/* ==========================================================================
  51吃瓜玩偶姐姐 - 全站样式表
  档案馆风：索引编号、日期分组、缩略图统一、历史感克制
  ========================================================================== */

/* --------------------------------------------------------------------------
  Base
  -------------------------------------------------------------------------- */
:root {
  --color-primary: #2c3e50;
  --color-primary-light: #34495e;
  --color-bg: #ecf0f1;
  --color-border: #bdc3c7;
  --color-accent: #e67e22;
  --color-text: #2c3e50;
  --color-text-light: #5d6d7e;
  --color-white: #ffffff;
  --font-serif: "Songti SC", "SimSun", "STSong", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --container-width: 1200px;
  --radius: 6px;
  --transition: 0.25s ease;
}

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

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

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

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

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

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-serif);
  line-height: 1.3;
  color: var(--color-primary);
}

h1 {
  font-size: 32px;
  font-weight: 700;
}

h2 {
  font-size: 24px;
  font-weight: 700;
}

h3 {
  font-size: 18px;
  font-weight: 600;
}

h4 {
  font-size: 16px;
  font-weight: 600;
}

p {
  margin-bottom: 1em;
}

strong {
  font-weight: 600;
}

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

.site-header {
  background-color: var(--color-primary);
  border-bottom: 3px solid var(--color-accent);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  min-height: 72px;
}

.brand-logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-decoration: none;
  padding: 10px 0;
}

.brand-name {
  font-family: var(--font-serif);
  font-size: 24px;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 2px;
}

.brand-slogan {
  font-size: 12px;
  color: var(--color-border);
  letter-spacing: 4px;
}

.site-nav {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  bottom: 0;
}

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

.nav-list li {
  position: relative;
}

.nav-list a {
  display: block;
  padding: 14px 18px;
  color: var(--color-border);
  font-size: 15px;
  border-bottom: 3px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}

.nav-list a:hover {
  color: var(--color-white);
  border-bottom-color: var(--color-accent);
}

.nav-list a.is-current {
  color: var(--color-white);
  border-bottom-color: var(--color-accent);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
}

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

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

.home-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px 20px 60px;
}

.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px 20px 60px;
}

.site-footer {
  background-color: var(--color-primary);
  color: var(--color-border);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px 20px 24px;
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 40px;
}

.footer-brand {
  padding-right: 20px;
}

.footer-logo {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-white);
  display: inline-block;
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 14px;
  line-height: 1.8;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.link-group h4 {
  color: var(--color-white);
  font-size: 15px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

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

.link-group a {
  color: var(--color-border);
  font-size: 14px;
}

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

.footer-bottom {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 16px 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
}

.footer-bottom p {
  margin-bottom: 0;
}

/* --------------------------------------------------------------------------
  Components
  -------------------------------------------------------------------------- */
.section-title {
  font-size: 22px;
  margin-bottom: 24px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-accent);
  position: relative;
}

.section-title::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background-color: var(--color-accent);
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
}

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

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

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

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

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

.page-title {
  margin-bottom: 8px;
}

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

/* 首页 Hero */
.hero-section {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 40px;
  align-items: center;
  margin-bottom: 48px;
  padding: 32px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.hero-copy h1 {
  font-size: 32px;
  margin-bottom: 16px;
  line-height: 1.3;
}

.hero-lead {
  font-size: 16px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 24px;
}

.hero-cta {
  display: inline-block;
  padding: 10px 28px;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  transition: background-color var(--transition);
}

.hero-cta:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.hero-media {
  margin-bottom: 0;
}

.hero-media img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  border-radius: var(--radius);
}

/* 频道标签带 */
.channel-nav-section {
  margin-bottom: 48px;
}

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

.channel-tag {
  display: inline-block;
  padding: 8px 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  font-size: 14px;
  color: var(--color-primary);
  transition: background-color var(--transition), color var(--transition),
    border-color var(--transition);
}

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

/* 最新动态列表 */
.latest-list-section {
  margin-bottom: 48px;
}

.date-group {
  margin-bottom: 24px;
}

.date-label {
  font-size: 16px;
  color: var(--color-text-light);
  margin-bottom: 12px;
  padding-left: 12px;
  border-left: 3px solid var(--color-accent);
}

.news-list li {
  border-bottom: 1px solid var(--color-border);
}

.news-list a {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
}

.news-time {
  font-size: 13px;
  color: var(--color-text-light);
  min-width: 80px;
  font-family: var(--font-serif);
}

.news-text {
  font-size: 15px;
  color: var(--color-text);
  transition: color var(--transition);
}

