/* ============================================================
   红果影视 - 全站样式表
   站点：sddanjilong.com
   定位：视频内容分类与观看信息整理站
   ============================================================ */

/* ============================================================
   1. Base - 基础变量、重置与全局字体
   ============================================================ */
:root {
  --color-primary: #1c3d5a;
  --color-accent: #e8890c;
  --color-bg: #f4f6f8;
  --color-text: #222a35;
  --color-card: #ffffff;
  --color-border: #dce3e8;
  --color-muted: #5a6b7a;
  --color-light: #eef2f5;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --container-width: 1200px;
  --font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --space-section: 32px;
}

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

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

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.8;
  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-primary);
  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 {
  line-height: 1.4;
  color: var(--color-primary);
  font-weight: 600;
}

/* ============================================================
   2. Layout - 全站骨架、页头、页脚、面包屑
   ============================================================ */

/* 站点主体骨架 */
.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background-color: var(--color-bg);
}

.site-main {
  flex: 1 0 auto;
  width: 100%;
}

/* 统一主容器宽度 */
.header-inner,
.footer-inner,
.inner-main,
.home-main {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding-left: 16px;
  padding-right: 16px;
}

/* ---------- 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 {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 16px;
  padding-top: 8px;
  padding-bottom: 8px;
}

.brand-logo {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 1px;
}

.brand-slogan {
  font-size: 12px;
  color: rgba(255, 255, 255, 0.7);
}

/* 主导航 */
.site-nav {
  display: block;
}

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

.nav-list li a {
  display: block;
  padding: 8px 14px;
  color: rgba(255, 255, 255, 0.85);
  font-size: 15px;
  border-radius: var(--radius-sm);
}

.nav-list li a:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.12);
}

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

/* 移动端汉堡按钮 */
.nav-toggle {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 10px;
  flex-direction: column;
  gap: 5px;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
}

.nav-toggle-icon {
  display: block;
  width: 24px;
  height: 2px;
  background-color: #ffffff;
  border-radius: 2px;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background-color: var(--color-primary);
  color: rgba(255, 255, 255, 0.8);
  margin-top: 48px;
}

.footer-inner {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  padding-top: 40px;
  padding-bottom: 32px;
}

.footer-title {
  font-size: 16px;
  color: #ffffff;
  margin-bottom: 12px;
  font-weight: 600;
}

.footer-links li a {
  display: inline-block;
  padding: 4px 0;
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding: 16px 0;
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  padding: 16px 0 8px;
  font-size: 14px;
  color: var(--color-muted);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

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

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

.breadcrumb-sep {
  color: #b0bac2;
}

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

/* ---------- 内页通用页面标题区 ---------- */
.inner-main {
  padding-top: 0;
  padding-bottom: 48px;
}

.page-header {
  padding: 8px 0 20px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 28px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
  line-height: 1.3;
}

.page-description {
  font-size: 15px;
  color: var(--color-muted);
  max-width: 720px;
  line-height: 1.7;
}

/* ---------- 通用区块标题 ---------- */
.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
  position: relative;
  padding-left: 14px;
}

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

.section-intro,
.section-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 20px;
  line-height: 1.7;
}

/* ---------- 按钮 ---------- */
.btn-primary,
.btn-secondary,
.next-step-btn,
.channel-link,
.topic-card-link,
.cross-link-btn {
  display: inline-block;
  padding: 10px 24px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-align: center;
  transition: background-color 0.2s ease, transform 0.15s ease;
  min-height: 44px;
  line-height: 1.4;
}

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

.btn-primary:hover {
  background-color: #d67c08;
  color: #ffffff;
  transform: translateY(-1px);
}

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

.btn-secondary:hover {
  background-color: var(--color-primary);
  color: #ffffff;
  transform: translateY(-1px);
}

/* ---------- 相关内容导航 ---------- */
.related-links {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px 16px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.related-links-label {
  font-size: 14px;
  color: var(--color-muted);
  font-weight: 600;
  margin-right: 4px;
}

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

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

/* ---------- 下一步引导区 ---------- */
.next-step-section {
  background-color: #eef2f5;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  padding: 36px 0;
  margin-top: 40px;
}

.next-step-section .section-title,
.next-step-title {
  font-size: 20px;
  margin-bottom: 8px;
  text-align: center;
  padding-left: 0;
}

.next-step-section .section-title::before,
.next-step-title::before {
  display: none;
}

.next-step-section .section-intro,
.next-step-desc {
  text-align: center;
  color: var(--color-muted);
  font-size: 15px;
  margin-bottom: 20px;
}

