/* ============================================================
   base — 全局基础
   ============================================================ */
:root {
  --color-ink: #2c3e50;
  --color-ink-soft: #34495e;
  --color-accent: #1abc9c;
  --color-bg: #ecf0f1;
  --color-line: #bdc3c7;
  --color-white: #ffffff;
  --color-text: #3d4a5a;
  --color-muted: #6b7b8d;
  --radius: 8px;
  --container: 1200px;
  --header-h: 64px;
  --shadow: 0 1px 3px rgba(44, 62, 80, 0.08);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
  object-fit: cover;
}

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

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-weight: 700;
  color: var(--color-ink);
  line-height: 1.3;
}

/* ============================================================
   layout — 全站骨架
   ============================================================ */

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

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

.brand-logo {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-ink);
  letter-spacing: 0.02em;
  white-space: nowrap;
  flex-shrink: 0;
}

.brand-logo:hover {
  color: var(--color-accent);
}

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

.site-nav .nav-list a {
  display: block;
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 0.95rem;
  color: var(--color-ink-soft);
  font-weight: 500;
}

.site-nav .nav-list a:hover {
  color: var(--color-accent);
  background: rgba(26, 188, 156, 0.08);
}

.site-nav .nav-list a.is-current {
  color: var(--color-accent);
  background: rgba(26, 188, 156, 0.1);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
  align-items: center;
  justify-content: center;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-ink);
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* ---- 主内容区 ---- */
.site-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.inner-main {
  padding-top: 32px;
  padding-bottom: 64px;
}

/* ---- 页脚 ---- */
.site-footer {
  background: var(--color-ink);
  color: #a8b6c4;
  margin-top: 64px;
}

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

.footer-group h4 {
  color: var(--color-white);
  font-size: 1rem;
  margin-bottom: 16px;
  font-weight: 600;
}

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

.footer-group ul li a {
  color: #a8b6c4;
  font-size: 0.9rem;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 20px 24px;
  text-align: center;
  font-size: 0.85rem;
  color: #8a9aa8;
}

.footer-bottom p + p {
  margin-top: 4px;
}

/* ---- 面包屑 ---- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--color-muted);
  margin-bottom: 24px;
}

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

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

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

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

/* ---- 页面标题区 ---- */
.page-header {
  margin-bottom: 40px;
}

.page-title {
  font-size: 2rem;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.page-description {
  font-size: 1rem;
  color: var(--color-muted);
  max-width: 720px;
}

/* ---- 内页布局容器 ---- */
.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 40px;
  align-items: start;
}

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

/* 侧栏在左：此容器本身带 .sidebar-left，或祖先带 .sidebar-left */
.sidebar-left {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 40px;
  align-items: start;
}

.sidebar-left .guide-content,
.sidebar-left .content-area {
  min-width: 0;
}

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

/* ---- 侧栏卡片 ---- */
.sidebar-card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.sidebar-card h2 {
  font-size: 1.05rem;
  margin-bottom: 12px;
  color: var(--color-ink);
}

.sidebar-card p {
  font-size: 0.9rem;
  color: var(--color-muted);
  margin-bottom: 10px;
}

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

.sidebar-list li a {
  font-size: 0.9rem;
  color: var(--color-ink-soft);
  display: inline-block;
  line-height: 1.5;
}

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

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

.section-title {
  font-size: 1.5rem;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.section-intro {
  font-size: 0.95rem;
  color: var(--color-muted);
  margin-bottom: 24px;
  max-width: 640px;
}

/* ---- 按钮 ---- */
.btn-primary,
.btn-secondary,
.btn-home {
  display: inline-block;
  padding: 10px 24px;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-white);
  border: 1px solid var(--color-accent);
}

.btn-primary:hover {
  background: #16a085;
  color: var(--color-white);
}

.btn-secondary {
  background: transparent;
  color: var(--color-ink-soft);
  border: 1px solid var(--color-line);
}

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

.btn-home {
  background: var(--color-accent);
  color: var(--color-white);
  border: 1px solid var(--color-accent);
}

.btn-home:hover {
  background: #16a085;
  color: var(--color-white);
}

/* ---- 图片容器 ---- */
figure {
  margin: 0;
}

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

figcaption {
  font-size: 0.85rem;
  color: var(--color-muted);
  padding: 8px 4px 0;
}

