/* ==========================================================================
   吃瓜网在线 - 全站样式表
   版本: 1.0
   说明: 本样式表服务于全站五个页面 + 404页，严格遵循 DOM 结构编写。
   ========================================================================== */

/* ==========================================================================
   1. Base - 基础重置与全局变量
   ========================================================================== */

:root {
  --color-black: #000000;
  --color-white: #ffffff;
  --color-accent: #f5a623;
  --color-text: #333333;
  --color-bg-light: #f8f8f8;
  --color-border: #e5e5e5;
  --color-text-light: #666666;
  --color-text-muted: #999999;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;

  --container-width: 1200px;
  --container-padding: 0 24px;
  --header-height: 72px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --transition-base: 0.2s ease;

  --content-max-width: 760px;
  --sidebar-width: 300px;
}

*,
*::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-family);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-text);
  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-weight: 700;
  line-height: 1.3;
  color: var(--color-black);
}

/* ==========================================================================
   2. Layout - 全局布局骨架
   ========================================================================== */

.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

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

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

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

.brand-name {
  font-size: 22px;
  font-weight: 800;
  color: var(--color-black);
  letter-spacing: 0.5px;
}

.brand-slogan {
  font-size: 12px;
  color: var(--color-text-muted);
  letter-spacing: 0.2px;
}

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

.nav-list {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-list li a {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  padding: 8px 0;
  position: relative;
  display: block;
}

.nav-list li a:hover {
  color: var(--color-accent);
}

.nav-list li a.is-current {
  color: var(--color-accent);
}

.nav-list li a.is-current::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background-color: var(--color-accent);
}

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

.nav-toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-black);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

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

.site-footer {
  background-color: var(--color-bg-light);
  border-top: 1px solid var(--color-border);
  margin-top: 64px;
}

.footer-columns {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px 32px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.footer-heading {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
}

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

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

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

.footer-bottom {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 20px 24px 32px;
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-brand {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
}

.copyright {
  font-size: 13px;
  color: var(--color-text-muted);
}

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

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

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

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

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

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

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

.page-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--color-black);
  margin-bottom: 12px;
}

.page-description {
  font-size: 16px;
  color: var(--color-text-light);
  max-width: 640px;
  line-height: 1.7;
}

/* 区块标题 */
.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
  position: relative;
  padding-left: 14px;
}

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

.section-lead {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 24px;
  max-width: 640px;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-base),
    color var(--transition-base), border-color var(--transition-base);
  min-height: 44px;
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-white);
}

.btn-primary:hover {
  background-color: #e09517;
  color: var(--color-white);
}

.btn-secondary {
  background-color: var(--color-white);
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* 图片容器 */
figure {
  margin: 0;
}

/* 滚动出现动画（渐进增强，不阻塞初始可见性） */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==========================================================================
   4. Pages - 页面专属样式
   ========================================================================== */

/* ---------------- 4.1 首页 index.html ---------------- */

.home-main {
  width: 100%;
}

/* 首屏焦点区 */
.hero-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 56px 24px;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 48px;
  align-items: center;
}

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

.hero-title {
  font-size: 38px;
  font-weight: 800;
  line-height: 1.25;
  color: var(--color-black);
}

.hero-description {
  font-size: 16px;
  color: var(--color-text-light);
  line-height: 1.8;
  max-width: 480px;
}

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

.hero-media {
  display: flex;
  justify-content: center;
}

.hero-figure {
  width: 100%;
  max-width: 520px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-bg-light);
  aspect-ratio: 4 / 3;
}

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

/* 频道分类导航带 */
.channel-nav-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px;
  border-top: 1px solid var(--color-border);
}

.channel-tag-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.channel-tag {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px 24px;
  background-color: var(--color-bg-light);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  transition: all var(--transition-base);
  min-height: 48px;
}

.channel-tag:hover {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-white);
}

/* 最新资讯列表 */
.latest-news-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px;
  border-top: 1px solid var(--color-border);
}

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

.news-item {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "title date"
    "summary date";
  gap: 4px 24px;
  padding: 20px 24px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  border-left: 3px solid transparent;
  transition: border-color var(--transition-base);
}

