/* ==========================================================================
   黑料网网站 - 全站样式表
   版本: 1.0
   说明: 本文件为 dxbdciw.cn 全站唯一样式表，覆盖首页、内页、404页
   ========================================================================== */

/* ==========================================================================
   1. Base - 基础样式、变量与重置
   ========================================================================== */

:root {
  --color-primary: #1a2a3a;
  --color-primary-light: #2c3e50;
  --color-bg: #f5f3ef;
  --color-accent: #c0392b;
  --color-text: #2c3e50;
  --color-card: #ffffff;
  --color-border: #e0dcd5;
  --color-muted: #6b7a8a;
  --color-muted-light: #8a97a5;

  --font-heading: "Source Han Sans SC", "Noto Sans CJK SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;

  --container-width: 1200px;
  --content-width: 860px;
  --sidebar-width: 300px;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 8px;

  --shadow-sm: 0 1px 3px rgba(26, 42, 58, 0.08);
  --shadow-md: 0 4px 12px rgba(26, 42, 58, 0.1);
  --shadow-lg: 0 8px 24px rgba(26, 42, 58, 0.12);

  --transition-base: 0.2s ease;
  --transition-smooth: 0.3s ease;

  --header-height: 68px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;
}

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

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

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

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

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

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  color: var(--color-primary);
  line-height: 1.3;
  font-weight: 700;
}

figure {
  margin: 0;
}

/* ==========================================================================
   2. Layout - 全站布局骨架
   ========================================================================== */

/* 全站容器 */
.site-header,
.site-main,
.site-footer,
.footer-inner,
.layout-shell,
.page-layout,
.main-content,
.sidebar,
.sidebar-right,
.sidebar-area {
  width: 100%;
}

.header-inner,
.site-main,
.footer-inner,
.layout-shell,
.page-layout {
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* 站点主体结构 */
.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

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

/* 内页布局：主内容 + 侧栏 */
.layout-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  padding-top: 32px;
  padding-bottom: 64px;
}

/* 双栏布局：主内容在前，侧栏在后 */
.layout-shell.has-sidebar {
  grid-template-columns: minmax(0, 1fr) var(--sidebar-width);
  align-items: start;
}

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

.sidebar,
.sidebar-right,
.sidebar-area {
  min-width: 0;
}

/* 侧栏在左侧时（若 DOM 存在） */
.sidebar-left .layout-shell,
.sidebar-left.layout-shell {
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
}

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

.sidebar-left .sidebar,
.sidebar-left .sidebar-right {
  order: 1;
}

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

/* ---------- 3.1 页头 ---------- */
.site-header {
  background-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

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

.brand-name {
  font-family: var(--font-heading);
  font-size: 22px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 0.02em;
}

.brand-tagline {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.7);
  letter-spacing: 0.05em;
}

/* ---------- 3.2 主导航 ---------- */
.site-nav {
  display: flex;
  align-items: center;
}

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

.nav-list li a {
  display: block;
  padding: 10px 18px;
  font-size: 15px;
  color: rgba(255, 255, 255, 0.85);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-base), color var(--transition-base);
}

.nav-list li a:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.1);
}

.nav-list li a.is-current {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.18);
  font-weight: 600;
}

/* 汉堡菜单按钮 - 桌面隐藏 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 8px;
  gap: 5px;
}

.nav-toggle-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: #ffffff;
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

/* ---------- 3.3 面包屑 ---------- */
.breadcrumb {
  font-size: 14px;
  color: var(--color-muted);
  padding: 16px 0 0;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.breadcrumb ol {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

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

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

.breadcrumb-sep {
  color: var(--color-muted-light);
  margin: 0 2px;
}

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 600;
}

/* ---------- 3.4 页标题区 ---------- */
.page-header {
  padding: 24px 0 16px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 32px;
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.3;
  margin-bottom: 12px;
}

.page-description {
  font-size: 16px;
  color: var(--color-muted);
  line-height: 1.7;
  max-width: 760px;
}

/* ---------- 3.5 区块标题 ---------- */
.section-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 20px;
  position: relative;
  padding-left: 16px;
  line-height: 1.4;
}

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

.section-intro,
.block-intro {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
  line-height: 1.7;
  max-width: 720px;
}

/* ---------- 3.6 页脚 ---------- */
.site-footer {
  background-color: var(--color-primary);
  color: rgba(255, 255, 255, 0.8);
  margin-top: auto;
  flex-shrink: 0;
}

.footer-inner {
  padding-top: 48px;
  padding-bottom: 32px;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 48px;
}

