/* ==========================================================================
   51吃瓜入口 - 全站样式表
   高密度控制台风：紧凑间距、信息密集型布局、颜色仅用于意义表示
   ========================================================================== */

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

html {
  font-size: 16px;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: #1a1a1a;
  background: #f5f5f5;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a {
  color: #2980b9;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #1a5276;
  text-decoration: underline;
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: #1a1a1a;
}

/* --------------------------------------------------------------------------
   Layout / 布局骨架
   -------------------------------------------------------------------------- */
.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

.site-header {
  background: #1a1a1a;
  border-bottom: 3px solid #c0392b;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 20px;
}

.brand {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.5px;
}

.brand-slogan {
  font-size: 12px;
  color: #bbb;
  margin-top: 2px;
}

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

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

.nav-list a {
  display: block;
  padding: 8px 14px;
  color: #ddd;
  font-size: 15px;
  border-radius: 4px;
  transition: background 0.2s ease, color 0.2s ease;
}

.nav-list a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  text-decoration: none;
}

.nav-list a.is-current {
  color: #fff;
  background: #c0392b;
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px 10px;
  align-items: center;
  gap: 8px;
  color: #fff;
}

.nav-toggle-icon {
  display: block;
  width: 20px;
  height: 2px;
  background: #fff;
  position: relative;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 20px;
  height: 2px;
  background: #fff;
}

.nav-toggle-icon::before {
  top: -6px;
}

.nav-toggle-icon::after {
  top: 6px;
}

.nav-toggle-text {
  font-size: 14px;
}

.site-footer {
  background: #1a1a1a;
  color: #bbb;
  margin-top: auto;
  flex-shrink: 0;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 20px 20px;
  display: flex;
  gap: 40px;
  justify-content: space-between;
}

.footer-brand {
  max-width: 360px;
}

.footer-site-name {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 8px;
}

.footer-desc {
  font-size: 14px;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  gap: 48px;
}

.footer-col-title {
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 10px;
}

.footer-col li {
  margin-bottom: 6px;
}

.footer-col a {
  color: #bbb;
  font-size: 14px;
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid #333;
  padding: 14px 20px;
  text-align: center;
  font-size: 13px;
  color: #888;
}

/* 内页布局容器 */
.layout-shell {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 20px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 32px;
  align-items: start;
}

.page-layout {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 20px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 32px;
  align-items: start;
}

/* 侧栏在左的专题页 */
.sidebar-left {
  grid-template-columns: 280px minmax(0, 1fr);
}

.sidebar-left .main-content {
  min-width: 0;
}

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

/* 面包屑 */
.breadcrumb {
  font-size: 14px;
  color: #666;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

.breadcrumb a {
  color: #2980b9;
}

.breadcrumb a:hover {
  color: #1a5276;
}

.breadcrumb-sep {
  color: #aaa;
  margin: 0 2px;
}

.breadcrumb-current {
  color: #666;
}

/* 页面标题区 */
.page-header {
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid #e0e0e0;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: #1a1a1a;
  margin-bottom: 8px;
}

.page-description {
  font-size: 15px;
  color: #555;
  max-width: 720px;
}

/* 侧栏 */
.sidebar {
  min-width: 0;
}

.sidebar-block,
.sidebar-box,
.aside-card {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  padding: 16px;
  margin-bottom: 20px;
}

.sidebar-block h2,
.sidebar-box h2,
.aside-card h2,
.sidebar-title {
  font-size: 16px;
  font-weight: 700;
  color: #1a1a1a;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid #c0392b;
}

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

.sidebar-links a {
  font-size: 14px;
  color: #2980b9;
  display: inline-block;
  padding: 2px 0;
}

.sidebar-links a:hover {
  color: #1a5276;
}

.sidebar-note {
  font-size: 13px;
  color: #666;
  line-height: 1.6;
}

.sidebar-block p {
  font-size: 14px;
  color: #555;
}

/* --------------------------------------------------------------------------
   Components / 通用组件
   -------------------------------------------------------------------------- */
/* 区块标题 */
.section-heading {
  margin-bottom: 20px;
}