.news-item:hover {
  border-left-color: var(--color-accent);
}

.news-title {
  grid-area: title;
  font-size: 17px;
  font-weight: 600;
}

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

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

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

.news-date {
  grid-area: date;
  font-size: 13px;
  color: var(--color-text-muted);
  white-space: nowrap;
  align-self: start;
  padding-top: 4px;
}

/* 专题推荐区 */
.topic-cards-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px;
  border-top: 1px solid var(--color-border);
}

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

.topic-card {
  background-color: var(--color-white);
  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: 0 4px 16px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.topic-card-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background-color: var(--color-bg-light);
}

.topic-card-title {
  font-size: 18px;
  font-weight: 700;
  padding: 16px 20px 8px;
}

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

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

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

/* 编辑推荐 */
.editor-picks-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px;
  border-top: 1px solid var(--color-border);
}

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

.editor-pick-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px 16px;
  padding: 16px 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  align-items: start;
}

.editor-pick-item::before {
  content: "推荐";
  display: inline-block;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 12px;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  line-height: 1.4;
  margin-top: 2px;
}

.editor-pick-title {
  font-size: 16px;
  font-weight: 600;
  grid-column: 2;
}

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

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

.editor-pick-reason {
  grid-column: 2;
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.6;
}

/* 信息来源与反馈 */
.source-feedback-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 24px;
  border-top: 1px solid var(--color-border);
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
  margin-top: 48px;
}

.feedback-text {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 16px;
  max-width: 640px;
}

.feedback-link {
  display: inline-flex;
  align-items: center;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-accent);
  border-bottom: 2px solid var(--color-accent);
  padding-bottom: 2px;
}

.feedback-link:hover {
  color: var(--color-black);
  border-bottom-color: var(--color-black);
}

/* ---------------- 4.2 频道分类页 cgwzx/channels.html ---------------- */

.page-channels {
  background-color: var(--color-white);
}

.page-layout {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px 24px;
  display: grid;
  grid-template-columns: 1fr var(--sidebar-width);
  gap: 48px;
  align-items: start;
}

.inner-main {
  min-width: 0;
  width: 100%;
}

.channel-list-section {
  margin-bottom: 40px;
}

.channel-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.channel-item {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 24px;
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: box-shadow var(--transition-base);
}

.channel-item:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

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

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

.channel-content {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.channel-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-black);
}

.channel-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  flex: 1;
}

.channel-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  align-self: flex-start;
}

.channel-link:hover {
  color: var(--color-black);
}

.channel-summary-section {
  margin-bottom: 40px;
  padding: 24px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
}

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

.summary-text:last-child {
  margin-bottom: 0;
}

.related-pages {
  margin-bottom: 0;
}

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

.related-link-card {
  display: block;
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  transition: all var(--transition-base);
  min-height: 44px;
}

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

/* 侧栏 - 相关推荐 */
.sidebar-related {
  min-width: 0;
}

.sidebar-inner {
  position: sticky;
  top: calc(var(--header-height) + 24px);
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.sidebar-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-accent);
}

.sidebar-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.sidebar-list li a {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.5;
  display: block;
  padding: 4px 0;
}

.sidebar-list li a:hover {
  color: var(--color-accent);
}

.sidebar-text {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
}

.sidebar-text span {
  color: var(--color-text);
  font-weight: 600;
}

/* ---------------- 4.3 内容专题页 cgwzx/topics.html ---------------- */

.page-topics {
  background-color: var(--color-white);
}

.topic-intro {
  margin-bottom: 40px;
}

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

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

.topic-list {
  margin-bottom: 40px;
}

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

.topic-card-link {
  display: block;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition-base),
    transform var(--transition-base);
  height: 100%;
}

.topic-card-link:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.topic-cover {
  background-color: var(--color-bg-light);
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

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

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

.topic-card-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 8px;
}

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

.topic-card-summary {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.6;
  margin-bottom: 12px;
}

.topic-card-meta {
  font-size: 13px;
  color: var(--color-text-muted);
}

.topic-summary {
  margin-bottom: 40px;
  padding: 24px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
}