.step-actions,
.next-step-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* ---------- 图片容器与媒体 ---------- */
figure {
  margin: 0;
}

.focus-media,
.card-media,
.channel-media,
.topic-figure,
.scene-figure,
.faq-tabs-media,
.about-figure {
  overflow: hidden;
  background-color: var(--color-light);
}

.focus-media img,
.card-media img,
.channel-media img,
.topic-figure img,
.scene-figure img,
.faq-tabs-media img,
.about-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 视觉隐藏（仅用于无障碍标题） */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ============================================================
   3. Components - 通用组件
   ============================================================ */

/* 滚动渐入动画（不影响初始可见性） */
@keyframes fadeInUp {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 卡片悬浮效果 */
.video-card,
.channel-card,
.topic-card,
.faq-item,
.feedback-card,
.principle-card,
.cooperation-card,
.relation-item {
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.video-card:hover,
.channel-card:hover,
.topic-card:hover,
.feedback-card:hover,
.principle-card:hover,
.cooperation-card:hover,
.relation-item:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(28, 61, 90, 0.1);
}

/* 焦点视频卡片 */
.focus-card {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(28, 61, 90, 0.06);
}

.focus-media {
  aspect-ratio: 16 / 9;
}

.focus-body {
  padding: 20px;
}

.focus-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-primary);
}

.focus-desc {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

/* 快捷频道列表 */
.channel-shortcuts li a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  border-bottom: 1px solid var(--color-border);
  font-size: 14px;
  color: var(--color-text);
  transition: background-color 0.2s, color 0.2s;
}

.channel-shortcuts li a:hover {
  background-color: var(--color-light);
  color: var(--color-accent);
}

.channel-shortcuts li:last-child a {
  border-bottom: none;
}

/* 最新片单列表 */
.update-list li a {
  display: block;
  padding: 10px 14px;
  border-bottom: 1px solid var(--color-border);
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.5;
  transition: background-color 0.2s, color 0.2s;
}

.update-list li a:hover {
  background-color: var(--color-light);
  color: var(--color-accent);
}

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

/* 观看步骤条 */
.guide-steps {
  counter-reset: step;
}

.guide-steps li {
  position: relative;
  padding: 12px 0 12px 48px;
  border-bottom: 1px dashed var(--color-border);
}

.guide-steps li:last-child {
  border-bottom: none;
}

.step-num {
  position: absolute;
  left: 0;
  top: 14px;
  width: 32px;
  height: 32px;
  background-color: var(--color-primary);
  color: #ffffff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
}

.guide-steps li p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.6;
}

/* 专题片单列表（首页） */
.topic-list li a {
  display: flex;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--color-border);
  align-items: center;
}

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

.topic-cover {
  width: 72px;
  height: 48px;
  border-radius: var(--radius-sm);
  background-color: var(--color-light);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  color: var(--color-primary);
  overflow: hidden;
}

.topic-info {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.5;
  flex: 1;
}

.topic-info strong {
  display: block;
  color: var(--color-primary);
  font-weight: 600;
}

.topic-info span {
  font-size: 13px;
  color: var(--color-muted);
}

/* 新闻资讯列表 */
.news-items li a {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 14px;
  color: var(--color-text);
  gap: 12px;
}

.news-items li a:hover {
  color: var(--color-accent);
}

.news-items li:last-child a {
  border-bottom: none;
}

.news-items li a time {
  color: var(--color-muted);
  font-size: 13px;
  flex-shrink: 0;
}

/* FAQ 快捷入口列表 */
.faq-list li a {
  display: block;
  padding: 10px 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.5;
}

.faq-list li a:hover {
  color: var(--color-accent);
}

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

/* 视频卡片 */
.stream-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.video-card {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  display: flex;
  flex-direction: column;
}

.card-media {
  aspect-ratio: 16 / 9;
}

.card-body {
  padding: 16px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.card-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.card-tags {
  font-size: 13px;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.card-desc {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 12px;
  flex: 1;
}

.card-body a {
  font-size: 14px;
  color: var(--color-primary);
  font-weight: 600;
  align-self: flex-start;
}

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

/* FAQ 折叠面板 */
.faq-items {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

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

.faq-item summary {
  padding: 14px 18px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-primary);
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 40px;
  transition: background-color 0.2s;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  color: var(--color-accent);
  font-weight: 400;
}

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

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

.faq-answer {
  padding: 0 18px 14px;
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
}

/* 设备差异表格 */
.device-diff-table {
  width: 100%;
  border-collapse: collapse;
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  font-size: 14px;
}

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

.device-diff-table thead th {
  background-color: var(--color-primary);
  color: #ffffff;
  font-weight: 600;
}

