/* ============================================================
   BASE — 全局基础样式
   ============================================================ */
:root {
  --bg-dark: #121212;
  --bg-panel: #1a1a2e;
  --bg-card: #1e1e2e;
  --bg-hover: #252538;
  --text-light: #f5f5f5;
  --text-muted: #a0a0b0;
  --text-dim: #6e6e80;
  --accent-red: #e50914;
  --accent-green: #46d369;
  --border-subtle: #2a2a3e;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --container-width: 1200px;
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition-fast: 0.2s ease;
  --transition-slow: 0.35s ease;
}

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

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

body {
  font-family: var(--font-stack);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-light);
  background-color: var(--bg-dark);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

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

ul,
ol {
  list-style: none;
}

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

h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.3;
}

h1 {
  font-size: 32px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

p {
  margin-bottom: 1rem;
}

/* ============================================================
   LAYOUT — 全站统一骨架
   ============================================================ */
.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.site-header {
  background-color: var(--bg-panel);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-light);
  white-space: nowrap;
  letter-spacing: 0.02em;
}

.brand:hover {
  color: var(--accent-green);
}

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

.nav-list {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-list li {
  position: relative;
}

.nav-list a {
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-list a:hover {
  color: var(--text-light);
  background-color: var(--bg-hover);
}

.nav-list a.is-current {
  color: var(--text-light);
  background-color: rgba(229, 9, 20, 0.15);
}

.nav-list a.is-current::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 2px;
  height: 2px;
  background-color: var(--accent-red);
  border-radius: 2px;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1px solid var(--border-subtle);
  flex-direction: column;
  gap: 5px;
}

.nav-toggle .toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--text-light);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

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

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

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

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

/* ============================================================
   COMPONENTS — 通用组件
   ============================================================ */
/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 16px;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
  min-height: 44px;
}

.btn-primary {
  background-color: var(--accent-red);
  color: #fff;
}

.btn-primary:hover {
  background-color: #c00812;
  color: #fff;
  transform: translateY(-2px);
}

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

.btn-secondary:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
  transform: translateY(-2px);
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 20px;
}

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

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

.breadcrumb-sep {
  color: var(--text-dim);
  font-size: 12px;
}

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

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

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 12px;
}

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

/* 区块标题 */
.section-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 16px;
}

/* 侧栏 */
.sidebar,
.page-sidebar {
  width: 260px;
  flex-shrink: 0;
}

.sidebar-inner {
  background-color: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px 16px;
  position: sticky;
  top: 84px;
}

.sidebar-title {
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

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

.sidebar-list a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.sidebar-list a:hover {
  color: var(--text-light);
  background-color: var(--bg-hover);
}

/* 内容区块 */
.content-section {
  margin-bottom: 40px;
}

.content-section h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.content-section p {
  color: var(--text-muted);
  margin-bottom: 16px;
}

/* 内容图片 */
.content-media {
  margin: 24px 0;
}

.content-media img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.content-media figcaption {
  font-size: 13px;
  color: var(--text-dim);
  padding: 8px 4px 0;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 16px;
  margin-bottom: 24px;
}

.content-media-inline {
  max-width: 640px;
}

/* 步骤条 */
.guide-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.guide-step {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px;
}

.guide-step .step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: var(--accent-red);
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 12px;
}

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

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

/* FAQ 手风琴 */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

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

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

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

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  color: var(--accent-green);
  transition: transform var(--transition-fast);
}

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

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

.faq-item p {
  padding: 0 20px 16px;
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* 相关链接块 */
.related-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

.related-link {
  display: block;
  padding: 14px 16px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  font-size: 14px;
  color: var(--text-muted);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.related-link:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

/* ============================================================
   PAGES — 页面专属样式
   ============================================================ */
/* ---------- 首页 ---------- */
.site-home .site-main {
  display: flex;
  flex-direction: column;
}

/* Hero 首屏 */
.hero {
  position: relative;
  min-height: 480px;
  display: flex;
  align-items: center;
  overflow: hidden;
}

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

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

.hero-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to right, rgba(18, 18, 18, 0.92) 0%, rgba(18, 18, 18, 0.7) 50%, rgba(18, 18, 18, 0.4) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 80px 24px;
  width: 100%;
}

.hero-title {
  font-size: 44px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 16px;
  max-width: 620px;
  line-height: 1.2;
}

.hero-slogan {
  font-size: 18px;
  color: rgba(245, 245, 245, 0.85);
  margin-bottom: 32px;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* 频道分类导航带 */
.channels-nav {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px 24px;
  width: 100%;
}

.channel-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.channel-tag {
  display: inline-flex;
  align-items: center;
  padding: 10px 20px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
  transition: border-color var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast);
  min-height: 44px;
}

