size: 20px;
}

.channel-detail-body p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.8;
}

.channel-detail-body p + p {
  margin-top: 8px;
}

/* ---------- 跨频道关联推荐 ---------- */
.cross-recommends {
  padding: 32px 0;
  border-top: 1px dashed var(--color-border);
}

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

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

.cross-card h3 {
  font-size: 17px;
  margin-bottom: 10px;
  padding-left: 12px;
  border-left: 4px solid var(--color-accent);
}

.cross-card p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 12px;
}

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

/* ============================================================
   Pages —— 专题片单页
   ============================================================ */

/* ---------- 专题总览卡 ---------- */
.feature-overview {
  padding-bottom: 40px;
}

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

.overview-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.overview-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

.overview-card a {
  display: block;
  color: var(--color-text);
}

.overview-img {
  width: 100%;
  height: 130px;
  object-fit: cover;
}

.overview-card h3 {
  font-size: 16px;
  padding: 14px 16px 4px;
}

.overview-card p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
  padding: 0 16px 16px;
}

/* ---------- 专题详情 ---------- */
.feature-detail {
  padding: 40px 0;
  border-top: 1px dashed var(--color-border);
}

.detail-head {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 16px;
}

.detail-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--color-primary);
  color: var(--color-white);
  font-size: 18px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.detail-heading h2 {
  font-size: 22px;
  margin-bottom: 4px;
}

.detail-tag {
  font-size: 13px;
  color: var(--color-accent);
  font-weight: 600;
  background: var(--color-primary);
  display: inline-block;
  padding: 2px 10px;
  border-radius: var(--radius-sm);
}

.detail-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 24px;
  padding-left: 60px;
}

.feature-list {
  display: grid;
  gap: 12px;
}

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

.feature-item:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-card);
}

.item-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--color-accent);
  color: var(--color-primary);
  font-size: 13px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  margin-top: 2px;
}

.item-body h3 {
  font-size: 15px;
  margin-bottom: 4px;
}

.item-body p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ---------- 观看顺序说明 ---------- */
.watch-order {
  padding: 40px 0;
  border-top: 1px dashed var(--color-border);
}

.order-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 28px;
}

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

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--color-primary);
  color: var(--color-white);
  font-size: 16px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 12px;
}

.order-step p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
}

.order-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  align-items: center;
  font-size: 14px;
}

.order-links a {
  font-weight: 600;
}

/* ============================================================
   Pages —— 观看指南页
   ============================================================ */

/* ---------- 路线示意图 ---------- */
.route-map {
  margin-bottom: 36px;
}

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

.route-map-image img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.route-map-image figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--color-text-light);
  border-top: 1px solid var(--color-border);
}

.route-map-note {
  background: rgba(242, 193, 78, 0.15);
  border: 1px solid rgba(242, 193, 78, 0.4);
  border-radius: var(--radius-md);
  padding: 16px 20px;
}

.route-map-note p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.8;
}

/* ---------- 指南侧栏布局 ---------- */
.guide-wrapper {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 32px;
  align-items: start;
}

.guide-wrapper.sidebar-left {
  grid-template-columns: 260px 1fr;
}

.guide-wrapper.sidebar-left .guide-directory {
  grid-column: 1;
  grid-row: 1;
}

.guide-wrapper.sidebar-left .guide-steps {
  grid-column: 2;
  grid-row: 1;
}

/* ---------- 指南目录 ---------- */
.guide-directory {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  position: sticky;
  top: calc(var(--header-height) + 20px);
}

.directory-title {
  font-size: 16px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
}

.directory-list {
  display: grid;
  gap: 4px;
}

.directory-list li a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--color-text-light);
  border-radius: var(--radius-sm);
  border-left: 3px solid transparent;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.directory-list li a:hover {
  background: rgba(13, 79, 79, 0.06);
  color: var(--color-primary);
  border-left-color: var(--color-accent);
}

.directory-tip {
  margin-top: 16px;
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
  padding-top: 12px;
  border-top: 1px solid var(--color-border);
}

/* ---------- 指南步骤区 ---------- */
.guide-steps .section-title {
  font-size: 22px;
  margin-bottom: 8px;
}

.guide-steps .section-intro {
  margin-bottom: 28px;
}

.guide-step-block {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
  margin-bottom: 20px;
}

.step-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.guide-step-block .step-number {
  width: 36px;
  height: 36px;
  font-size: 16px;
  flex-shrink: 0;
}

.step-title {
  font-size: 18px;
}

.step-body p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 10px;
}

.step-body a {
  font-weight: 600;
}

.guide-switch-tips {
  background: rgba(13, 79, 79, 0.05);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  margin-top: 28px;
}