.device-diff-table tbody tr:nth-child(even) {
  background-color: var(--color-light);
}

/* 侧边目录 */
.side-toc {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  align-self: flex-start;
}

.side-toc-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

.side-toc-list li a {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  border-left: 3px solid transparent;
  transition: background-color 0.2s, border-color 0.2s, color 0.2s;
}

.side-toc-list li a:hover {
  background-color: var(--color-light);
  color: var(--color-accent);
  border-left-color: var(--color-accent);
}

/* ============================================================
   4. Pages - 各页面特有样式
   ============================================================ */

/* ---------- 首页 ---------- */
.home-main {
  padding-top: 0;
  padding-bottom: 0;
}

/* 首屏三栏 */
.hero-section {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 20px;
  padding: 24px 0 32px;
}

.hero-block-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-accent);
  margin-bottom: 4px;
}

.hero-channels,
.hero-updates {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 16px 16px 8px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

/* 横向频道标签栏 */
.channel-bar {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 14px 16px;
  margin-bottom: 32px;
}

.channel-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.channel-tabs li a {
  display: inline-block;
  padding: 8px 18px;
  font-size: 14px;
  color: var(--color-primary);
  background-color: var(--color-light);
  border-radius: 20px;
  border: 1px solid var(--color-border);
  transition: background-color 0.2s, color 0.2s, border-color 0.2s;
}

.channel-tabs li a:hover {
  background-color: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
}

/* 最新片单内容流 */
.stream-section {
  margin-bottom: 32px;
}

.section-heading {
  margin-bottom: 20px;
}

.section-heading .section-title {
  margin-bottom: 6px;
}

/* 观看指南与专题片单组合区 */
.guide-topic-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 32px;
}

.watch-guide-steps,
.topic-playlist-list {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

.watch-guide-steps .guide-steps {
  margin-bottom: 16px;
}

/* 信息辅助区 */
.info-service-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 32px;
}

.site-news-list,
.faq-shortcuts {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

/* ---------- 频道精选页 ---------- */
.channel-intro {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 32px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

.channel-intro h2 {
  font-size: 20px;
  margin-bottom: 12px;
  color: var(--color-primary);
}

.channel-intro p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 10px;
}

.channel-intro p:last-child {
  margin-bottom: 0;
}

/* 频道网格 - 6个频道卡片 */
.channel-grid {
  margin-bottom: 32px;
}

.channel-grid > h2 {
  font-size: 20px;
  margin-bottom: 16px;
  color: var(--color-primary);
}

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

.channel-grid > h2 {
  grid-column: 1 / -1;
}

.channel-card {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  display: flex;
  flex-direction: column;
}

.channel-media {
  aspect-ratio: 16 / 10;
}

.channel-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.channel-body h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.channel-desc {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 10px;
}

.channel-scene {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 14px;
  padding: 8px 12px;
  background-color: var(--color-light);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-accent);
}

.channel-link {
  margin-top: auto;
  padding: 8px 16px;
  font-size: 14px;
  background-color: transparent;
  border: 1px solid var(--color-primary);
  color: var(--color-primary);
  border-radius: var(--radius-sm);
  align-self: flex-start;
  min-height: 40px;
}

.channel-link:hover {
  background-color: var(--color-primary);
  color: #ffffff;
}

/* 频道与片单关联区 */
.relation-section {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  margin-bottom: 16px;
}

.relation-section > h2 {
  font-size: 20px;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.relation-section > p {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 20px;
}

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

.relation-item {
  background-color: var(--color-light);
  border-radius: var(--radius-md);
  padding: 20px;
  border-top: 3px solid var(--color-accent);
}

.relation-item h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.relation-item p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 12px;
}

.relation-item a {
  font-size: 14px;
  color: var(--color-accent);
  font-weight: 600;
}

/* ---------- 专题片单页 ---------- */
.topic-index {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 32px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

.topic-index-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.topic-index-item a {
  display: inline-block;
  padding: 8px 18px;
  font-size: 14px;
  color: var(--color-primary);
  background-color: var(--color-light);
  border-radius: 20px;
  border: 1px solid var(--color-border);
  transition: background-color 0.2s, color 0.2s;
}

.topic-index-item a:hover {
  background-color: var(--color-accent);
  color: #ffffff;
  border-color: var(--color-accent);
}

/* 专题卡片 */
.topic-cards {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 32px;
}

.topic-card {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  display: grid;
  grid-template-columns: 320px 1fr;
}

.topic-card-media {
  position: relative;
}

.topic-figure {
  height: 100%;
  min-height: 220px;
}

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

.topic-figure figcaption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: rgba(28, 61, 90, 0.8);
  color: #ffffff;
  font-size: 13px;
  padding: 8px 12px;
}