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

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

.related-topics {
  margin-bottom: 0;
}

.related-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-accent);
}

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

.related-list li a {
  font-size: 14px;
  color: var(--color-text-light);
  display: block;
  padding: 8px 12px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
}

.related-list li a:hover {
  color: var(--color-accent);
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
}

/* ---------------- 4.4 实用指南页 cgwzx/guide.html ---------------- */

.page-guide {
  background-color: var(--color-white);
}

.main-content {
  min-width: 0;
  width: 100%;
}

.guide-list {
  margin-bottom: 40px;
}

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

.guide-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

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

.guide-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.guide-card-img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background-color: var(--color-bg-light);
}

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

.guide-card-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 8px;
}

.guide-card-link {
  color: var(--color-black);
}

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

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

.guide-steps {
  margin-bottom: 40px;
}

.step-block {
  padding: 24px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
  border-left: 4px solid var(--color-accent);
}

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

.step-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 8px;
}

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

.step-list {
  padding-left: 20px;
  margin-bottom: 16px;
}

.step-list li {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 8px;
  padding-left: 8px;
  position: relative;
}

.step-list li::before {
  content: "";
  position: absolute;
  left: -12px;
  top: 10px;
  width: 6px;
  height: 6px;
  background-color: var(--color-accent);
  border-radius: 50%;
}

.step-tip {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.6;
  padding: 12px 16px;
  background-color: var(--color-white);
  border-radius: var(--radius-sm);
  border: 1px dashed var(--color-border);
}

.related-guides {
  margin-bottom: 0;
}

.related-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.related-links li a {
  display: block;
  padding: 12px 16px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--color-text);
  transition: all var(--transition-base);
}

.related-links li a:hover {
  color: var(--color-accent);
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
}

/* 侧栏 - 相关推荐 */
.sidebar {
  min-width: 0;
}

.sidebar-block {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 24px;
}

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

.sidebar-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-accent);
}

.sidebar-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.sidebar-links li a {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.5;
  display: block;
  padding: 4px 0;
}

.sidebar-links li a:hover {
  color: var(--color-accent);
}

/* ---------------- 4.5 深度解读页 cgwzx/insight.html ---------------- */

.page-insight {
  background-color: var(--color-white);
}

.insight-list {
  margin-bottom: 40px;
}

.insight-item {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 24px;
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
  transition: box-shadow var(--transition-base);
}

.insight-item:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

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

.insight-media {
  overflow: hidden;
  border-radius: var(--radius-md);
  background-color: var(--color-bg-light);
  aspect-ratio: 4 / 3;
}

.insight-media figure {
  width: 100%;
  height: 100%;
}

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

.insight-content {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.insight-content h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-black);
}

.insight-meta {
  font-size: 13px;
  color: var(--color-text-muted);
}

.insight-content p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
}

.analysis-framework {
  margin-bottom: 40px;
  padding: 24px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
}

.analysis-framework > p {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 20px;
}

.framework-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.framework-card {
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

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

.framework-card p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 0;
}

.framework-note {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-top: 16px;
  padding: 12px 16px;
  background-color: var(--color-white);
  border-radius: var(--radius-sm);
  border: 1px dashed var(--color-border);
}

.related-links {
  margin-bottom: 0;
}

.related-links h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
}

.related-links ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.related-links ul li a {
  display: block;
  padding: 12px 16px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--color-text);
  transition: all var(--transition-base);
}

.related-links ul li a:hover {
  color: var(--color-accent);
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
}

/* 侧栏 - 相关解读 */
.insight-sidebar {
  min-width: 0;
}

.sidebar-card {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 24px;
}

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

.sidebar-card h2 {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-accent);
}

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

.sidebar-list li a {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.5;
  display: block;
  padding: 4px 0;
}

.sidebar-list li a:hover {
  color: var(--color-accent);
}

/* ---------------- 4.6 404页 404.html ---------------- */

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

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

.error-section {
  text-align: center;
  max-width: 560px;
  width: 100%;
}

.error-code {
  font-size: 96px;
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-black);
  margin-bottom: 16px;
}

