/* ============================================================
   base 基础样式
   ============================================================ */
:root {
  --color-bg: #f5f7fa;
  --color-surface: #ffffff;
  --color-text: #2c3e50;
  --color-text-light: #5a6b7d;
  --color-primary: #3498db;
  --color-accent: #2ecc71;
  --color-danger: #e74c3c;
  --color-border: #e3e8ee;
  --color-code-bg: #f0f3f6;
  --color-code-text: #1a2b3c;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", "Fira Code", Consolas, "Liberation Mono", monospace;
  --container-width: 1200px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --shadow-sm: 0 1px 3px rgba(44, 62, 80, 0.08);
  --shadow-md: 0 2px 8px rgba(44, 62, 80, 0.1);
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

body.site-error {
  background-color: var(--color-bg);
}

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

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

a:hover {
  color: #217dbb;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-text);
}

/* ============================================================
   layout 布局骨架
   ============================================================ */

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

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

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

.brand-name {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0.01em;
}

.brand-slogan {
  font-size: 0.8rem;
  color: var(--color-text-light);
  border-left: 2px solid var(--color-primary);
  padding-left: 10px;
  line-height: 1.4;
}

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

.site-nav .nav-list a {
  display: block;
  padding: 8px 16px;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

.site-nav .nav-list a.is-current {
  background-color: rgba(52, 152, 219, 0.1);
  color: var(--color-primary);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: none;
  border: none;
  cursor: pointer;
}

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

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

.site-footer {
  background-color: var(--color-text);
  color: rgba(255, 255, 255, 0.85);
  margin-top: 64px;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
}

.footer-col h3 {
  font-size: 1rem;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

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

.footer-col .footer-links a {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition-fast);
}

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

.copyright {
  grid-column: 1 / -1;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  margin-top: 16px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.5);
  text-align: center;
}

/* ============================================================
   首页组件
   ============================================================ */

.home-main {
  width: 100%;
}

.hero-section {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.hero-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 56px 24px 48px;
}

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

.hero-title {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
  margin-bottom: 0;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--color-text-light);
  max-width: 480px;
  line-height: 1.8;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background-color: var(--color-primary);
  color: #ffffff;
  padding: 12px 28px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.hero-cta:hover {
  background-color: #217dbb;
  color: #ffffff;
  transform: translateY(-2px);
}

.hero-figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.hero-figure img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

.hero-figure figcaption {
  padding: 12px 16px;
  font-size: 0.85rem;
  color: var(--color-text-light);
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-border);
}

.channel-strip {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px 24px 8px;
}

.channel-strip .section-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.channel-strip .section-title::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 20px;
  background-color: var(--color-primary);
  border-radius: 2px;
}

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

.channel-tag {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  transition: border-color var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast);
}

.channel-tag:hover {
  border-color: var(--color-primary);
  background-color: rgba(52, 152, 219, 0.05);
  color: var(--color-primary);
}

.home-layout {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px 24px 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 40px;
  align-items: start;
}

.home-main-col {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 48px;
}

.latest-news .section-title,
.topics-recommend .section-title,
.editor-picks .section-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.latest-news .section-title::before,
.topics-recommend .section-title::before,
.editor-picks .section-title::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 20px;
  background-color: var(--color-primary);
  border-radius: 2px;
}

.news-timeline {
  position: relative;
  padding-left: 24px;
}

.news-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background-color: var(--color-border);
}

.news-item {
  position: relative;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.news-item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 22px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 2px solid var(--color-surface);
  box-shadow: 0 0 0 2px var(--color-primary);
}

.news-item time {
  display: inline-block;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--color-text-light);
  background-color: var(--color-code-bg);
  padding: 2px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
}

.news-item h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.news-item h3 a {
  color: var(--color-text);
}

.news-item h3 a:hover {
  color: var(--color-primary);
}

.news-item p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

.topic-cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.topic-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

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

.topic-figure {
  margin: 0;
  overflow: hidden;
}

.topic-figure img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.topic-card:hover .topic-figure img {
  transform: scale(1.03);
}

.topic-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  padding: 16px 16px 4px;
}

.topic-card p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  padding: 0 16px 16px;
  line-height: 1.6;
}

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

.pick-item {
  display: flex;
  gap: 16px;
  padding: 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow var(--transition-fast);
}

.pick-item:hover {
  box-shadow: var(--shadow-sm);
}

.pick-item::before {
  content: "★";
  font-size: 1.1rem;
  color: var(--color-accent);
  flex-shrink: 0;
  line-height: 1.6;
}

.pick-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.pick-item h3 a {
  color: var(--color-text);
}