.switch-title {
  font-size: 16px;
  margin-bottom: 12px;
}

.switch-list {
  display: grid;
  gap: 8px;
}

.switch-list li {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  padding-left: 20px;
  position: relative;
}

.switch-list li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 600;
}

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

/* ---------- 示意图文区 ---------- */
.faq-intro-media {
  margin-bottom: 36px;
}

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

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

.faq-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--color-text-light);
  border-top: 1px solid var(--color-border);
}

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

.faq-layout.sidebar-left {
  grid-template-columns: 260px 1fr;
}

.faq-layout.sidebar-left .faq-directory {
  grid-column: 1;
  grid-row: 1;
}

.faq-layout.sidebar-left .faq-list {
  grid-column: 2;
  grid-row: 1;
}

/* ---------- FAQ 目录 ---------- */
.faq-directory {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  position: sticky;
  top: calc(var(--header-height) + 20px);
}

/* ---------- FAQ 分组列表 ---------- */
.faq-group {
  margin-bottom: 36px;
}

.faq-group-title {
  font-size: 18px;
  margin-bottom: 16px;
  padding-left: 12px;
  border-left: 4px solid var(--color-accent);
}

.faq-list .faq-item {
  margin-bottom: 10px;
}

.faq-list .faq-item p a {
  font-weight: 600;
}

/* ---------- 未覆盖问题入口 ---------- */
.faq-more {
  text-align: center;
  background: var(--color-white);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  padding: 40px 24px;
  margin-top: 40px;
}

.faq-more-title {
  font-size: 18px;
  margin-bottom: 12px;
}

.faq-more p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 20px;
}

/* ============================================================
   Pages —— 问题反馈页
   ============================================================ */

/* ---------- 状态总览 ---------- */
.status-overview {
  margin-bottom: 40px;
}

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

.status-badge {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
}

.badge-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-border);
}

.badge-dot-active {
  background: var(--color-green);
}

.badge-dot-open {
  background: var(--color-blue);
}

.badge-dot-updating {
  background: var(--color-accent);
}

.status-badge h3 {
  font-size: 16px;
}

.status-badge p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ---------- 异常类型列表 ---------- */
.error-types {
  margin-bottom: 40px;
}

.error-list {
  display: grid;
  gap: 12px;
}

.error-item {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.error-item h3 {
  font-size: 16px;
  padding-left: 12px;
  border-left: 4px solid var(--color-accent);
}

.error-item p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ---------- 准备信息 ---------- */
.prepare-info {
  margin-bottom: 40px;
}

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

.prepare-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
}

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

.prepare-card h3 {
  font-size: 15px;
  margin-bottom: 8px;
}

.prepare-card p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ---------- 处理原则 ---------- */
.policy-history {
  margin-bottom: 40px;
}

.policy-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 24px;
}

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

.step-marker {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--color-accent);
  color: var(--color-primary);
  font-size: 16px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 12px;
}

.policy-step h3 {
  font-size: 15px;
  margin-bottom: 8px;
}

.policy-step p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.7;
}

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

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

.feedback-flow figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--color-text-light);
  border-top: 1px solid var(--color-border);
}

/* ---------- 反馈页 FAQ 更多 ---------- */
.faq-more p a {
  font-weight: 600;
}

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

.error-main {
  min-height: 70vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 24px;
}

.error-panel {
  max-width: 560px;
  text-align: center;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 48px 40px;
  box-shadow: var(--shadow-card);
}

.error-code {
  font-size: 64px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
  margin-bottom: 12px;
}

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

.error-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 28px;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-bottom: 24px;
}

.error-help {
  font-size: 13px;
  color: var(--color-text-light);
}

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

/* ---------- 平板 1024px ---------- */
@media (max-width: 1024px) {
  .channel-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

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

  .hero {
    gap: 24px;
  }

  .hero-text h1 {
    font-size: 30px;
  }

  .hero-figure img {
    height: 260px;
  }
}

/* ---------- 手机 768px ---------- */
@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
    height: auto;
    min-height: var(--header-height);
    flex-wrap: wrap;
    position: relative;
  }

  .brand-link {
    padding: 12px 0;
  }

  .brand-slogan {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    width: 100%;
    flex-basis: 100%;
  }

  .site-nav .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0 0 12px;
    width: 100%;
  }

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

  .site-nav .nav-list li a {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-size: 15px;
  }

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

  .inner-main {
    padding-top: 16px;
    padding-bottom: 40px;
  }

  .breadcrumb {
    padding: 10px 0 16px;
    margin-bottom: 20px;
    font-size: 13px;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }

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

  .page-description {
    font-size: 14px;
  }

  .footer-inner {
    padding: 24px 16px 20px;
  }

  .footer-links {
    gap: 8px 16px;
  }

  /* ---------- 首页移动端 ---------- */
  .hero {
    grid-template-columns: 1fr;
    padding: 32px 0;
    gap: 20px;
  }