.channel-tag:hover {
  border-color: var(--accent-red);
  color: var(--text-light);
  background-color: var(--bg-hover);
}

/* 专题推荐区 */
.topics {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px 24px;
  width: 100%;
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.topic-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-slow), border-color var(--transition-slow);
}

.topic-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-green);
}

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

.topic-card h3 {
  font-size: 18px;
  font-weight: 700;
  padding: 20px 20px 8px;
  color: var(--text-light);
}

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

.topic-card .card-link {
  display: inline-block;
  padding: 12px 20px 20px;
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-green);
  transition: color var(--transition-fast);
}

.topic-card .card-link:hover {
  color: var(--text-light);
}

/* 观看指南入口 */
.guide-entry {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px 24px;
  width: 100%;
}

.guide-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.step-card {
  background-color: var(--bg-panel);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-slow), border-color var(--transition-slow);
}

.step-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-red);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background-color: rgba(229, 9, 20, 0.2);
  color: var(--accent-red);
  font-size: 18px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}

.step-card h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 8px;
}

.step-card p {
  font-size: 14px;
  color: var(--text-muted);
  flex: 1;
  margin-bottom: 16px;
}

.step-card a {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-green);
}

.step-card a:hover {
  color: var(--text-light);
}

/* 内容参考 */
.reference {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px 24px 56px;
  width: 100%;
}

.reference p {
  color: var(--text-muted);
  font-size: 15px;
  max-width: 760px;
}

/* ---------- 频道分类页 ---------- */
.page-channels .page-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 32px;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 24px 56px;
  align-items: start;
}

.page-channels .inner-main {
  min-width: 0;
}

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

.page-channels .channel-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: transform var(--transition-slow), border-color var(--transition-slow);
}

.page-channels .channel-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-red);
}

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

.page-channels .channel-card-body {
  padding: 20px;
}

.page-channels .channel-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 8px;
}

.page-channels .channel-desc {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.page-channels .channel-note {
  font-size: 13px;
  color: var(--text-dim);
  margin-bottom: 0;
  border-top: 1px solid var(--border-subtle);
  padding-top: 8px;
}

/* ---------- 观看指南页 ---------- */
.page-guide .page-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 32px;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 24px 56px;
  align-items: start;
}

.page-guide .page-content {
  min-width: 0;
}

.page-guide .guide-section {
  margin-bottom: 48px;
}

.page-guide .guide-section h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.page-guide .guide-section > p {
  color: var(--text-muted);
  margin-bottom: 20px;
}

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

.page-guide .guide-section > p a:hover {
  color: var(--text-light);
}

.page-guide .guide-steps {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.page-guide .guide-step {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 16px;
  align-items: start;
}

.page-guide .guide-step .step-number {
  grid-row: span 2;
}

.page-guide .guide-media {
  margin-top: 24px;
}

.page-guide .guide-media img {
  width: 100%;
  height: auto;
  max-height: 400px;
  object-fit: cover;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.page-guide .guide-media figcaption {
  font-size: 13px;
  color: var(--text-dim);
  padding: 8px 4px 0;
}

.page-guide .guide-related h2 {
  font-size: 18px;
  margin-bottom: 16px;
  color: var(--text-light);
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 12px;
}

/* ---------- 专题页通用 ---------- */
.page-topic-1 .page-layout,
.page-topic-2 .layout-shell {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 32px;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 24px 56px;
  align-items: start;
}

.page-topic-1 .content-area,
.page-topic-2 .inner-main {
  min-width: 0;
}

/* ---------- 专题页 1：综艺 ---------- */
.page-topic-1 .show-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin: 24px 0;
}

.page-topic-1 .show-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: border-color var(--transition-fast), transform var(--transition-slow);
}

.page-topic-1 .show-card:hover {
  border-color: var(--accent-green);
  transform: translateY(-4px);
}

.page-topic-1 .show-card h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 8px;
}

.page-topic-1 .show-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
}

.page-topic-1 .analysis-block {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 16px;
}

.page-topic-1 .analysis-block h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 8px;
}

.page-topic-1 .analysis-block p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
}

.page-topic-1 .suggestion-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 16px 0 24px;
}

.page-topic-1 .suggestion-list li {
  display: flex;
  gap: 8px;
  font-size: 15px;
  color: var(--text-muted);
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
}

.page-topic-1 .suggestion-list strong {
  color: var(--accent-green);
  flex-shrink: 0;
}

.page-topic-1 .related-topics h2 {
  font-size: 18px;
  margin-bottom: 16px;
  color: var(--text-light);
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 12px;
}

.page-topic-1 .related-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-topic-1 .related-list a {
  display: block;
  padding: 10px 16px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-muted);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.page-topic-1 .related-list a:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

