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

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #1F2937;
  background: #F9FAFB;
}

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

a {
  color: #2C6E91;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #1f5573;
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-weight: 600;
  line-height: 1.3;
  color: #1F2937;
}

h1 {
  font-size: 28px;
}

h2 {
  font-size: 22px;
}

h3 {
  font-size: 18px;
}

p {
  line-height: 1.7;
}

/* ============================================================
   layout
   ============================================================ */
.site-header {
  background: #FFFFFF;
  border-bottom: 1px solid #E5E7EB;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-link {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  color: #2C6E91;
  letter-spacing: 0.5px;
}

.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: 22px;
  height: 2px;
  background: #2C6E91;
  border-radius: 2px;
}

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

.site-nav .nav-list a {
  display: block;
  font-size: 15px;
  color: #374151;
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
  line-height: 1.4;
}

.site-nav .nav-list a:hover {
  color: #2C6E91;
}

.site-nav .nav-list a.is-current {
  color: #2C6E91;
  border-bottom-color: #2C6E91;
}

.site-main {
  min-height: 60vh;
}

.site-main.inner-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.site-footer {
  background: #FFFFFF;
  border-top: 1px solid #E5E7EB;
  margin-top: 60px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px 32px;
}

.footer-brand {
  margin-bottom: 24px;
}

.footer-brand-name {
  font-size: 18px;
  font-weight: 700;
  color: #2C6E91;
}

.footer-brand p {
  font-size: 13px;
  color: #6B7280;
  margin-top: 6px;
  max-width: 560px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  margin-bottom: 24px;
}

.footer-links a {
  font-size: 14px;
  color: #4B5563;
}

.footer-links a:hover {
  color: #2C6E91;
}

.footer-meta p {
  font-size: 13px;
  color: #9CA3AF;
  line-height: 1.6;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 0;
  font-size: 14px;
  color: #6B7280;
}

.breadcrumb a {
  color: #2C6E91;
}

.breadcrumb a:hover {
  color: #1f5573;
}

.breadcrumb-sep {
  color: #9CA3AF;
}

.breadcrumb-current {
  color: #6B7280;
}

/* 页面标题区 */
.page-header {
  padding: 8px 0 20px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: #1F2937;
  margin-bottom: 8px;
}

.page-description {
  font-size: 16px;
  color: #6B7280;
  max-width: 760px;
}

/* 限制提示条 */
.limitation-notice {
  background: #F3F4F6;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  padding: 12px 16px;
  margin-bottom: 32px;
}

.limitation-notice p {
  font-size: 14px;
  color: #6B7280;
  line-height: 1.6;
}

/* ============================================================
   components
   ============================================================ */
/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 500;
  line-height: 1.4;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
  min-height: 44px;
}

.btn-primary {
  background: #2C6E91;
  color: #FFFFFF;
}

.btn-primary:hover {
  background: #245a78;
  color: #FFFFFF;
}

.btn-secondary {
  background: #EAF4FA;
  color: #2C6E91;
  border: 1px solid #d0e6f2;
}

.btn-secondary:hover {
  background: #d9ebf5;
  color: #245a78;
}

/* 模块标题 */
.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
}

.section-head h2 {
  font-size: 22px;
  font-weight: 700;
  color: #1F2937;
}

.section-head p {
  font-size: 14px;
  color: #6B7280;
  margin-top: 4px;
}

.section-more {
  font-size: 14px;
  color: #2C6E91;
  white-space: nowrap;
  flex-shrink: 0;
}

.section-more:hover {
  color: #1f5573;
}

/* 胶囊标签 */
.tag-chip {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  border-radius: 999px;
  background: #EAF4FA;
  color: #2C6E91;
  font-size: 14px;
  border: 1px solid transparent;
  transition: background 0.2s ease, border-color 0.2s ease;
  min-height: 44px;
}

.tag-chip:hover {
  background: #d9ebf5;
  border-color: #b8d9ec;
  color: #245a73;
}

/* 封面卡 */
.update-card {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.update-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.06);
}

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

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

.card-tag {
  display: inline-block;
  background: #EAF4FA;
  color: #2C6E91;
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
}

.card-body p {
  font-size: 14px;
  color: #4B5563;
  line-height: 1.6;
}

/* 图文媒体 */
.content-media {
  margin: 16px 0;
}

.content-media img {
  width: 100%;
  height: auto;
  border-radius: 8px;
}

.content-media figcaption {
  font-size: 13px;
  color: #9CA3AF;
  margin-top: 8px;
  line-height: 1.5;
}