.footer-brand-name {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
}

.footer-slogan {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.6;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-title {
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 16px;
}

.footer-group ul li {
  margin-bottom: 8px;
}

.footer-group ul li a {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition-base);
}

.footer-group ul li a:hover {
  color: #ffffff;
}

.footer-copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 16px 24px;
  text-align: center;
}

.footer-copyright p {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
  max-width: var(--container-width);
  margin: 0 auto;
}

/* ---------- 3.7 侧栏 ---------- */
.sidebar-block {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
}

.sidebar-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
}

.sidebar-list li,
.sidebar-links li {
  margin-bottom: 10px;
}

.sidebar-list li a,
.sidebar-links li a {
  font-size: 14px;
  color: var(--color-text);
  display: block;
  padding: 4px 0;
  transition: color var(--transition-base), padding-left var(--transition-base);
}

.sidebar-list li a:hover,
.sidebar-links li a:hover {
  color: var(--color-accent);
  padding-left: 6px;
}

/* ---------- 3.8 图片容器 ---------- */
.hero-figure,
.topic-card-media,
.channel-media,
.guide-media,
.sidebar-figure {
  overflow: hidden;
  border-radius: var(--radius-md);
}

.hero-figure img,
.topic-card-media img,
.channel-media img,
.guide-media img,
.sidebar-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 3.9 返回顶部按钮 ---------- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background-color: var(--color-primary);
  color: #ffffff;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base), background-color var(--transition-base);
  z-index: 99;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--color-accent);
}

/* ==========================================================================
   4. Pages - 首页
   ========================================================================== */

/* ---------- 4.1 首屏 Hero ---------- */
.hero-section {
  background-color: var(--color-primary);
  color: #ffffff;
  padding: 64px 24px;
  margin-bottom: 48px;
}

.home-main .hero-section {
  max-width: 100%;
}

.hero-section .hero-copy,
.hero-section .hero-figure {
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
}

.hero-section {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 48px;
  align-items: center;
}

.hero-copy h1 {
  font-size: 36px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 16px;
  line-height: 1.3;
}

.hero-copy h1 .accent {
  color: var(--color-accent);
}

.hero-position {
  font-size: 17px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.7;
  margin-bottom: 28px;
  max-width: 560px;
}

.hero-cta {
  display: inline-block;
  background-color: var(--color-accent);
  color: #ffffff;
  padding: 12px 28px;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 600;
  transition: background-color var(--transition-base), transform var(--transition-base);
}

.hero-cta:hover {
  background-color: #a93226;
  color: #ffffff;
  transform: translateY(-2px);
}

.hero-figure {
  background-color: rgba(255, 255, 255, 0.1);
  aspect-ratio: 4 / 3;
}

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

/* ---------- 4.2 频道导航带 ---------- */
.channel-nav-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin: 0 auto;
}

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

.channel-tag {
  display: inline-block;
  padding: 10px 20px;
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: 24px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text);
  transition: background-color var(--transition-base), border-color var(--transition-base), color var(--transition-base);
}

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

/* ---------- 4.3 最新动态列表 ---------- */
.latest-list-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin: 0 auto;
}

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

.list-item {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  border-left: 3px solid transparent;
}

.list-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-left-color: var(--color-accent);
}

.list-date {
  font-size: 13px;
  color: var(--color-muted);
  display: block;
  margin-bottom: 8px;
}

.list-item h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

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

.list-item h3 a:hover {
  color: var(--color-accent);
}

.list-item p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

/* ---------- 4.4 专题推荐区 ---------- */
.topic-cards-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin: 0 auto;
}

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

.topic-card {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  display: flex;
  flex-direction: column;
}

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

.topic-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  aspect-ratio: 16 / 9;
}

.topic-card h3 {
  font-size: 20px;
  font-weight: 600;
  padding: 20px 24px 8px;
}

.topic-card h3 a {
  color: var(--color-primary);
}

.topic-card h3 a:hover {
  color: var(--color-accent);
}

.topic-card p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  padding: 0 24px 24px;
  flex-grow: 1;
}

/* ---------- 4.5 编辑推荐 ---------- */
.editor-picks-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin: 0 auto;
}

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

.pick-item {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  border-left: 3px solid var(--color-accent);
}

.pick-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.pick-item h3 {
  font-size: 17px;
  font-weight: 600;
}

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

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

.pick-item p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

/* ---------- 4.6 信息来源说明 ---------- */
.source-info-section {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  box-shadow: var(--shadow-sm);
  max-width: var(--container-width);
  margin: 0 auto 48px;
}