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

/* ===================== 首页 ===================== */

/* 焦点报道 */
.hero-focus {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
  padding: 56px 0 48px;
}

.hero-copy h1 {
  font-size: 2.25rem;
  color: var(--color-ink);
  margin-bottom: 16px;
  line-height: 1.25;
}

.hero-copy p {
  font-size: 1.05rem;
  color: var(--color-muted);
  margin-bottom: 24px;
  max-width: 520px;
}

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

.hero-media {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

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

/* 频道导航带 */
.channel-strip {
  padding: 40px 0;
  border-top: 1px solid var(--color-line);
}

.channel-tags {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.tag-item {
  display: block;
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 14px 20px;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-ink-soft);
  text-align: center;
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.tag-item:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: rgba(26, 188, 156, 0.04);
}

/* 最新资讯 */
.latest-news {
  padding: 40px 0;
  border-top: 1px solid var(--color-line);
}

.news-list {
  display: grid;
  gap: 0;
}

.news-item {
  padding: 20px 0;
  border-bottom: 1px solid var(--color-line);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: baseline;
}

.news-item:first-child {
  border-top: 1px solid var(--color-line);
}

.news-item h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 4px;
}

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

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

.news-summary {
  font-size: 0.9rem;
  color: var(--color-muted);
  grid-column: 1;
}

.news-item time {
  font-size: 0.85rem;
  color: var(--color-muted);
  grid-column: 2;
  grid-row: 1;
  white-space: nowrap;
}

/* 专题推荐 */
.topic-recommend {
  padding: 40px 0;
  border-top: 1px solid var(--color-line);
}

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

.rec-card {
  display: block;
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.rec-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 12px rgba(44, 62, 80, 0.08);
}

.rec-card figure {
  height: 180px;
  overflow: hidden;
}

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

.rec-card h3 {
  font-size: 1.1rem;
  padding: 16px 20px 4px;
  color: var(--color-ink);
}

.rec-card p {
  font-size: 0.9rem;
  color: var(--color-muted);
  padding: 0 20px 20px;
}

/* 编辑推荐 */
.editor-picks {
  padding: 40px 0;
  border-top: 1px solid var(--color-line);
}

.pick-list {
  display: grid;
  gap: 16px;
}

.pick-item {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 16px;
  align-items: start;
  padding: 16px;
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}

.pick-tag {
  display: inline-block;
  background: rgba(26, 188, 156, 0.1);
  color: var(--color-accent);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 4px;
  text-align: center;
  white-space: nowrap;
}

.pick-item a {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-ink);
  display: inline-block;
  margin-bottom: 4px;
}

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

.pick-reason {
  font-size: 0.9rem;
  color: var(--color-muted);
  grid-column: 2;
}

/* 信息来源与反馈 */
.source-feedback {
  padding: 40px 0;
  border-top: 1px solid var(--color-line);
}

.source-text {
  font-size: 0.95rem;
  color: var(--color-muted);
  max-width: 760px;
  margin-bottom: 12px;
}

.feedback-note {
  font-size: 0.9rem;
  color: var(--color-muted);
}

/* ===================== 频道分类 ===================== */

.channel-index {
  margin-bottom: 48px;
}

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

.channel-card {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.channel-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 12px rgba(44, 62, 80, 0.08);
}

.channel-card-media {
  height: 140px;
  overflow: hidden;
}

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

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

.channel-card-body h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.channel-card-body h3 a {
  color: var(--color-ink);
}

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

.channel-card-body p {
  font-size: 0.9rem;
  color: var(--color-muted);
}

/* 频道详情列表 */
.channel-details {
  margin-bottom: 48px;
}

.channel-detail-list {
  display: grid;
  gap: 24px;
}

.channel-detail-item {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
}

.detail-text h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.detail-text p {
  font-size: 0.9rem;
  color: var(--color-muted);
}

/* 频道内容预览 */
.preview-list {
  display: grid;
  gap: 16px;
}

.preview-item {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 16px;
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 16px;
  align-items: start;
}

.preview-meta {
  grid-column: 1;
  grid-row: 1 / span 2;
}

.preview-meta img {
  width: 100px;
  height: 70px;
  object-fit: cover;
  border-radius: 4px;
}

