/* ============================================================
   base — 全局基础样式
   ============================================================ */
:root {
  --color-bg: #f5f6f7;
  --color-surface: #ffffff;
  --color-text: #2c3e50;
  --color-text-light: #5d6d7e;
  --color-accent: #3498db;
  --color-accent-dark: #217dbb;
  --color-danger: #e74c3c;
  --color-border: #dfe4e8;
  --color-border-light: #eef0f2;
  --shadow-card: 0 1px 3px rgba(44, 62, 80, 0.08);
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --container-width: 1200px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

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

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

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

ul,
ol {
  list-style: none;
}

figure {
  margin: 0;
}

/* 默认隐藏移动端导航按钮（桌面端） */
.nav-toggle {
  display: none;
}

/* ============================================================
   layout — 全站布局骨架
   ============================================================ */

/* 站点统一宽度容器 */
.header-inner,
.footer-inner,
.site-main,
.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 24px;
}

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

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0;
}

.brand-slogan {
  font-size: 13px;
  color: var(--color-text-light);
  white-space: nowrap;
}

.site-nav {
  flex-shrink: 0;
}

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

.nav-link {
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-link:hover {
  background-color: var(--color-bg);
  color: var(--color-accent);
}

.nav-link.is-current {
  color: var(--color-accent);
  font-weight: 600;
  background-color: rgba(52, 152, 219, 0.08);
}

/* 全站主内容区 */
.site-main {
  flex: 1;
  width: 100%;
  padding-top: 32px;
  padding-bottom: 48px;
}

/* 内页主内容区（含面包屑和页标题） */
.inner-main {
  padding-top: 24px;
  padding-bottom: 56px;
}

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

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

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

.breadcrumb-sep {
  color: #b0b7bf;
  user-select: none;
}

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

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

.page-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
  margin-bottom: 10px;
}

.page-description {
  font-size: 16px;
  color: var(--color-text-light);
  max-width: 720px;
  line-height: 1.7;
}

/* 通用区块标题 */
.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

/* 页脚 */
.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border-light);
  padding: 40px 0 24px;
  margin-top: auto;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 40px;
  align-items: start;
}

.footer-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.footer-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.6;
  max-width: 320px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  justify-content: flex-end;
}

.footer-link {
  font-size: 14px;
  color: var(--color-text-light);
}

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

.footer-legal {
  grid-column: 1 / -1;
  padding-top: 20px;
  border-top: 1px solid var(--color-border-light);
  text-align: center;
}

.copyright {
  font-size: 13px;
  color: #8a949e;
}

/* ============================================================
   components — 通用组件
   ============================================================ */

/* 频道索引列表（首页侧栏 + 频道页侧栏共用） */
.channel-index-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.channel-index-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  font-size: 15px;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.channel-index-list a::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
  flex-shrink: 0;
}

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

/* 相关链接列表（通用） */
.related-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.related-list a {
  display: inline-block;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--color-accent);
  background-color: rgba(52, 152, 219, 0.06);
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease;
}

.related-list a:hover {
  background-color: rgba(52, 152, 219, 0.12);
}

/* 通用侧栏布局（主内容在前，aside 在后） */
.layout-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 32px;
  align-items: start;
  margin-top: 24px;
}

/* 侧栏在前的变体 */
.sidebar-left {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 32px;
  align-items: start;
  margin-top: 0;
}

/* ============================================================
   pages — 页面专属样式
   ============================================================ */

/* ---------- 首页 index.html ---------- */

/* 首屏左右不对称布局：窄侧频道索引 + 宽侧焦点报道 */
.hero-section {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 32px;
  align-items: start;
  margin-bottom: 48px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.hero-sidebar {
  background-color: var(--color-bg);
  border-radius: var(--radius-md);
  padding: 20px 16px;
}

.sidebar-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

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

.hero-title {
  font-size: 30px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-text);
  margin-bottom: 12px;
}

.hero-summary {
  font-size: 16px;
  color: var(--color-text-light);
  margin-bottom: 20px;
  max-width: 640px;
}