.content-media-inline {
  margin: 20px 0;
  max-width: 640px;
}

/* FAQ 手风琴 */
.faq-item {
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  background: #FFFFFF;
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-item summary {
  padding: 14px 18px;
  font-size: 15px;
  font-weight: 500;
  color: #1F2937;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 44px;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  color: #2C6E91;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item summary:hover {
  background: #F9FAFB;
}

.faq-item p {
  padding: 0 18px 16px;
  font-size: 14px;
  color: #4B5563;
  line-height: 1.7;
}

/* 相关链接 */
.related-links {
  margin-top: 48px;
  padding: 20px 0;
  border-top: 1px solid #E5E7EB;
}

.related-links-label {
  font-size: 14px;
  font-weight: 600;
  color: #1F2937;
  margin-right: 16px;
}

.related-links-item {
  font-size: 14px;
  color: #2C6E91;
  margin-right: 16px;
}

.related-links-item:hover {
  color: #1f5573;
}

/* ============================================================
   pages · index
   ============================================================ */
.hero-section {
  background: #FFFFFF;
  border-bottom: 1px solid #E5E7EB;
}

.hero-section {
  display: flex;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 56px 20px 48px;
  gap: 48px;
}

.hero-content {
  flex: 1 1 55%;
}

.hero-title {
  font-size: 32px;
  font-weight: 700;
  color: #1F2937;
  line-height: 1.3;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 16px;
  color: #6B7280;
  line-height: 1.7;
  margin-bottom: 28px;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-figure {
  flex: 1 1 45%;
}

.hero-figure img {
  width: 100%;
  height: auto;
  border-radius: 8px;
}

/* 热门题材 */
.hot-tags-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 20px 0;
}

.tag-wall {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* 最近更新 */
.recent-updates-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 20px 0;
}

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

/* 人气榜单 */
.rankings-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 20px 0;
}

.ranking-panels {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 24px;
}

.ranking-panel {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 24px;
}

.ranking-panel h3 {
  font-size: 18px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.ranking-panel p {
  font-size: 14px;
  color: #6B7280;
  line-height: 1.6;
  margin-bottom: 16px;
}

.ranking-panel li {
  font-size: 14px;
  color: #4B5563;
  padding: 8px 0;
  border-bottom: 1px solid #F3F4F6;
  display: flex;
  align-items: center;
  gap: 8px;
}

.ranking-panel li:last-child {
  border-bottom: none;
}

.ranking-panel li::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #2C6E91;
  flex-shrink: 0;
}

/* 新手指南 */
.guide-entry-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 20px 0;
}

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

.guide-card {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 24px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.guide-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.06);
}

.guide-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 8px;
  background: #EAF4FA;
  font-size: 20px;
  margin-bottom: 14px;
}

.guide-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.guide-card p {
  font-size: 14px;
  color: #6B7280;
  line-height: 1.6;
}

/* 版权提示条 */
.copyright-notice {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px 0;
}

.copyright-notice p {
  background: #F3F4F6;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  padding: 14px 20px;
  font-size: 14px;
  color: #6B7280;
  text-align: center;
}

/* ============================================================
   pages · themes
   ============================================================ */
.filter-control {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.segment-control {
  display: inline-flex;
  background: #F3F4F6;
  border-radius: 6px;
  padding: 4px;
  gap: 4px;
}

.segment-btn {
  border: none;
  background: transparent;
  padding: 8px 20px;
  font-size: 14px;
  color: #6B7280;
  border-radius: 4px;
  cursor: pointer;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  transition: background 0.2s ease, color 0.2s ease;
}

.segment-btn.is-active {
  background: #FFFFFF;
  color: #2C6E91;
  font-weight: 500;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.filter-hint {
  font-size: 14px;
  color: #9CA3AF;
}

.anchor-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 24px 0 32px;
}

.anchor-nav a {
  font-size: 14px;
  color: #2C6E91;
  background: #EAF4FA;
  padding: 6px 16px;
  border-radius: 999px;
  transition: background 0.2s ease;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.anchor-nav a:hover {
  background: #d9ebf5;
}

.theme-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.theme-card {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.theme-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.06);
}

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

.theme-content {
  padding: 18px 20px 20px;
}

.theme-tag {
  display: inline-block;
  background: #EAF4FA;
  color: #2C6E91;
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
}

.theme-title {
  font-size: 19px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 6px;
}

.theme-audience {
  font-size: 14px;
  color: #6B7280;
  margin-bottom: 8px;
}

.theme-desc {
  font-size: 14px;
  color: #4B5563;
  line-height: 1.6;
  margin-bottom: 14px;
}