.preview-item h3 {
  font-size: 1rem;
  font-weight: 600;
  grid-column: 2;
}

.preview-item h3 a {
  color: var(--color-ink);
}

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

.preview-item p {
  font-size: 0.88rem;
  color: var(--color-muted);
  grid-column: 2;
}

/* ===================== 内容专题 ===================== */

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

.topic-list {
  display: grid;
  gap: 24px;
}

.topic-item {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 24px;
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.topic-item:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 12px rgba(44, 62, 80, 0.08);
}

.topic-media {
  height: 100%;
  min-height: 160px;
}

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

.topic-content {
  padding: 20px 24px 20px 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.topic-content h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.topic-content h3 a {
  color: var(--color-ink);
}

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

.topic-content p {
  font-size: 0.92rem;
  color: var(--color-muted);
  margin-bottom: 12px;
}

.topic-content a {
  font-size: 0.9rem;
  font-weight: 500;
}

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

.topic-detail-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 32px;
  align-items: start;
}

.detail-feature {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 32px;
}

.detail-feature h3 {
  font-size: 1.3rem;
  margin-bottom: 12px;
}

.detail-feature p {
  font-size: 0.95rem;
  color: var(--color-muted);
  margin-bottom: 12px;
}

.detail-feature a {
  font-weight: 500;
}

.detail-sidebar {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
}

.detail-sidebar h3 {
  font-size: 1rem;
  margin-bottom: 16px;
}

.detail-sidebar ul li {
  margin-bottom: 10px;
}

.detail-sidebar ul li a {
  font-size: 0.9rem;
  color: var(--color-ink-soft);
}

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

/* ===================== 实用指南 ===================== */

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

.guide-section {
  margin-bottom: 48px;
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.guide-section h2 {
  font-size: 1.4rem;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.guide-section > p {
  font-size: 0.95rem;
  color: var(--color-muted);
  margin-bottom: 20px;
}

.guide-step {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 16px;
}

.guide-step h3 {
  font-size: 1.05rem;
  margin-bottom: 8px;
  color: var(--color-ink);
}

.guide-step p {
  font-size: 0.92rem;
  color: var(--color-muted);
}

.guide-figure {
  border-radius: var(--radius);
  overflow: hidden;
  margin: 24px 0;
  background: var(--color-white);
  border: 1px solid var(--color-line);
}

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

.guide-figure figcaption {
  padding: 12px 16px;
}

.check-list {
  margin-bottom: 20px;
}

.check-list li {
  position: relative;
  padding-left: 24px;
  font-size: 0.95rem;
  color: var(--color-text);
  margin-bottom: 12px;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
}

.check-list li strong {
  color: var(--color-ink);
}

.timeline-steps {
  counter-reset: timeline;
  margin-bottom: 20px;
}

.timeline-steps li {
  position: relative;
  padding-left: 40px;
  padding-bottom: 20px;
  font-size: 0.95rem;
  color: var(--color-text);
  counter-increment: timeline;
}

.timeline-steps li::before {
  content: counter(timeline);
  position: absolute;
  left: 0;
  top: 0;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--color-accent);
  color: var(--color-white);
  font-size: 0.8rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

.timeline-steps li::after {
  content: "";
  position: absolute;
  left: 13px;
  top: 30px;
  bottom: 0;
  width: 1px;
  background: var(--color-line);
}

.timeline-steps li:last-child::after {
  display: none;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 20px 0;
}

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

.tool-card h3 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.tool-card p {
  font-size: 0.88rem;
  color: var(--color-muted);
}

/* ===================== 深度解读 ===================== */

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

.insight-section {
  margin-bottom: 48px;
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.insight-section h2 {
  font-size: 1.4rem;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.insight-article {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 32px;
}

.article-media {
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 24px;
}

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

.article-media figcaption {
  padding: 10px 12px;
  background: var(--color-bg);
}

.article-lead {
  font-size: 1.05rem;
  color: var(--color-ink);
  font-weight: 500;
  margin-bottom: 16px;
  line-height: 1.8;
}

.insight-article p {
  font-size: 0.95rem;
  color: var(--color-text);
  margin-bottom: 16px;
}