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

/* 专题推荐 */
.topic-recommend-section {
  margin-bottom: 48px;
}

.topic-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.topic-card {
  display: flex;
  flex-direction: column;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition);
}

.topic-card:hover {
  box-shadow: 0 4px 16px rgba(44, 62, 80, 0.12);
  transform: translateY(-2px);
}

.card-thumb {
  margin-bottom: 0;
}

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

.card-body {
  padding: 20px;
}

.card-body h3 {
  margin-bottom: 8px;
}

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

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

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

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

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

.pick-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 16px 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: box-shadow var(--transition);
}

.pick-item:hover {
  box-shadow: 0 2px 12px rgba(44, 62, 80, 0.1);
}

.pick-index {
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  min-width: 40px;
}

.pick-content h3 {
  margin-bottom: 4px;
}

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

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

.pick-content p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* 来源与反馈 */
.source-feedback-section {
  margin-bottom: 0;
  padding: 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.source-desc,
.feedback-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 8px;
}

.source-desc:last-child,
.feedback-desc:last-child {
  margin-bottom: 0;
}

/* --------------------------------------------------------------------------
  频道分类页
  -------------------------------------------------------------------------- */
.filter-desc {
  margin-bottom: 32px;
  padding: 20px 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.filter-desc p {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 0;
}

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

.channel-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.channel-card {
  display: flex;
  flex-direction: column;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition);
}

.channel-card:hover {
  box-shadow: 0 4px 16px rgba(44, 62, 80, 0.12);
  transform: translateY(-2px);
}

.channel-media {
  margin-bottom: 0;
}

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

.channel-content {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.channel-name {
  margin-bottom: 8px;
}

.channel-desc {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 16px;
  flex: 1;
}

.channel-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

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

/* 频道简介 */
.channel-intro {
  margin-bottom: 40px;
}

.intro-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.intro-item {
  padding: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  text-align: center;
}

.intro-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.intro-item p {
  font-size: 13px;
  color: var(--color-text-light);
  margin-bottom: 0;
  line-height: 1.6;
}

/* 分页 */
.pagination {
  margin: 32px 0;
  text-align: center;
}

.pagination p {
  display: inline-block;
  padding: 8px 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* 频道页来源说明 */
.source-feedback {
  padding: 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.source-feedback p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 8px;
}

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

/* --------------------------------------------------------------------------
  内容专题页
  -------------------------------------------------------------------------- */
.topic-grid {
  margin-bottom: 40px;
}

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

.topic-media {
  margin-bottom: 0;
}

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

.topic-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.topic-tag {
  display: inline-block;
  align-self: flex-start;
  padding: 2px 12px;
  background-color: rgba(230, 126, 34, 0.12);
  color: var(--color-accent);
  font-size: 12px;
  border-radius: 12px;
  margin-bottom: 10px;
}

.topic-body h3 {
  margin-bottom: 8px;
}

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

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

.topic-body p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 16px;
  flex: 1;
}

.topic-body a {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

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

/* 专题摘要 */
.topic-summary {
  margin-bottom: 0;
}

.summary-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

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

.summary-item h3 {
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

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

/* --------------------------------------------------------------------------
  实用指南页
  -------------------------------------------------------------------------- */
.guide-content {
  max-width: 860px;
}

.guide-lead {
  margin-bottom: 32px;
}

.guide-lead p {
  font-size: 16px;
  color: var(--color-text-light);
  margin-bottom: 16px;
}

.guide-figure {
  margin-bottom: 0;
}

.guide-figure img {
  width: 100%;
  height: 280px;
  object-fit: cover;
  border-radius: var(--radius);
}

.guide-figure figcaption {
  font-size: 13px;
  color: var(--color-text-light);
  padding: 8px 0;
  text-align: center;
}

.guide-content > h2 {
  margin: 32px 0 16px;
  font-size: 22px;
}

.guide-content > p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
}

.guide-list,
.guide-steps {
  margin: 16px 0 24px;
  padding-left: 24px;
}

.guide-list {
  list-style: disc;
}

.guide-list li {
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 8px;
  padding-left: 4px;
}

.guide-list strong {
  color: var(--color-primary);
}

.guide-steps {
  list-style: decimal;
  counter-reset: step;
}

.guide-steps li {
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 12px;
  padding-left: 4px;
}

.guide-steps strong {
  color: var(--color-primary);
}

.guide-steps a {
  color: var(--color-accent);
}

.guide-steps a:hover {
  color: var(--color-primary);
}

/* --------------------------------------------------------------------------
  时间线页
  -------------------------------------------------------------------------- */
.page-layout.sidebar-left {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 32px;
  align-items: start;
}