.error-desc {
  font-size: 16px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 32px;
}

.error-home-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  min-height: 44px;
  transition: background-color var(--transition-base);
}

.error-home-btn:hover {
  background-color: #e09517;
  color: var(--color-white);
}

.error-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 24px;
  margin-top: 32px;
}

.error-links a {
  font-size: 14px;
  color: var(--color-text-light);
}

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

/* ==========================================================================
   5. Responsive - 响应式适配
   ========================================================================== */

/* 平板及以下 */
@media (max-width: 992px) {
  .hero-section {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 40px 24px;
  }

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

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

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

  .page-layout {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .sidebar-related,
  .sidebar,
  .insight-sidebar {
    grid-row: auto;
  }

  .sidebar-inner {
    position: static;
  }

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

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

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

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

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

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

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

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

/* 手机端 */
@media (max-width: 768px) {
  :root {
    --header-height: 60px;
  }

  .header-container {
    padding: 0 16px;
    height: var(--header-height);
  }

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

  .brand-slogan {
    font-size: 10px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
    display: flex;
    visibility: hidden;
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity 0.25s ease, transform 0.25s ease,
      visibility 0.25s ease;
  }

  .site-nav.is-open {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
    padding: 16px;
    gap: 0;
  }

  .nav-list li a {
    padding: 14px 12px;
    font-size: 16px;
    border-bottom: 1px solid var(--color-border);
  }

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

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

  .nav-list li a.is-current {
    color: var(--color-accent);
    background-color: rgba(245, 166, 35, 0.08);
  }

  .hero-section {
    padding: 32px 16px;
    gap: 24px;
  }

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

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

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

  .btn {
    width: 100%;
  }

  .channel-nav-section,
  .latest-news-section,
  .topic-cards-section,
  .editor-picks-section,
  .source-feedback-section {
    padding: 32px 16px;
  }

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

  .news-item {
    grid-template-columns: 1fr;
    grid-template-areas:
      "title"
      "summary"
      "date";
    gap: 8px;
    padding: 16px;
  }

  .news-date {
    white-space: normal;
  }

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

  .editor-pick-item {
    grid-template-columns: 1fr;
    padding: 16px;
  }

  .editor-pick-item::before {
    justify-self: start;
  }

  .editor-pick-title,
  .editor-pick-reason {
    grid-column: 1;
  }

  .page-layout {
    padding: 24px 16px;
    grid-template-columns: 1fr;
    gap: 24px;
  }

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

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

  .page-description {
    font-size: 15px;
  }

  .section-title {
    font-size: 19px;
  }

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

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

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

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    padding: 16px;
    gap: 8px;
  }

  .breadcrumb {
    font-size: 13px;
    margin-bottom: 16px;
  }

  .step-block {
    padding: 20px 16px;
  }

  .step-list {
    padding-left: 16px;
  }

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

  .error-code {
    font-size: 64px;
  }

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

  .error-links {
    gap: 16px;
  }

  .insight-item {
    padding: 16px;
  }

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

  .sidebar-block,
  .sidebar-card,
  .sidebar-inner {
    padding: 20px 16px;
  }

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

/* 小屏手机 */
@media (max-width: 390px) {
  .hero-title {
    font-size: 24px;
  }

  .hero-description {
    font-size: 14px;
  }

  .channel-tag {
    padding: 14px 16px;
    font-size: 14px;
  }

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

  .news-summary {
    font-size: 13px;
  }

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

  .topic-card-excerpt {
    font-size: 13px;
  }

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

  .page-description {
    font-size: 14px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

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

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

/* ==========================================================================
   6. 打印样式（可选增强）
   ========================================================================== */

@media print {
  .site-header,
  .site-footer,
  .nav-toggle,
  .sidebar-related,
  .sidebar,
  .insight-sidebar,
  .breadcrumb {
    display: none !important;
  }

  .site-main {
    padding: 0;
  }

  .page-layout {
    display: block;
  }

  body {
    background-color: var(--color-white);
    color: var(--color-black);
  }
}