.topic-card-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
}

.topic-card-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.topic-card-origin,
.topic-card-standard,
.topic-card-audience {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 10px;
}

.topic-card-origin strong,
.topic-card-standard strong,
.topic-card-audience strong {
  color: var(--color-primary);
  font-weight: 600;
}

.topic-card-link {
  margin-top: auto;
  padding: 8px 16px;
  font-size: 14px;
  background-color: var(--color-accent);
  color: #ffffff;
  border-radius: var(--radius-sm);
  align-self: flex-start;
  min-height: 40px;
  border: none;
}

.topic-card-link:hover {
  background-color: #d67c08;
  color: #ffffff;
}

/* 频道互跳区 */
.cross-links {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  margin-bottom: 16px;
}

.cross-links-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 16px;
}

.cross-link-col {
  background-color: var(--color-light);
  border-radius: var(--radius-md);
  padding: 20px;
  border-left: 3px solid var(--color-accent);
}

.cross-link-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.cross-link-desc {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 12px;
}

.cross-link-btn {
  padding: 8px 16px;
  font-size: 14px;
  background-color: transparent;
  border: 1px solid var(--color-primary);
  color: var(--color-primary);
  border-radius: var(--radius-sm);
  min-height: 40px;
  display: inline-block;
}

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

/* ---------- 观看指南页 ---------- */
.layout-shell.sidebar-right {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 28px;
  align-items: start;
}

.guide-content {
  min-width: 0;
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

.guide-scene-block {
  margin-bottom: 36px;
}

.guide-scene-block > h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-border);
}

.scene-figure {
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-md);
  margin-bottom: 16px;
}

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

.scene-figure figcaption {
  font-size: 13px;
  color: var(--color-muted);
  padding: 8px 4px;
  text-align: center;
}

.guide-scene-block > p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
}

.guide-scene-block .guide-steps {
  margin-bottom: 16px;
}

.device-diff-section {
  margin-bottom: 36px;
}

.device-diff-section > h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-border);
}

.guide-tips-section {
  background-color: var(--color-light);
  border-radius: var(--radius-md);
  padding: 20px;
}

.guide-tips-section > h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.guide-tips-section > p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 10px;
}

.guide-tips-list {
  margin-bottom: 12px;
}

.guide-tips-list li {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  padding: 6px 0;
}

.guide-tips-list li strong {
  color: var(--color-primary);
}

.guide-tips-section > p a {
  color: var(--color-accent);
  font-weight: 600;
}

/* 侧边目录吸顶 */
.side-toc {
  position: sticky;
  top: 80px;
}

/* ---------- 常见问题页 ---------- */
.faq-group-tabs {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 32px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

.faq-tabs-wrap {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 24px;
  align-items: center;
}

.faq-tabs-media {
  aspect-ratio: 4 / 3;
  border-radius: var(--radius-md);
  overflow: hidden;
}

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

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

.faq-tab-link {
  display: block;
  padding: 14px 16px;
  background-color: var(--color-light);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-primary);
  text-align: center;
  transition: background-color 0.2s, color 0.2s, border-color 0.2s;
}

.faq-tab-link:hover {
  background-color: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
}

/* FAQ 分组 */
.faq-groups {
  display: flex;
  flex-direction: column;
  gap: 28px;
  margin-bottom: 32px;
}

.faq-group {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
}

.faq-group-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 16px;
  padding-left: 12px;
  border-left: 4px solid var(--color-accent);
}

/* 反馈路径 */
.feedback-path {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  margin-bottom: 16px;
}

.feedback-intro {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 20px;
}

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

.feedback-card {
  background-color: var(--color-light);
  border-radius: var(--radius-md);
  padding: 20px;
  border-top: 3px solid var(--color-accent);
}

.feedback-card-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.feedback-card p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
}

/* ---------- 关于本站页 ---------- */
.about-intro {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 28px;
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  margin-bottom: 32px;
}

.intro-media {
  position: relative;
}

.about-figure {
  aspect-ratio: 4 / 3;
  border-radius: var(--radius-md);
  overflow: hidden;
}

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

.about-figure figcaption {
  font-size: 13px;
  color: var(--color-muted);
  padding: 8px 4px;
  text-align: center;
}

.intro-copy {
  min-width: 0;
}

.intro-copy .section-title {
  margin-bottom: 12px;
}

.intro-copy p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 12px;
}

.intro-copy p:last-child {
  margin-bottom: 0;
}

/* 编辑原则 */
.about-principles {
  margin-bottom: 32px;
}

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

.principle-card {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  border-top: 3px solid var(--color-primary);
}