.pick-item h3 a:hover {
  color: var(--color-primary);
}

.pick-item p {
  font-size: 0.88rem;
  color: var(--color-text-light);
  line-height: 1.6;
}

.home-sidebar {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

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

.sidebar-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-primary);
}

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

.sidebar-links a {
  display: block;
  padding: 8px 12px;
  font-size: 0.92rem;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

/* ============================================================
   内页通用
   ============================================================ */

.page-layout,
.layout-shell {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 24px 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 40px;
  align-items: start;
}

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

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
  padding: 8px 0;
}

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

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

.breadcrumb-sep {
  color: var(--color-border);
}

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

.page-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
}

.page-title {
  font-size: 1.8rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 12px;
}

.page-description {
  font-size: 1rem;
  color: var(--color-text-light);
  line-height: 1.7;
  max-width: 720px;
}

.section-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.section-title::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 20px;
  background-color: var(--color-primary);
  border-radius: 2px;
}

/* ============================================================
   内页组件 - 频道分类页
   ============================================================ */

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

.channel-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

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

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

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

.channel-card-body h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.channel-card-body p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.6;
  margin-bottom: 12px;
}

.channel-card-body a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.channel-card-body a:hover {
  color: #217dbb;
}

.channel-guide-section {
  margin-top: 48px;
}

.guide-content p {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 16px;
}

.sidebar-area {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.sidebar-inner {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.sidebar-inner h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-primary);
}

.sidebar-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sidebar-link {
  display: block;
  padding: 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.sidebar-link:hover {
  border-color: var(--color-primary);
  background-color: rgba(52, 152, 219, 0.03);
}

.sidebar-link h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 4px;
  color: var(--color-text);
}

.sidebar-link p {
  font-size: 0.85rem;
  color: var(--color-text-light);
  line-height: 1.5;
}

.sidebar-home-link {
  display: block;
  text-align: center;
  padding: 10px 16px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.sidebar-home-link:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ============================================================
   内页组件 - 内容专题页
   ============================================================ */

.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.topic-card-media {
  overflow: hidden;
}

.topic-card-media img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.topic-card:hover .topic-card-media img {
  transform: scale(1.03);
}

.topic-card-body {
  padding: 20px;
}

.topic-card-body h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.topic-card-body p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.6;
  margin-bottom: 12px;
}

.topic-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--color-text-light);
}

.topic-meta::before {
  content: "●";
  font-size: 0.6rem;
  color: var(--color-accent);
}

.topic-intro-section {
  margin-top: 48px;
}

.topic-intro-content p {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 16px;
}

.sidebar-block h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-primary);
}

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

.sidebar-channel-list a {
  display: block;
  padding: 8px 12px;
  font-size: 0.92rem;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

.sidebar-recommend-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sidebar-recommend-list a {
  display: block;
  padding: 10px 12px;
  font-size: 0.9rem;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.sidebar-recommend-list a:hover {
  border-color: var(--color-primary);
  background-color: rgba(52, 152, 219, 0.03);
}

/* ============================================================
   内页组件 - 热点解读页
   ============================================================ */

.article-body {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.article-hero {
  margin: 0 0 32px;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.article-hero img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.article-hero figcaption {
  padding: 10px 16px;
  font-size: 0.82rem;
  color: var(--color-text-light);
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-border);
}

.content-section {
  margin-bottom: 32px;
}

.content-section h2 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.content-section p {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.85;
  margin-bottom: 16px;
}

.related-links {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 2px solid var(--color-border);
}

.related-links h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
}

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

.related-links ul a {
  display: inline-block;
  font-size: 0.92rem;
  padding: 6px 0;
  color: var(--color-primary);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast);
}

.related-links ul a:hover {
  border-bottom-color: var(--color-primary);
}

.timeline-list {
  position: relative;
  padding-left: 24px;
}

.timeline-list::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background-color: var(--color-border);
}

.timeline-list li {
  position: relative;
  padding: 8px 0;
}

.timeline-list li::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 16px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-primary);
}

.sidebar {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.sidebar-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.sidebar-card h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-primary);
}

.sidebar-card .sidebar-links a {
  display: block;
  padding: 8px 12px;
  font-size: 0.92rem;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

/* ============================================================
   内页组件 - 专题解读页
   ============================================================ */

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 40px;
  align-items: start;
}

.article-content {
  min-width: 0;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.article-figure {
  margin: 0 0 32px;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.article-figure img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.article-figure figcaption {
  padding: 10px 16px;
  font-size: 0.82rem;
  color: var(--color-text-light);
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-border);
}

.analysis-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 16px;
}

.analysis-item {
  padding: 16px;
  background-color: var(--color-bg);
  border-left: 3px solid var(--color-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.analysis-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.analysis-item p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 0;
}