.section-heading h2 {
  font-size: 22px;
  font-weight: 700;
  color: #1a1a1a;
  margin-bottom: 4px;
  position: relative;
  padding-left: 12px;
}

.section-heading h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background: #c0392b;
  border-radius: 2px;
}

.section-desc {
  font-size: 14px;
  color: #666;
  margin-top: 4px;
}

.section-title {
  font-size: 20px;
  font-weight: 700;
  color: #1a1a1a;
  margin-bottom: 16px;
  position: relative;
  padding-left: 12px;
}

.section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background: #c0392b;
  border-radius: 2px;
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 10px 24px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 4px;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  text-align: center;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: #c0392b;
  color: #fff;
  border: 1px solid #c0392b;
}

.btn-primary:hover {
  background: #a93226;
  border-color: #a93226;
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: #2980b9;
  border: 1px solid #2980b9;
}

.btn-secondary:hover {
  background: #2980b9;
  color: #fff;
}

.btn-back {
  display: inline-block;
  padding: 10px 28px;
  background: #c0392b;
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  border-radius: 4px;
}

.btn-back:hover {
  background: #a93226;
  color: #fff;
  text-decoration: none;
}

/* 图片容器 */
figure {
  margin: 0;
}

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

/* --------------------------------------------------------------------------
   Pages / 首页
   -------------------------------------------------------------------------- */
.home-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Hero 焦点区 */
.hero-section {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 32px;
  padding: 40px 0 32px;
  align-items: center;
}

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

.hero-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  color: #1a1a1a;
  margin-bottom: 12px;
}

.hero-intro {
  font-size: 16px;
  color: #555;
  line-height: 1.7;
  margin-bottom: 20px;
  max-width: 560px;
}

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

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

.hero-figure {
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid #e0e0e0;
  background: #fff;
}

.hero-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

/* 频道分类导航 */
.channels-nav-section {
  padding: 24px 0;
  border-top: 1px solid #e0e0e0;
}

.channels-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.channel-tag {
  display: block;
  padding: 8px 18px;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-left: 3px solid #2980b9;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 600;
  color: #1a1a1a;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.channel-tag:hover {
  background: #f0f4f8;
  border-left-color: #c0392b;
  text-decoration: none;
}

/* 最新资讯列表 */
.latest-news-section {
  padding: 24px 0;
  border-top: 1px solid #e0e0e0;
}

.news-list {
  display: flex;
  flex-direction: column;
}

.news-item {
  padding: 16px 0;
  border-bottom: 1px solid #eee;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 16px;
}

.news-item:last-child {
  border-bottom: none;
}

.news-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 4px;
  grid-column: 1 / -1;
}

.news-title a {
  color: #1a1a1a;
}

.news-title a:hover {
  color: #c0392b;
}

.news-summary {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  grid-column: 1 / -1;
}

.news-item time {
  font-size: 13px;
  color: #999;
  grid-column: 1 / -1;
}

/* 专题推荐 */
.topic-cards-section {
  padding: 24px 0;
  border-top: 1px solid #e0e0e0;
}

.topic-cards-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.topic-card {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

.topic-figure {
  overflow: hidden;
}

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

.topic-card h3,
.topic-title {
  padding: 12px 16px 4px;
  font-size: 17px;
  font-weight: 600;
}

.topic-title a {
  color: #1a1a1a;
}

.topic-title a:hover {
  color: #c0392b;
}

.topic-summary {
  padding: 0 16px 16px;
  font-size: 14px;
  color: #666;
  line-height: 1.6;
}

/* 编辑推荐 */
.editor-picks-section {
  padding: 24px 0;
  border-top: 1px solid #e0e0e0;
}