.framework-list {
  margin: 16px 0;
}

.framework-list li {
  position: relative;
  padding-left: 24px;
  font-size: 0.95rem;
  color: var(--color-text);
  margin-bottom: 12px;
}

.framework-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--color-accent);
}

.framework-list li strong {
  color: var(--color-ink);
}

.source-note {
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
}

.source-note h2 {
  font-size: 1.1rem;
  margin-bottom: 12px;
}

.source-note p {
  font-size: 0.9rem;
  color: var(--color-muted);
  margin-bottom: 8px;
}

/* ===================== 404 ===================== */

.error-main {
  padding: 80px 24px;
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.error-content {
  text-align: center;
  margin-bottom: 48px;
}

.error-code {
  font-size: 5rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-content h1 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 1rem;
  color: var(--color-muted);
  margin-bottom: 24px;
}

.error-suggest {
  max-width: 480px;
  width: 100%;
}

.error-suggest h2 {
  font-size: 1.1rem;
  margin-bottom: 16px;
  text-align: center;
}

.error-suggest ul {
  display: grid;
  gap: 8px;
}

.error-suggest ul li {
  text-align: center;
}

.error-suggest ul li a {
  display: block;
  padding: 10px 16px;
  background: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: 6px;
  color: var(--color-ink-soft);
  font-size: 0.95rem;
}

.error-suggest ul li a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

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

@media (max-width: 1024px) {
  .page-layout {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 24px;
  }

  .sidebar-left {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 24px;
  }

  .topic-detail-layout {
    grid-template-columns: 1fr 240px;
    gap: 24px;
  }

  .hero-focus {
    gap: 32px;
  }

  .hero-copy h1 {
    font-size: 2rem;
  }
}

@media (max-width: 860px) {
  .header-inner {
    padding: 0 16px;
  }

  .site-main {
    padding: 0 16px;
  }

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

  .footer-bottom {
    padding: 16px;
  }

  /* 导航切换 */
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-line);
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.08);
  }

  .site-nav .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 12px 16px;
    gap: 4px;
  }

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

  .site-nav .nav-list a {
    padding: 12px 16px;
    border-radius: 6px;
  }

  /* 首页焦点区 */
  .hero-focus {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 40px 0 32px;
  }

  .hero-copy h1 {
    font-size: 1.75rem;
  }

  .hero-media img {
    height: 240px;
  }

  /* 频道标签 */
  .channel-tags {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .pick-item a {
    grid-column: 1;
  }

  .pick-reason {
    grid-column: 1;
  }

  /* 内页布局切换为单列 */
  .page-layout {
    grid-template-columns: 1fr;
  }

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

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

  /* 专题列表 */
  .topic-item {
    grid-template-columns: 1fr;
  }

  .topic-media {
    height: 200px;
  }

  .topic-content {
    padding: 0 20px 20px;
  }

  /* 专题详情 */
  .topic-detail-layout {
    grid-template-columns: 1fr;
  }

  /* 工具卡片 */
  .tool-grid {
    grid-template-columns: 1fr;
  }

  /* 侧栏顺序：内容优先，侧栏后置 */
  .sidebar-left .guide-sidebar,
  .sidebar-left .sidebar {
    order: 2;
  }

  .sidebar-left .guide-content,
  .sidebar-left .content-area {
    order: 1;
  }
}

@media (max-width: 560px) {
  .footer-links {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }

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

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

  .news-item {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .news-item time {
    grid-column: 1;
    grid-row: auto;
  }

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

  .preview-meta {
    grid-column: 1;
    grid-row: auto;
  }

  .preview-meta img {
    width: 100%;
    height: 140px;
  }

  .preview-item h3,
  .preview-item p {
    grid-column: 1;
  }

  .detail-feature {
    padding: 20px;
  }

  .insight-article {
    padding: 20px;
  }

  .page-title {
    font-size: 1.6rem;
  }

  .hero-copy h1 {
    font-size: 1.5rem;
  }

  .error-code {
    font-size: 3.5rem;
  }
}

@media (max-width: 390px) {
  .footer-links {
    grid-template-columns: 1fr;
  }

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

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-secondary {
    text-align: center;
  }

  .guide-step {
    padding: 16px;
  }

  .tool-card {
    padding: 16px;
  }
}