.hero-figure {
  margin-bottom: 20px;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-bg);
}

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

.hero-figure figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-text-light);
  background-color: var(--color-bg);
}

.hero-cta {
  display: inline-block;
  padding: 10px 24px;
  background-color: var(--color-accent);
  color: #ffffff;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  transition: background-color 0.2s ease;
}

.hero-cta:hover {
  background-color: var(--color-accent-dark);
  color: #ffffff;
}

/* 焦点报道 */
.focus-report {
  margin-bottom: 48px;
}

.focus-article {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 24px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 24px;
  align-items: center;
}

.focus-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 10px;
}

.focus-title a {
  color: var(--color-text);
}

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

.focus-summary {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 14px;
  line-height: 1.7;
}

.focus-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
}

.focus-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: var(--radius-md);
}

/* 最新资讯列表 */
.latest-news {
  margin-bottom: 48px;
}

.news-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 20px;
}

.news-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  transition: box-shadow 0.2s ease;
}

.news-item:hover {
  box-shadow: var(--shadow-card);
}

.news-card {
  padding: 18px 20px;
}

.news-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 6px;
  font-size: 13px;
  color: var(--color-text-light);
}

.news-channel {
  display: inline-block;
  padding: 2px 10px;
  background-color: rgba(52, 152, 219, 0.1);
  color: var(--color-accent);
  border-radius: 999px;
  font-size: 12px;
}

.news-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 4px;
}

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

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

.news-summary {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.6;
}

.more-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  padding: 8px 0;
}

/* 专题推荐区 */
.topics-feature {
  margin-bottom: 48px;
}

.topics-grid {
  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-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: var(--shadow-card);
}

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

.topic-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}

.topic-title a {
  color: var(--color-text);
}

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

.topic-excerpt {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.6;
  padding: 0 20px 20px;
}

.topic-title:not(:first-child) {
  padding-top: 20px;
}

.topic-card .topic-title {
  padding-left: 20px;
  padding-right: 20px;
}

.topic-card .topic-title:first-child {
  padding-top: 20px;
}

/* 编辑推荐 */
.editor-picks {
  margin-bottom: 48px;
}

.picks-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.pick-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  transition: box-shadow 0.2s ease;
}

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

.pick-card {
  padding: 18px 20px;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 16px;
  align-items: baseline;
}

.pick-title {
  font-size: 16px;
  font-weight: 600;
}

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

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

.pick-summary {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.6;
}

/* 信息来源与反馈 */
.source-info {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
}

.source-note,
.feedback-note {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 10px;
  line-height: 1.7;
  max-width: 760px;
}

.feedback-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 14px;
  font-weight: 600;
}

/* ---------- 频道分类页 51hlzx/channels.html ---------- */

.channel-aside {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 24px 20px;
  position: sticky;
  top: 88px;
}

.aside-title {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.channel-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  font-size: 15px;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.channel-link::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
  flex-shrink: 0;
}

.channel-link:hover {
  background-color: var(--color-bg);
  color: var(--color-accent);
}

.aside-tip {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border-light);
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.6;
}

.channel-detail {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

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

.channel-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.channel-desc {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 16px;
}

.channel-media {
  margin-bottom: 16px;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-bg);
}

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

.channel-media figcaption {
  padding: 8px 14px;
  font-size: 13px;
  color: var(--color-text-light);
}

.channel-sample {
  font-size: 14px;
  color: var(--color-text-light);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  align-items: center;
}

.channel-sample a {
  font-size: 14px;
  font-weight: 500;
}

/* 频道页相关链接 */
.related-links {
  margin-top: 32px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 24px;
}

/* ---------- 内容专题页 51hlzx/topics.html ---------- */

.topic-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 48px;
}

.section-desc {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 24px;
  max-width: 720px;
}

.topic-list .topic-card {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 0;
  overflow: hidden;
}

.topic-media {
  min-height: 100%;
}

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

.topic-body {
  padding: 24px 28px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.topic-body .topic-title {
  font-size: 20px;
  margin-bottom: 10px;
  padding: 0;
}