.editor-picks-list {
  display: flex;
  flex-direction: column;
}

.pick-item {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid #eee;
}

.pick-item:last-child {
  border-bottom: none;
}

.pick-item::before {
  content: attr(data-index);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: #1a1a1a;
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  border-radius: 4px;
}

.pick-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.pick-title a {
  color: #1a1a1a;
}

.pick-title a:hover {
  color: #c0392b;
}

.pick-reason {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
}

/* 信息来源与反馈 */
.source-feedback-section {
  padding: 24px 0;
  border-top: 1px solid #e0e0e0;
  margin-bottom: 32px;
}

.source-feedback-content {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  padding: 20px;
}

.source-feedback-content p {
  font-size: 14px;
  color: #555;
  line-height: 1.7;
  margin-bottom: 10px;
}

.source-feedback-content p:last-child {
  margin-bottom: 0;
}

/* --------------------------------------------------------------------------
   Pages / 频道分类页
   -------------------------------------------------------------------------- */
.page-channels .layout-shell {
  grid-template-columns: minmax(0, 1fr) 280px;
}

/* 频道目录 */
.channel-directory {
  margin-bottom: 32px;
}

.channel-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.channel-card {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

.channel-card:hover {
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
}

.card-media {
  overflow: hidden;
}

.card-media img {
  width: 100%;
  height: 120px;
  object-fit: cover;
}

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

.card-body h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.card-body h3 a {
  color: #1a1a1a;
}

.card-body h3 a:hover {
  color: #c0392b;
}

.card-body p {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-bottom: 10px;
}

.card-body a {
  font-size: 14px;
  font-weight: 600;
  color: #2980b9;
}

.card-body a:hover {
  color: #1a5276;
}

/* 频道内容预览 */
.channel-preview {
  margin-bottom: 32px;
}

.preview-list {
  display: flex;
  flex-direction: column;
}

.preview-item {
  padding: 14px 0;
  border-bottom: 1px solid #eee;
}

.preview-item:last-child {
  border-bottom: none;
}

.preview-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: #c0392b;
  background: #fdf2f1;
  border: 1px solid #f0c4bf;
  border-radius: 3px;
  padding: 2px 8px;
  margin-bottom: 6px;
}

.preview-item h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.preview-item h3 a {
  color: #1a1a1a;
}

.preview-item h3 a:hover {
  color: #c0392b;
}

.preview-item p {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-bottom: 6px;
}

.preview-date {
  font-size: 13px;
  color: #999;
}

/* --------------------------------------------------------------------------
   Pages / 内容专题页
   -------------------------------------------------------------------------- */
.topic-list-section {
  margin-bottom: 32px;
}

.topic-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.topic-card {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

.topic-card:hover {
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
}

.topic-card-img {
  width: 100%;
  height: 140px;
  object-fit: cover;
}

.topic-card-body {
  padding: 14px 16px;
}

.topic-card-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.topic-card-title a {
  color: #1a1a1a;
}

.topic-card-title a:hover {
  color: #c0392b;
}

.topic-card-summary {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-bottom: 8px;
}

.topic-card-meta {
  font-size: 13px;
  color: #999;
}

/* 专题摘要 */
.topic-digest-section {
  margin-bottom: 32px;
}

.digest-list {
  display: flex;
  flex-direction: column;
}

.digest-item {
  padding: 14px 0;
  border-bottom: 1px solid #eee;
}

.digest-item:last-child {
  border-bottom: none;
}

.digest-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.digest-title a {
  color: #1a1a1a;
}

.digest-title a:hover {
  color: #c0392b;
}

.digest-text {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-bottom: 6px;
}

.digest-date {
  font-size: 13px;
  color: #999;
}

/* --------------------------------------------------------------------------
   Pages / 深度解读页
   -------------------------------------------------------------------------- */
.article-section {
  margin-bottom: 32px;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  padding: 24px;
}