.theme-link {
  font-size: 14px;
  color: #2C6E91;
  font-weight: 500;
}

.theme-link:hover {
  color: #1f5573;
}

/* 相关阅读（themes） */
.related-title {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.related-desc {
  font-size: 14px;
  color: #6B7280;
  margin-bottom: 20px;
}

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

.related-link-list a {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 20px;
  font-size: 15px;
  font-weight: 500;
  color: #2C6E91;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.related-link-list a:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.06);
  color: #1f5573;
}

/* ============================================================
   pages · updates
   ============================================================ */
.filter-tags {
  margin-bottom: 32px;
}

.section-title {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.filter-desc {
  font-size: 14px;
  color: #6B7280;
  margin-bottom: 16px;
}

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

.tag-link {
  display: inline-flex;
  align-items: center;
  padding: 6px 16px;
  border-radius: 999px;
  background: #EAF4FA;
  color: #2C6E91;
  font-size: 14px;
  min-height: 44px;
  transition: background 0.2s ease;
}

.tag-link:hover {
  background: #d9ebf5;
}

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

.update-group {
  margin-bottom: 40px;
}

.group-title {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 6px;
}

.group-desc {
  font-size: 14px;
  color: #6B7280;
  margin-bottom: 16px;
}

.update-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  padding: 16px 20px;
  margin-bottom: 10px;
}

.item-tag {
  flex-shrink: 0;
  display: inline-block;
  background: #EAF4FA;
  color: #2C6E91;
  font-size: 13px;
  padding: 3px 12px;
  border-radius: 999px;
  white-space: nowrap;
}

.item-text {
  font-size: 15px;
  color: #4B5563;
  line-height: 1.6;
}

.archive-hint {
  background: #F3F4F6;
  border: 1px solid #E5E7EB;
  border-radius: 6px;
  padding: 14px 20px;
  margin-bottom: 40px;
}

.archive-hint p {
  font-size: 14px;
  color: #6B7280;
}

.archive-hint a {
  color: #2C6E91;
}

/* 相关阅读（updates） */
.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 20px;
  margin-bottom: 40px;
}

.related-card {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 20px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.related-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.06);
}

.related-card h3 {
  font-size: 16px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 6px;
}

.related-card p {
  font-size: 14px;
  color: #6B7280;
  line-height: 1.6;
}

/* ============================================================
   pages · ranking
   ============================================================ */
.ranking-rule {
  margin-bottom: 40px;
}

.ranking-rule p {
  font-size: 15px;
  color: #4B5563;
  line-height: 1.7;
  margin-bottom: 12px;
  max-width: 760px;
}

.ranking-block {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 28px;
  margin-bottom: 32px;
}

.ranking-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}

.ranking-badge {
  background: #F5A623;
  color: #FFFFFF;
  font-size: 12px;
  padding: 3px 12px;
  border-radius: 999px;
  font-weight: 500;
}

.ranking-desc {
  font-size: 14px;
  color: #6B7280;
  margin-bottom: 20px;
}

.ranking-list {
  counter-reset: ranking;
}

.ranking-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid #F3F4F6;
}

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

.ranking-num {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: #EAF4FA;
  color: #2C6E91;
  font-size: 14px;
  font-weight: 600;
}

.ranking-info {
  flex: 1;
}

.ranking-name {
  font-size: 16px;
  font-weight: 500;
  color: #1F2937;
  margin-bottom: 2px;
}

.ranking-trend {
  font-size: 14px;
  color: #6B7280;
  line-height: 1.5;
}

.ranking-links {
  margin-top: 32px;
  padding: 20px;
  background: #F3F4F6;
  border-radius: 6px;
}

.ranking-links p {
  font-size: 14px;
  color: #6B7280;
}

.ranking-links a {
  color: #2C6E91;
  margin-right: 16px;
}

/* ============================================================
   pages · guide
   ============================================================ */
.layout-shell.guide-layout {
  display: grid;
  grid-template-columns: 860px 280px;
  gap: 40px;
  align-items: start;
  margin-bottom: 40px;
}

.guide-summary {
  position: sticky;
  top: 84px;
}

.summary-inner {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 20px;
}

.summary-title {
  font-size: 16px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 14px;
}

.summary-list li {
  margin-bottom: 4px;
}

.summary-list a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  color: #4B5563;
  border-radius: 4px;
  transition: background 0.2s ease, color 0.2s ease;
}

.summary-list a:hover {
  background: #EAF4FA;
  color: #2C6E91;
}

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

.guide-section {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 28px;
  margin-bottom: 24px;
}