.source-info-section .section-title {
  margin-bottom: 16px;
}

.source-info-section p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 8px;
}

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

/* ==========================================================================
   5. Pages - 内页通用
   ========================================================================== */

/* ---------- 5.1 频道分类页 ---------- */
.channel-list {
  margin-bottom: 48px;
}

.channel-item {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 24px;
  transition: box-shadow var(--transition-base);
}

.channel-item:hover {
  box-shadow: var(--shadow-md);
}

.channel-media {
  aspect-ratio: 4 / 3;
  background-color: var(--color-bg);
  border-radius: var(--radius-sm);
}

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

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

.channel-name {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

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

.channel-example {
  font-size: 14px;
  margin-bottom: 16px;
}

.channel-example a {
  color: var(--color-accent);
  font-weight: 500;
}

.channel-preview h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.channel-preview ul li {
  font-size: 14px;
  color: var(--color-muted);
  padding: 4px 0;
  position: relative;
  padding-left: 16px;
}

.channel-preview ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

/* 频道内容预览概览 */
.channel-preview-overview {
  margin-bottom: 48px;
}

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

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

.preview-col {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}

.preview-col h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.preview-col ul li {
  font-size: 13px;
  color: var(--color-muted);
  padding: 6px 0;
  line-height: 1.5;
}

/* ---------- 5.2 内容专题页 ---------- */
.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--sidebar-width);
  gap: 32px;
  align-items: start;
}

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

.topic-list-section {
  margin-bottom: 48px;
}

.topic-card {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
}

.topic-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.topic-card-media {
  aspect-ratio: 16 / 10;
  background-color: var(--color-bg);
}

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

.topic-card-body {
  padding: 24px;
  min-width: 0;
}

.topic-card-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
}

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

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

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

.topic-related-links {
  padding-top: 12px;
  border-top: 1px solid var(--color-border);
}

.topic-related-links li {
  font-size: 14px;
  color: var(--color-text);
  padding: 6px 0;
  position: relative;
  padding-left: 16px;
}

.topic-related-links li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

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

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

/* 专题详情预览 */
.topic-detail-preview {
  margin-bottom: 48px;
}

.preview-group {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 20px;
}

.preview-group-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.preview-group ul li {
  font-size: 14px;
  color: var(--color-text);
  padding: 8px 0;
  position: relative;
  padding-left: 16px;
}

.preview-group ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

/* 来源信息 */
.source-info {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 48px;
}

.source-info p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 8px;
}

/* ---------- 5.3 实用指南页 ---------- */
.content-block {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 32px;
}

.content-block h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 16px;
  position: relative;
  padding-left: 16px;
}

.content-block h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background-color: var(--color-accent);
  border-radius: 2px;
}

.step-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.step-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 20px;
  align-items: start;
}

.step-number {
  width: 48px;
  height: 48px;
  background-color: var(--color-primary);
  color: #ffffff;
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.step-body h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.step-body p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

/* 标准网格 */
.criteria-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.criterion-card {
  background-color: var(--color-bg);
  border-radius: var(--radius-md);
  padding: 20px;
  border-left: 3px solid var(--color-accent);
}

.criterion-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.criterion-card p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

/* 方法列表 */
.method-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 24px;
}

.method-item {
  background-color: var(--color-bg);
  border-radius: var(--radius-md);
  padding: 20px;
}

.method-item h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.method-item p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

.guide-media {
  aspect-ratio: 16 / 9;
  margin: 24px 0;
  background-color: var(--color-bg);
}

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

.guide-media figcaption {
  font-size: 13px;
  color: var(--color-muted);
  padding: 12px 0;
  text-align: center;
}

.related-links li {
  font-size: 15px;
  padding: 8px 0;
  position: relative;
  padding-left: 20px;
}

.related-links li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--color-accent);
}

.related-links a {
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
}

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

/* ---------- 5.4 历史归档页 ---------- */
.archive-section {
  margin-bottom: 48px;
}

.timeline-group {
  margin-bottom: 32px;
  position: relative;
  padding-left: 24px;
}

.timeline-group::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background-color: var(--color-border);
}

.timeline-year {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 16px;
  position: relative;
}

.timeline-year::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 8px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 2px solid var(--color-card);
}

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

.timeline-item {
  background-color: var(--color-card);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.timeline-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateX(4px);
}

.timeline-date {
  font-size: 13px;
  color: var(--color-muted);
  display: block;
  margin-bottom: 4px;
}