.page-sidebar {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  position: sticky;
  top: 96px;
}

.sidebar-section {
  margin-bottom: 24px;
}

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

.sidebar-title {
  font-size: 16px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.sidebar-section p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 8px;
}

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

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

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

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

/* 时间线简介 */
.timeline-intro {
  margin-bottom: 32px;
  padding: 20px 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.timeline-intro p {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 0;
}

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

.timeline-intro a:hover {
  color: var(--color-primary);
}

/* 时间线主体 */
.timeline-section {
  margin-bottom: 40px;
}

.timeline-list {
  position: relative;
  padding-left: 24px;
}

.timeline-list::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background-color: var(--color-border);
}

.timeline-item {
  position: relative;
  margin-bottom: 24px;
  padding: 20px 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 24px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 2px solid var(--color-white);
  box-shadow: 0 0 0 2px var(--color-accent);
}

.timeline-date {
  font-family: var(--font-serif);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.timeline-title {
  font-size: 16px;
  margin-bottom: 8px;
}

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

.timeline-body p {
  margin-bottom: 0;
}

/* 时间线节点 */
.timeline-nodes {
  margin-bottom: 0;
}

.nodes-content {
  padding: 24px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.nodes-content > p {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 16px;
}

.nodes-content > p a {
  color: var(--color-accent);
}

.nodes-content > p a:hover {
  color: var(--color-primary);
}

.timeline-figure {
  margin: 16px 0;
}

.timeline-figure img {
  width: 100%;
  height: 240px;
  object-fit: cover;
  border-radius: var(--radius);
}

.timeline-figure figcaption {
  font-size: 13px;
  color: var(--color-text-light);
  padding: 8px 0;
  text-align: center;
}

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

.node-list li {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 8px;
  padding-left: 16px;
  position: relative;
}

.node-list li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--color-accent);
  font-weight: 700;
}

/* --------------------------------------------------------------------------
  404 页
  -------------------------------------------------------------------------- */
.error-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 20px;
}

.error-section {
  text-align: center;
  max-width: 560px;
  padding: 48px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

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

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

.error-desc {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 8px;
}

.error-tip {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.error-back {
  display: inline-block;
  padding: 10px 32px;
  background-color: var(--color-primary);
  color: var(--color-white);
  font-size: 15px;
  border-radius: var(--radius);
  transition: background-color var(--transition);
}

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

/* --------------------------------------------------------------------------
  Responsive
  -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .channel-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .intro-grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

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

  .footer-brand {
    padding-right: 0;
  }
}

@media (max-width: 768px) {
  h1 {
    font-size: 26px;
  }

  h2 {
    font-size: 20px;
  }

  .header-inner {
    min-height: 60px;
    justify-content: flex-start;
    padding: 0 16px;
  }

  .brand-logo {
    align-items: flex-start;
  }

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

  .brand-slogan {
    font-size: 11px;
    letter-spacing: 2px;
  }

  .nav-toggle {
    display: flex;
    right: 16px;
    z-index: 10;
  }

  .nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .site-nav {
    position: fixed;
    left: 0;
    top: 60px;
    width: 100%;
    transform: none;
    background-color: var(--color-primary);
    border-bottom: 3px solid var(--color-accent);
    z-index: 99;
  }

  .nav-list {
    flex-direction: column;
    display: none;
    padding: 8px 0;
  }

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

  .nav-list a {
    padding: 14px 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    border-left: 3px solid transparent;
  }

  .nav-list a.is-current {
    border-left-color: var(--color-accent);
    border-bottom-color: rgba(255, 255, 255, 0.08);
  }

  .home-main {
    padding: 24px 16px 48px;
  }

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

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

  .hero-media img {
    height: 220px;
  }

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

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

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

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

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

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

  .footer-bottom {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }

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

  .page-sidebar {
    position: static;
    order: 2;
  }

  .page-content {
    order: 1;
  }

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

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

  .error-section {
    padding: 32px 24px;
  }

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

@media (max-width: 480px) {
  .intro-grid {
    grid-template-columns: 1fr;
  }

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

  .channel-tags {
    gap: 8px;
  }

  .channel-tag {
    padding: 6px 16px;
    font-size: 13px;
  }

  .news-list a {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .news-time {
    min-width: 0;
  }

  .pick-item {
    gap: 12px;
    padding: 14px 16px;
  }

  .pick-index {
    font-size: 24px;
    min-width: 32px;
  }

  .timeline-item {
    padding: 16px;
  }

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

  .timeline-item::before {
    left: -25px;
  }
}