.topic-body .topic-title a {
  color: var(--color-text);
}

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

.topic-body .topic-excerpt {
  font-size: 15px;
  padding: 0;
  margin-bottom: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
}

.topic-meta {
  font-size: 13px;
  color: var(--color-text-light);
  margin-bottom: 14px;
}

.topic-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  align-self: flex-start;
}

/* 专题使用指南 */
.topic-guide {
  margin-bottom: 48px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
}

.topic-guide-content p {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 12px;
}

.topic-guide-content p:last-child {
  margin-bottom: 0;
}

/* 专题相关推荐 */
.topic-related {
  margin-bottom: 0;
}

.topic-related .related-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.topic-related .related-list li {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  transition: box-shadow 0.2s ease;
}

.topic-related .related-list li:hover {
  box-shadow: var(--shadow-card);
}

.topic-related .related-list a {
  display: block;
  padding: 0;
  background-color: transparent;
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
}

.topic-related .related-list a:hover {
  background-color: transparent;
}

.topic-related .related-list p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.6;
}

/* ---------- 实用指南页 51hlzx/guide.html ---------- */

.guide-content-wrap {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
}

.guide-intro {
  font-size: 16px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 32px;
}

.guide-section {
  margin-bottom: 36px;
}

.guide-section:last-of-type {
  margin-bottom: 0;
}

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

.guide-section p {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 14px;
}

.step-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 16px 0;
}

.step-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.7;
  background-color: var(--color-bg);
  border-radius: var(--radius-md);
  padding: 12px 16px;
}

.step-list li::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-accent);
  flex-shrink: 0;
  margin-top: 8px;
}

.step-list strong {
  color: var(--color-text);
  font-weight: 600;
}

.guide-figure {
  margin: 28px 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-bg);
}

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

.guide-figure figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-text-light);
}

/* 指南页相关推荐 */
.related-links {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  margin-top: 32px;
}

.related-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 16px;
}

.related-links .related-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.related-links .related-list a {
  background-color: var(--color-bg);
  text-align: center;
  padding: 12px 16px;
}

.related-links .related-list a:hover {
  background-color: rgba(52, 152, 219, 0.12);
}

/* ---------- 深度解读页 51hlzx/insight.html ---------- */

.insight-content {
  min-width: 0;
}

.insight-section {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin-bottom: 24px;
}

.insight-section h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.insight-section p {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 14px;
}

.insight-section p:last-child {
  margin-bottom: 0;
}

.insight-figure {
  margin: 20px 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-bg);
}

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

.insight-figure figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-text-light);
}

/* 深度解读相关推荐 */
.insight-related {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
}

.insight-related h2 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 16px;
}

.insight-related .related-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.insight-related .related-list a {
  background-color: var(--color-bg);
  text-align: center;
  padding: 12px 16px;
}

/* 深度解读侧栏 */
.insight-sidebar .sidebar-block {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  margin-bottom: 20px;
}

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

.insight-sidebar h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.sidebar-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.sidebar-list li {
  font-size: 14px;
  color: var(--color-text-light);
  padding: 6px 0;
  border-bottom: 1px dashed var(--color-border-light);
}

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

/* ---------- 404 页 ---------- */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 80px;
  padding-bottom: 80px;
}

.error-panel {
  text-align: center;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 56px 64px;
  max-width: 560px;
  width: 100%;
}

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

.error-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 24px;
  line-height: 1.7;
}

.btn-back-home {
  display: inline-block;
  padding: 10px 28px;
  background-color: var(--color-accent);
  color: #ffffff;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  transition: background-color 0.2s ease;
}

.btn-back-home:hover {
  background-color: var(--color-accent-dark);
  color: #ffffff;
}

.error-help {
  margin-top: 20px;
  font-size: 13px;
  color: #8a949e;
}

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

/* 平板及以下 */
@media (max-width: 1024px) {
  .hero-section {
    grid-template-columns: 220px minmax(0, 1fr);
    padding: 24px;
  }