.further-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.further-list li a {
  display: block;
  padding: 10px 12px;
  font-size: 0.92rem;
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.further-list li a:hover {
  border-color: var(--color-primary);
  background-color: rgba(52, 152, 219, 0.03);
}

/* ============================================================
   404 错误页
   ============================================================ */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  flex: 1 0 auto;
}

.error-panel {
  text-align: center;
  max-width: 520px;
  padding: 48px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.error-code {
  font-family: var(--font-mono);
  font-size: 4rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
  margin-bottom: 16px;
}

.error-code::before {
  content: "> ";
  color: var(--color-accent);
}

.error-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.error-desc {
  font-size: 1rem;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 32px;
}

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

.btn-back,
.btn-channels {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 500;
  transition: background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.btn-back {
  background-color: var(--color-primary);
  color: #ffffff;
}

.btn-back:hover {
  background-color: #217dbb;
  color: #ffffff;
}

.btn-channels {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text);
}

.btn-channels:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ============================================================
   responsive 响应式
   ============================================================ */

@media (max-width: 1024px) {
  .hero-section {
    gap: 32px;
    padding: 40px 24px;
  }

  .hero-title {
    font-size: 1.7rem;
  }

  .home-layout,
  .page-layout,
  .layout-shell,
  .article-layout {
    grid-template-columns: minmax(0, 1fr) 280px;
    gap: 32px;
  }

  .channel-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 768px) {
  .header-inner {
    height: auto;
    min-height: 60px;
    padding: 8px 16px;
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: flex;
    margin-left: auto;
  }

  .site-nav {
    width: 100%;
  }

  .site-nav .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 0;
    border-top: 1px solid var(--color-border);
  }

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

  .site-nav .nav-list a {
    padding: 12px 16px;
    border-radius: 0;
    border-bottom: 1px solid var(--color-border);
  }

  .site-nav .nav-list a.is-current {
    background-color: var(--color-bg);
  }

  .hero-section {
    grid-template-columns: 1fr;
    padding: 32px 16px;
    gap: 24px;
  }

  .hero-content {
    text-align: left;
  }

  .hero-title {
    font-size: 1.5rem;
  }

  .hero-figure img {
    height: 220px;
  }

  .channel-strip {
    padding: 32px 16px 4px;
  }

  .home-layout,
  .page-layout,
  .layout-shell,
  .article-layout {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 24px 16px 0;
  }

  .home-main-col {
    gap: 40px;
  }

  .topic-cards,
  .topic-grid {
    grid-template-columns: 1fr;
  }

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

  .footer-inner {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
    padding: 40px 16px 24px;
  }

  .article-body,
  .article-content {
    padding: 20px;
  }

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

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

  .error-panel {
    padding: 32px 24px;
  }

  .error-code {
    font-size: 3rem;
  }
}

@media (max-width: 480px) {
  .header-inner {
    padding: 8px 12px;
  }

  .brand-slogan {
    display: none;
  }

  .brand-name {
    font-size: 1.2rem;
  }

  .hero-section {
    padding: 24px 12px;
  }

  .hero-title {
    font-size: 1.35rem;
  }

  .hero-desc {
    font-size: 0.95rem;
  }

  .hero-cta {
    padding: 10px 20px;
    font-size: 0.9rem;
  }

  .hero-figure img {
    height: 180px;
  }

  .channel-strip {
    padding: 24px 12px 4px;
  }

  .channel-tags {
    gap: 8px;
  }

  .channel-tag {
    padding: 6px 14px;
    font-size: 0.85rem;
  }

  .home-layout,
  .page-layout,
  .layout-shell,
  .article-layout {
    padding: 20px 12px 0;
  }

  .news-item {
    padding: 12px 0;
  }

  .news-item h3 {
    font-size: 1rem;
  }

  .news-item p {
    font-size: 0.85rem;
  }

  .topic-card h3 {
    font-size: 1rem;
  }

  .topic-card p {
    font-size: 0.85rem;
  }

  .pick-item {
    padding: 12px;
  }

  .pick-item h3 {
    font-size: 0.95rem;
  }

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

  .page-title {
    font-size: 1.4rem;
  }

  .page-description {
    font-size: 0.92rem;
  }

  .article-body,
  .article-content {
    padding: 16px;
  }

  .content-section h2 {
    font-size: 1.15rem;
  }

  .content-section p {
    font-size: 0.9rem;
  }

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

  .error-code {
    font-size: 2.5rem;
  }

  .error-title {
    font-size: 1.2rem;
  }

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

  .btn-back,
  .btn-channels {
    justify-content: center;
    width: 100%;
  }
}