.article-media {
  margin-bottom: 20px;
  border-radius: 4px;
  overflow: hidden;
}

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

.article-body {
  font-size: 16px;
  color: #333;
  line-height: 1.8;
}

.article-lead {
  font-size: 17px;
  font-weight: 600;
  color: #1a1a1a;
  line-height: 1.7;
  margin-bottom: 16px;
}

.article-body p {
  margin-bottom: 16px;
}

.article-body p:last-child {
  margin-bottom: 0;
}

/* 相关解读 */
.related-section {
  margin-bottom: 32px;
}

.related-section h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 16px;
  position: relative;
  padding-left: 12px;
}

.related-section h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background: #c0392b;
  border-radius: 2px;
}

.related-list {
  display: flex;
  flex-direction: column;
}

.related-list li {
  padding: 12px 0;
  border-bottom: 1px solid #eee;
}

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

.related-list a {
  font-size: 15px;
  font-weight: 600;
  color: #1a1a1a;
  display: block;
  margin-bottom: 2px;
}

.related-list a:hover {
  color: #c0392b;
}

.related-desc {
  font-size: 13px;
  color: #888;
}

/* --------------------------------------------------------------------------
   Pages / 实用指南页
   -------------------------------------------------------------------------- */
.guide-section {
  margin-bottom: 32px;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  padding: 24px;
}

.guide-section-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
  position: relative;
  padding-left: 12px;
}

.guide-section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background: #c0392b;
  border-radius: 2px;
}

.guide-intro {
  font-size: 14px;
  color: #666;
  margin-bottom: 20px;
}

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

.guide-step {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid #eee;
}

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

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: #1a1a1a;
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  border-radius: 50%;
}

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

.step-content h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.step-content p {
  font-size: 14px;
  color: #666;
  line-height: 1.7;
}

.guide-media {
  margin-top: 20px;
  border-radius: 4px;
  overflow: hidden;
}

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

.guide-media figcaption {
  padding: 10px 12px;
  font-size: 13px;
  color: #888;
  background: #f9f9f9;
  border: 1px solid #eee;
  border-top: none;
  border-radius: 0 0 4px 4px;
}

/* 反馈方式 */
.feedback-section {
  margin-bottom: 32px;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  padding: 24px;
}

.feedback-methods {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.feedback-method {
  padding: 16px;
  background: #f9f9f9;
  border: 1px solid #eee;
  border-radius: 6px;
}

.feedback-method h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #1a1a1a;
}

.feedback-method p {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
}

.feedback-note {
  margin-top: 16px;
  font-size: 13px;
  color: #888;
  line-height: 1.6;
  padding: 12px;
  background: #fdf8f0;
  border: 1px solid #f0e0c0;
  border-radius: 4px;
}

/* 相关链接（指南页） */
.related-links {
  margin-bottom: 32px;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  padding: 24px;
}

.related-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 16px;
  position: relative;
  padding-left: 12px;
}

.related-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background: #c0392b;
  border-radius: 2px;
}

.related-links .related-list li {
  padding: 10px 0;
}

.related-links .related-list a {
  font-size: 15px;
  color: #2980b9;
  font-weight: 400;
}

.related-links .related-list a:hover {
  color: #1a5276;
}

/* 指南侧栏 */
.guide-aside {
  min-width: 0;
}

.aside-card h2 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid #c0392b;
}

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

.aside-links a {
  font-size: 14px;
  color: #2980b9;
  display: inline-block;
  padding: 2px 0;
}

.aside-links a:hover {
  color: #1a5276;
}

/* --------------------------------------------------------------------------
   Pages / 404 页
   -------------------------------------------------------------------------- */
.error-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 20px;
  flex: 1 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.error-content {
  text-align: center;
  max-width: 480px;
  padding: 40px;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
}

.error-code {
  font-size: 64px;
  font-weight: 700;
  color: #c0392b;
  line-height: 1;
  margin-bottom: 12px;
}