.principle-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.principle-card p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
}

/* 版权说明 */
.about-copyright {
  background-color: var(--color-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  margin-bottom: 32px;
}

.copyright-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.copyright-item {
  padding: 16px;
  background-color: var(--color-light);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--color-accent);
}

.copyright-item-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 6px;
}

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

/* 合作说明 */
.about-cooperation {
  margin-bottom: 16px;
}

.cooperation-lead {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 20px;
}

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

.cooperation-card {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: 0 2px 8px rgba(28, 61, 90, 0.05);
  border-top: 3px solid var(--color-accent);
}

.cooperation-card-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.cooperation-card p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
}

/* ---------- 404 页面 ---------- */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 16px;
}

.error-section {
  text-align: center;
  max-width: 560px;
}

.error-code {
  font-size: 72px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 12px;
}

.error-title {
  font-size: 24px;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
}

.error-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.error-tip {
  font-size: 13px;
  color: var(--color-muted);
}

/* ============================================================
   5. Responsive - 响应式断点
   ============================================================ */

/* ---------- 平板（≤1024px） ---------- */
@media (max-width: 1024px) {
  /* 首页首屏改为两列 */
  .hero-section {
    grid-template-columns: 1fr 1fr;
  }

  .hero-focus {
    grid-column: 1 / -1;
  }

  /* 频道网格两列 */
  .channel-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 专题卡片改为上下结构 */
  .topic-card {
    grid-template-columns: 1fr;
  }

  .topic-figure {
    aspect-ratio: 16 / 9;
    min-height: 0;
  }

  .topic-figure img {
    aspect-ratio: 16 / 9;
  }

  /* 关于页改为单列 */
  .about-intro {
    grid-template-columns: 1fr;
  }

  /* FAQ 索引改为单列 */
  .faq-tabs-wrap {
    grid-template-columns: 1fr;
  }

  .faq-tabs-media {
    max-width: 320px;
  }
}

/* ---------- 手机（≤768px） ---------- */
@media (max-width: 768px) {
  /* 页头 */
  .header-inner {
    min-height: 56px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-primary);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
  }

  .nav-list {
    display: none;
    flex-direction: column;
    padding: 8px 16px 16px;
    gap: 2px;
  }

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

  .nav-list li a {
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    font-size: 16px;
  }

  /* 首页首屏单列 */
  .hero-section {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .hero-focus {
    grid-column: auto;
  }

  /* 视频卡片单列 */
  .stream-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 指南与专题区单列 */
  .guide-topic-section {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 信息辅助区单列 */
  .info-service-section {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 频道网格单列 */
  .channel-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 关联区单列 */
  .relation-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 互跳区单列 */
  .cross-links-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 指南页侧栏 */
  .layout-shell.sidebar-right {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .side-toc {
    position: static;
    order: -1;
  }

  /* FAQ 索引 */
  .faq-tabs-list {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  /* 反馈卡片单列 */
  .feedback-cards {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 原则网格双列 */
  .principles-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  /* 合作网格单列 */
  .cooperation-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

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

  /* 正文区域内边距缩小 */
  .guide-content,
  .watch-guide-steps,
  .topic-playlist-list,
  .site-news-list,
  .faq-shortcuts,
  .channel-intro,
  .relation-section,
  .topic-index,
  .cross-links,
  .faq-group-tabs,
  .faq-group,
  .feedback-path,
  .about-intro,
  .about-copyright,
  .about-cooperation {
    padding: 16px;
  }

  /* 步骤按钮区域 */
  .step-actions,
  .next-step-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .step-actions a,
  .next-step-actions a {
    text-align: center;
  }

  /* 页面标题 */
  .page-title {
    font-size: 24px;
  }

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

/* ---------- 小手机（≤480px） ---------- */
@media (max-width: 480px) {
  /* 品牌名称缩小 */
  .brand-name {
    font-size: 18px;
  }

  .brand-slogan {
    font-size: 11px;
  }

  /* 原则网格单列 */
  .principles-grid {
    grid-template-columns: 1fr;
  }

  /* 错误码缩小 */
  .error-code {
    font-size: 56px;
  }

  /* 按钮全宽 */
  .btn-primary,
  .btn-secondary,
  .next-step-btn,
  .channel-link,
  .topic-card-link,
  .cross-link-btn {
    width: 100%;
  }

  /* 频道标签单行滚动 */
  .channel-tabs {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 4px;
  }

  .channel-tabs li {
    flex-shrink: 0;
  }
}

/* 程序验收反馈：修复网格孤项 */
@media (min-width: 769px) {
  .channel-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}