.guide-section h2 {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 16px;
}

.guide-section p {
  font-size: 15px;
  color: #4B5563;
  line-height: 1.7;
  margin-bottom: 12px;
}

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

.guide-section a {
  color: #2C6E91;
}

/* ============================================================
   pages · feedback
   ============================================================ */
.copyright-statement {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 28px;
  margin-bottom: 32px;
}

.copyright-statement h2 {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 16px;
}

.copyright-statement p {
  font-size: 15px;
  color: #4B5563;
  line-height: 1.7;
  margin-bottom: 12px;
}

.copyright-statement p:last-child {
  margin-bottom: 0;
}

.collection-principles {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 28px;
  margin-bottom: 32px;
}

.collection-principles h2 {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 12px;
}

.collection-principles > p {
  font-size: 15px;
  color: #4B5563;
  margin-bottom: 16px;
}

.principle-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 10px 0;
  font-size: 15px;
  color: #4B5563;
  line-height: 1.6;
}

.principle-list li::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #2C6E91;
  flex-shrink: 0;
  margin-top: 10px;
}

.feedback-faq {
  background: #FFFFFF;
  border: 1px solid #E5E7EB;
  border-radius: 8px;
  padding: 28px;
}

.feedback-faq h2 {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.feedback-faq > p {
  font-size: 15px;
  color: #6B7280;
  margin-bottom: 20px;
}

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

.faq-more {
  font-size: 14px;
  color: #6B7280;
}

.faq-more a {
  color: #2C6E91;
  margin-right: 12px;
}

/* ============================================================
   pages · 404
   ============================================================ */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  padding: 40px 20px;
}

.error-container {
  text-align: center;
  max-width: 480px;
}

.error-code {
  font-size: 72px;
  font-weight: 700;
  color: #2C6E91;
  line-height: 1.2;
  margin-bottom: 8px;
}

.error-container h1 {
  font-size: 24px;
  color: #1F2937;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: #6B7280;
  margin-bottom: 24px;
}

.error-back {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: #2C6E91;
  color: #FFFFFF;
  padding: 10px 28px;
  border-radius: 6px;
  font-size: 15px;
  min-height: 44px;
  transition: background 0.2s ease;
}

.error-back:hover {
  background: #245a78;
  color: #FFFFFF;
}

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

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

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

  .layout-shell.guide-layout {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .guide-summary {
    position: static;
    margin-bottom: 24px;
  }

  .summary-inner {
    padding: 16px 20px;
  }

  .summary-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  .summary-list li {
    margin-bottom: 0;
  }

  .summary-list a {
    padding: 6px 14px;
    background: #EAF4FA;
    border-radius: 999px;
    font-size: 13px;
  }
}

@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: #FFFFFF;
    border-bottom: 1px solid #E5E7EB;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
  }

  .site-nav .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 16px 16px;
  }

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

  .site-nav .nav-list li {
    border-bottom: 1px solid #F3F4F6;
  }

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

  .site-nav .nav-list a {
    padding: 14px 8px;
    font-size: 16px;
    border-bottom: none;
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .site-nav .nav-list a.is-current {
    color: #2C6E91;
    border-bottom: none;
  }

  .hero-section {
    flex-direction: column;
    padding: 32px 16px 36px;
    gap: 28px;
  }

  .hero-content {
    order: 1;
  }

  .hero-figure {
    order: 2;
    width: 100%;
  }

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

  .hot-tags-section,
  .recent-updates-section,
  .rankings-section,
  .guide-entry-section,
  .copyright-notice {
    padding-left: 16px;
    padding-right: 16px;
  }

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

  .ranking-panels {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .guide-cards {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .related-link-list {
    grid-template-columns: 1fr;
    gap: 16px;
  }

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

  .theme-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

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

  .filter-control {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .ranking-block {
    padding: 20px;
  }

  .guide-section {
    padding: 20px;
  }

  .copyright-statement,
  .collection-principles,
  .feedback-faq {
    padding: 20px;
  }

  .page-header {
    padding: 4px 0 16px;
  }

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

  .footer-inner {
    padding: 32px 16px 24px;
  }

  .footer-links {
    gap: 8px 16px;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    gap: 12px;
  }

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

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

  .update-card img {
    height: 180px;
  }

  .theme-media img {
    height: 200px;
  }

  .ranking-head {
    flex-wrap: wrap;
  }

  .update-item {
    flex-direction: column;
    gap: 8px;
  }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .section-more {
    align-self: flex-start;
  }

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

  .anchor-nav a {
    padding: 4px 14px;
    font-size: 13px;
  }

  .tag-link {
    padding: 4px 14px;
    font-size: 13px;
  }

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