.timeline-item a {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-primary);
}

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

.timeline-source {
  font-size: 13px;
  color: var(--color-muted-light);
  margin-top: 4px;
  display: block;
}

/* 专题回顾 */
.topic-review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 32px;
}

.topic-review-card {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.topic-review-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.topic-review-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

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

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

.topic-review-summary {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

/* 侧栏图片 */
.sidebar-figure {
  background-color: var(--color-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  margin-bottom: 24px;
}

.sidebar-figure img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.sidebar-figure figcaption {
  font-size: 13px;
  color: var(--color-muted);
  padding: 12px 16px;
  text-align: center;
}

/* ==========================================================================
   6. Pages - 404
   ========================================================================== */

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

.error-content {
  text-align: center;
  max-width: 520px;
  margin: 0 auto;
}

.error-code {
  font-family: var(--font-heading);
  font-size: 96px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 16px;
}

.error-text {
  font-size: 16px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 24px;
}

.error-back {
  display: inline-block;
  background-color: var(--color-primary);
  color: #ffffff;
  padding: 12px 32px;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 600;
  transition: background-color var(--transition-base);
}

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

.error-help {
  font-size: 14px;
  color: var(--color-muted);
  margin-top: 24px;
}

/* ==========================================================================
   7. Responsive - 响应式
   ========================================================================== */

/* ---------- 平板 (≤1024px) ---------- */
@media (max-width: 1024px) {
  .layout-shell.has-sidebar,
  .page-layout {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 24px;
  }

  .channel-item {
    grid-template-columns: 200px 1fr;
    gap: 20px;
  }

  .topic-card {
    grid-template-columns: 240px 1fr;
  }

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

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

  .footer-inner {
    grid-template-columns: 1fr 1.5fr;
    gap: 32px;
  }
}

/* ---------- 手机 (≤768px) ---------- */
@media (max-width: 768px) {
  .header-inner,
  .site-main,
  .footer-inner,
  .layout-shell,
  .page-layout {
    padding-left: 16px;
    padding-right: 16px;
  }

  /* 汉堡菜单 */
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: static;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--color-primary);
    flex-direction: column;
    align-items: stretch;
    padding: 12px 16px;
    box-shadow: var(--shadow-lg);
    z-index: 99;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    gap: 4px;
  }

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

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

  /* 双栏变单栏 */
  .layout-shell.has-sidebar,
  .page-layout {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .sidebar,
  .sidebar-right,
  .sidebar-area {
    order: 2;
  }

  .main-content {
    order: 1;
  }

  /* 首页 hero */
  .hero-section {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 48px 16px;
  }

  .hero-copy h1 {
    font-size: 28px;
  }

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

  /* 首页专题卡片 */
  .topic-cards {
    grid-template-columns: 1fr;
  }

  /* 频道卡片 */
  .channel-item {
    grid-template-columns: 1fr;
  }

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

  /* 专题卡片 */
  .topic-card {
    grid-template-columns: 1fr;
  }

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

  /* 标准网格 */
  .criteria-grid {
    grid-template-columns: 1fr;
  }

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

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

  /* 预览网格 */
  .preview-grid {
    grid-template-columns: 1fr;
  }

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

  /* 步骤 */
  .step-item {
    grid-template-columns: 44px 1fr;
    gap: 16px;
  }

  .step-number {
    width: 40px;
    height: 40px;
    font-size: 18px;
  }

  /* 内容块 */
  .content-block {
    padding: 24px;
  }

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

  /* 返回顶部 */
  .back-to-top {
    bottom: 16px;
    right: 16px;
  }
}

/* ---------- 小屏 (≤480px) ---------- */
@media (max-width: 480px) {
  .brand-tagline {
    display: none;
  }

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

  .hero-copy h1 {
    font-size: 24px;
  }

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

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

  .list-item {
    padding: 16px;
  }

  .pick-item {
    padding: 16px;
  }

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

  .timeline-group {
    padding-left: 20px;
  }

  .timeline-year::before {
    left: -20px;
  }

  .error-code {
    font-size: 72px;
  }
}

/* ---------- 打印 ---------- */
@media print {
  .site-header,
  .site-footer,
  .sidebar,
  .sidebar-right,
  .sidebar-area,
  .back-to-top,
  .hero-cta,
  .channel-tags {
    display: none;
  }

  .site-main {
    padding: 0;
  }

  .layout-shell,
  .page-layout {
    grid-template-columns: 1fr;
  }

  .main-content {
    max-width: 100%;
  }
}