  .focus-article {
    grid-template-columns: minmax(0, 1fr) 280px;
  }

  .sidebar-left {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 24px;
  }

  .layout-shell {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 24px;
  }

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

  .footer-links {
    justify-content: flex-start;
  }
}

/* 移动端断点 768px */
@media (max-width: 768px) {
  .header-inner,
  .footer-inner,
  .site-main,
  .inner-main {
    padding-left: 16px;
    padding-right: 16px;
  }

  .header-inner {
    height: 56px;
    gap: 12px;
  }

  .brand-slogan {
    display: none;
  }

  .brand-name {
    font-size: 20px;
  }

  /* 移动端导航按钮显示 */
  .nav-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: 8px 12px;
    cursor: pointer;
    color: var(--color-text);
    font-size: 13px;
  }

  .nav-toggle-icon {
    display: block;
    width: 16px;
    height: 2px;
    background-color: var(--color-text);
    position: relative;
    transition: background-color 0.2s ease;
  }

  .nav-toggle-icon::before,
  .nav-toggle-icon::after {
    content: "";
    position: absolute;
    left: 0;
    width: 16px;
    height: 2px;
    background-color: var(--color-text);
    transition: transform 0.2s ease;
  }

  .nav-toggle-icon::before {
    top: -5px;
  }

  .nav-toggle-icon::after {
    top: 5px;
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle-icon {
    background-color: transparent;
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
    transform: translateY(5px) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
    transform: translateY(-5px) rotate(-45deg);
  }

  /* 移动端导航列表收起，通过 .is-open 显示 */
  .site-nav {
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border-light);
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.08);
  }

  .nav-list {
    display: none;
    flex-direction: column;
    padding: 12px 16px;
    gap: 2px;
  }

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

  .nav-link {
    padding: 12px 16px;
    font-size: 16px;
    border-radius: var(--radius-sm);
  }

  /* 首页首屏改为单列 */
  .hero-section {
    grid-template-columns: 1fr;
    padding: 20px;
    gap: 20px;
  }

  .hero-sidebar {
    order: -1;
  }

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

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

  .focus-article {
    grid-template-columns: 1fr;
  }

  .focus-image {
    height: 180px;
  }

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

  .pick-card {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  /* 频道页：侧栏在前但保持核心内容可读 */
  .sidebar-left {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .channel-aside {
    position: static;
    order: -1;
  }

  .channel-index-list {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 4px;
  }

  .channel-index-list a {
    padding: 8px 14px;
    font-size: 14px;
  }

  .channel-index-list a::before {
    display: none;
  }

  .channel-media img {
    height: 160px;
  }

  /* 专题页卡片改为单列 */
  .topic-list .topic-card {
    grid-template-columns: 1fr;
  }

  .topic-media img {
    height: 180px;
    min-height: 0;
  }

  .topic-body {
    padding: 20px;
  }

  .topic-related .related-list {
    grid-template-columns: 1fr;
  }

  /* 指南页 */
  .guide-content-wrap {
    padding: 24px 20px;
  }

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

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

  /* 深度解读页 */
  .layout-shell {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .insight-section {
    padding: 20px;
  }

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

  .insight-sidebar {
    order: 2;
  }

  .insight-related .related-list {
    grid-template-columns: 1fr;
  }

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

  .footer-links {
    justify-content: flex-start;
    gap: 8px 16px;
  }

  .footer-legal {
    grid-column: 1;
  }

  /* 404 */
  .error-panel {
    padding: 40px 24px;
  }

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

/* 小屏手机 480px 以下 */
@media (max-width: 480px) {
  .section-title {
    font-size: 19px;
  }

  .news-card {
    padding: 14px 16px;
  }

  .news-meta {
    flex-wrap: wrap;
    gap: 6px;
  }

  .source-info {
    padding: 20px;
  }

  .topic-guide {
    padding: 20px;
  }

  .related-links {
    padding: 20px;
  }
}