/* ---------- 专题页 2：纪录片 ---------- */
.page-topic-2 .article-content {
  min-width: 0;
}

.page-topic-2 .doc-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 16px 0;
}

.page-topic-2 .doc-list li {
  display: flex;
  gap: 8px;
  font-size: 15px;
  color: var(--text-muted);
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
}

.page-topic-2 .doc-list strong {
  color: var(--text-light);
  flex-shrink: 0;
}

.page-topic-2 .category-block {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 16px;
}

.page-topic-2 .category-block h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--accent-green);
  margin-bottom: 8px;
}

.page-topic-2 .category-block p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
}

.page-topic-2 .guide-steps {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 16px 0 24px;
}

.page-topic-2 .guide-steps li {
  display: flex;
  gap: 8px;
  font-size: 15px;
  color: var(--text-muted);
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
}

.page-topic-2 .guide-steps strong {
  color: var(--text-light);
  flex-shrink: 0;
}

/* ---------- 404 页 ---------- */
.site-error .error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  flex: 1;
}

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

.site-error .error-code {
  font-size: 96px;
  font-weight: 800;
  color: var(--accent-red);
  line-height: 1;
  margin-bottom: 24px;
}

.site-error .error-section h1 {
  font-size: 28px;
  margin-bottom: 16px;
}

.site-error .error-section p {
  color: var(--text-muted);
  margin-bottom: 32px;
}

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

/* ============================================================
   FOOTER — 页脚
   ============================================================ */
.site-footer {
  background-color: var(--bg-panel);
  border-top: 1px solid var(--border-subtle);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px 32px;
  display: grid;
  grid-template-columns: 1.2fr 2fr;
  gap: 48px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-light);
}

.footer-brand p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
  max-width: 280px;
}

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

.footer-group h3 {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 16px;
}

.footer-group ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-group a {
  font-size: 14px;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-subtle);
  padding: 20px 24px;
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: var(--text-dim);
  margin-bottom: 0;
}

/* ============================================================
   RESPONSIVE — 响应式
   ============================================================ */
@media (max-width: 1024px) {
  .page-topic-1 .show-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .header-inner {
    height: 56px;
    padding: 0 16px;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-subtle);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  }

  .nav-list {
    display: none;
    flex-direction: column;
    padding: 12px 16px;
    gap: 4px;
  }

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

  .nav-list a {
    width: 100%;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
  }

  .nav-list a.is-current::after {
    display: none;
  }

  /* 首页 */
  .hero {
    min-height: 400px;
  }

  .hero-content {
    padding: 60px 16px;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-slogan {
    font-size: 16px;
  }

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

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

  .channels-nav,
  .topics,
  .guide-entry,
  .reference {
    padding-left: 16px;
    padding-right: 16px;
  }

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

  .guide-steps {
    grid-template-columns: 1fr;
  }

  /* 内页布局切换 */
  .page-channels .page-layout,
  .page-guide .page-layout,
  .page-topic-1 .page-layout,
  .page-topic-2 .layout-shell {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 24px 16px 48px;
  }

  .page-channels .sidebar,
  .page-guide .page-sidebar,
  .page-topic-1 .sidebar,
  .page-topic-2 .sidebar {
    width: 100%;
    order: 2;
  }

  .page-channels .sidebar-inner,
  .page-guide .sidebar-inner,
  .page-topic-1 .sidebar-inner,
  .page-topic-2 .sidebar-inner {
    position: static;
  }

  .page-channels .inner-main,
  .page-guide .page-content,
  .page-topic-1 .content-area,
  .page-topic-2 .inner-main {
    order: 1;
  }

  .page-channels .channel-grid {
    grid-template-columns: 1fr;
  }

  .page-topic-1 .show-grid {
    grid-template-columns: 1fr;
  }

  .page-header {
    margin-bottom: 24px;
  }

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

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

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

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

  .footer-links {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .footer-bottom {
    padding: 16px;
  }

  /* 404 */
  .site-error .error-code {
    font-size: 72px;
  }

  .site-error .error-actions {
    flex-direction: column;
  }

  .site-error .error-actions .btn {
    width: 100%;
  }
}

@media (max-width: 390px) {
  .brand {
    font-size: 18px;
  }

  .footer-links {
    grid-template-columns: 1fr;
  }

  .hero-title {
    font-size: 28px;
  }

  .step-card {
    padding: 20px;
  }

  .page-channels .channel-card img {
    height: 140px;
  }

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

  .page-guide .guide-step {
    grid-template-columns: 32px 1fr;
    gap: 12px;
    padding: 16px;
  }

  .page-guide .guide-step .step-number {
    width: 28px;
    height: 28px;
    font-size: 13px;
  }
}