.error-content h1 {
  font-size: 24px;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: #666;
  margin-bottom: 24px;
}

.error-alt {
  margin-top: 16px;
  font-size: 14px;
  color: #888;
}

.error-alt a {
  color: #2980b9;
  margin: 0 4px;
}

.error-alt a:hover {
  color: #1a5276;
}

/* --------------------------------------------------------------------------
   Responsive / 响应式
   -------------------------------------------------------------------------- */
/* 平板 */
@media (max-width: 992px) {
  .layout-shell,
  .page-layout {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 24px;
  }

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

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

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

  .feedback-methods {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .feedback-method {
    padding: 12px;
  }

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

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

/* 手机 */
@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
    min-height: 56px;
    flex-wrap: wrap;
  }

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

  .brand-slogan {
    display: none;
  }

  .nav-toggle {
    display: flex;
    margin-left: auto;
    min-height: 44px;
    min-width: 44px;
    justify-content: center;
  }

  .site-nav {
    width: 100%;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    width: 100%;
    padding: 8px 0 12px;
    gap: 0;
  }

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

  .nav-list li {
    width: 100%;
  }

  .nav-list a {
    padding: 12px 16px;
    font-size: 16px;
    border-radius: 0;
    border-bottom: 1px solid #333;
    min-height: 44px;
    display: flex;
    align-items: center;
  }

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

  /* 布局切换 */
  .layout-shell,
  .page-layout {
    grid-template-columns: 1fr;
    padding: 16px;
    gap: 16px;
  }

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

  .sidebar-left .main-content {
    order: 1;
  }

  .sidebar-left .sidebar {
    order: 2;
  }

  /* 首页 */
  .home-main {
    padding: 0 16px;
  }

  .hero-section {
    grid-template-columns: 1fr;
    padding: 24px 0;
    gap: 20px;
  }

  .hero-content {
    order: 1;
  }

  .hero-media {
    order: 2;
  }

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

  .hero-intro {
    font-size: 15px;
  }

  .hero-actions {
    flex-direction: column;
    gap: 10px;
  }

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

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

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

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

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

  .feedback-methods {
    grid-template-columns: 1fr;
  }

  /* 页脚 */
  .footer-inner {
    flex-direction: column;
    gap: 24px;
    padding: 24px 16px 16px;
  }

  .footer-links {
    flex-direction: column;
    gap: 20px;
  }

  .footer-brand {
    max-width: 100%;
  }

  /* 内页 */
  .page-title {
    font-size: 22px;
  }

  .article-section,
  .guide-section,
  .feedback-section,
  .related-links {
    padding: 16px;
  }

  .article-media img {
    height: 180px;
  }

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

  .article-body {
    font-size: 15px;
  }

  .article-lead {
    font-size: 16px;
  }

  /* 编辑推荐 */
  .pick-item {
    grid-template-columns: 40px 1fr;
    gap: 10px;
  }

  .pick-item::before {
    width: 32px;
    height: 32px;
    font-size: 14px;
  }

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

  .error-content {
    padding: 24px;
    width: 100%;
  }

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

/* 小屏手机 */
@media (max-width: 390px) {
  .header-inner {
    padding: 0 12px;
  }

  .brand-name {
    font-size: 18px;
  }

  .home-main,
  .layout-shell,
  .page-layout {
    padding-left: 12px;
    padding-right: 12px;
  }

  .hero-title {
    font-size: 22px;
  }

  .news-title {
    font-size: 16px;
  }

  .topic-card h3,
  .topic-title {
    font-size: 16px;
  }

  .channel-tag {
    padding: 8px 14px;
    font-size: 13px;
  }

  .btn {
    padding: 10px 20px;
    font-size: 14px;
  }

  .step-number {
    width: 32px;
    height: 32px;
    font-size: 14px;
  }

  .guide-step {
    grid-template-columns: 38px 1fr;
    gap: 10px;
  }
}