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

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

  .hero-actions {
    gap: 10px;
  }

  .hero-actions .btn-guide,
  .hero-actions .btn-features,
  .hero-actions .btn-faq {
    padding: 10px 16px;
    font-size: 14px;
  }

  .channel-map {
    padding: 32px 0;
  }

  .channel-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .channel-card-inner {
    min-height: 0;
    padding: 20px 16px;
  }

  .features-preview {
    padding: 32px 0;
  }

  .feature-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .feature-card figure img {
    height: 160px;
  }

  .guide-steps {
    padding: 32px 0;
  }

  .steps-row {
    flex-direction: column;
    gap: 0;
  }

  .step-item {
    width: 100%;
  }

  .step-arrow {
    width: 100%;
    height: 36px;
    justify-content: center;
  }

  .step-arrow::before {
    transform: rotate(90deg);
  }

  .step-arrow::after {
    top: 4px;
    bottom: 4px;
    left: 50%;
    right: auto;
    border-top: none;
    border-left: 2px dashed var(--color-accent);
    width: 0;
    height: auto;
  }

  .faq-preview {
    padding: 32px 0;
  }

  /* ---------- 频道页移动端 ---------- */
  .map-legend img {
    height: 160px;
  }

  .channel-detail {
    padding: 20px 16px;
  }

  .channel-detail-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .cross-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  /* ---------- 专题页移动端 ---------- */
  .overview-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .detail-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .detail-desc {
    padding-left: 0;
  }

  .feature-item {
    flex-direction: column;
    gap: 8px;
    padding: 16px;
  }

  .order-steps {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .order-links {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  /* ---------- 指南页移动端 ---------- */
  .route-map-image img {
    height: 180px;
  }

  .guide-wrapper {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .guide-wrapper.sidebar-left {
    grid-template-columns: 1fr;
  }

  .guide-wrapper.sidebar-left .guide-directory {
    grid-column: 1;
    grid-row: 1;
  }

  .guide-wrapper.sidebar-left .guide-steps {
    grid-column: 1;
    grid-row: 2;
  }

  .guide-directory {
    position: static;
    padding: 16px;
  }

  .directory-list {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
  }

  .directory-list li a {
    padding: 6px 12px;
    font-size: 13px;
  }

  .guide-step-block {
    padding: 20px 16px;
  }

  .step-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  /* ---------- FAQ 页移动端 ---------- */
  .faq-figure img {
    height: 140px;
  }

  .faq-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }

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

  .faq-layout.sidebar-left .faq-directory {
    grid-column: 1;
    grid-row: 1;
  }

  .faq-layout.sidebar-left .faq-list {
    grid-column: 1;
    grid-row: 2;
  }

  .faq-directory {
    position: static;
    padding: 16px;
  }

  .faq-group-title {
    font-size: 17px;
  }

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

  .faq-item p {
    padding: 0 16px 14px;
    font-size: 13px;
  }

  .faq-more {
    padding: 28px 16px;
  }

  /* ---------- 反馈页移动端 ---------- */
  .status-badges {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .prepare-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .policy-steps {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .feedback-flow img {
    height: 160px;
  }

  /* ---------- 404 移动端 ---------- */
  .error-main {
    padding: 40px 16px;
  }

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

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

  .error-title {
    font-size: 20px;
  }

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

  .error-actions a {
    text-align: center;
  }
}

/* ---------- 小屏手机 390px ---------- */
@media (max-width: 390px) {
  .brand-name {
    font-size: 20px;
  }

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

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

  .btn-guide,
  .btn-features,
  .btn-faq,
  .btn-guide-more,
  .btn-faq-more,
  .btn-primary,
  .btn-back,
  .btn-channels {
    padding: 10px 14px;
    font-size: 14px;
  }

  .channel-card-inner {
    padding: 16px 14px;
  }

  .feature-card figure img {
    height: 140px;
  }

  .channel-detail {
    padding: 16px 14px;
  }

  .status-badge {
    padding: 20px 16px;
  }

  .prepare-card {
    padding: 20px 16px;
  }

  .policy-step {
    padding: 20px 16px;
  }

  .error-panel {
    padding: 24px 16px;
  }
}

/* ============================================================
   Motion —— 滚动渐入（增强，不影响初始可见性）
   ============================================================ */

@media (prefers-reduced-motion: no-preference) {
  .channel-card,
  .feature-card,
  .overview-card,
  .step-item,
  .channel-detail,
  .status-badge,
  .prepare-card,
  .policy-step {
    animation: fade-in-up 0.5s ease both;
    animation-delay: calc(var(--index, 0) * 60ms);
  }

  @keyframes fade-in-up {
    from {
      opacity: 0;
      transform: translateY(12px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
}