:root {
  --color-bg: #F7F5F0;
  --color-surface: #FFFFFF;
  --color-text: #2C2C2C;
  --color-muted: #6B6B6B;
  --color-accent: #3A5A40;
  --color-accent-soft: #E4EAE2;
  --color-line: #D9D5CC;
  --color-line-strong: #BFB9AB;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --radius-sm: 4px;
  --radius-md: 8px;
  --shadow-card: 0 1px 2px rgba(44, 44, 44, 0.06);
  --shadow-lift: 0 6px 18px rgba(44, 44, 44, 0.10);
  --container: 1080px;
  --gap-lg: 40px;
  --gap-md: 24px;
  --gap-sm: 12px;
}

/* ==========================================================================
   base
   ========================================================================== */

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

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

body {
  margin: 0;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.7;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 600;
  line-height: 1.35;
  color: var(--color-text);
}

p {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

dl,
dd,
dt {
  margin: 0;
}

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

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

a:hover,
a:focus-visible {
  color: #2A4430;
  text-decoration: underline;
  text-underline-offset: 3px;
}

button {
  font: inherit;
  color: inherit;
}

table {
  border-collapse: collapse;
  width: 100%;
}

caption {
  text-align: left;
}

figure {
  margin: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ==========================================================================
   layout · 全站骨架
   ========================================================================== */

.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background-color: rgba(247, 245, 240, 0.96);
  border-bottom: 1px solid var(--color-line);
}

.header-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--gap-md);
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px 24px;
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 2px;
  color: var(--color-text);
  text-decoration: none;
}

.brand:hover,
.brand:focus-visible {
  color: var(--color-text);
  text-decoration: none;
}

.brand-name {
  font-size: 19px;
  font-weight: 600;
  line-height: 1.3;
}

.brand-tag {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.4;
}

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

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

.nav-link {
  display: block;
  padding: 8px 12px;
  font-size: 15px;
  color: var(--color-text);
  border-bottom: 2px solid transparent;
  white-space: nowrap;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom-color: var(--color-line-strong);
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0 10px;
  background-color: transparent;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  height: 2px;
  width: 100%;
  background-color: var(--color-text);
}

.site-main {
  flex: 1 0 auto;
  width: 100%;
}

.home-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px 24px 64px;
}

.inner-main {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 28px 24px 64px;
}

.page-layout {
  display: grid;
  gap: var(--gap-lg);
}

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

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

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

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

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

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

.page-header {
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--color-line);
}

.page-title {
  font-size: 32px;
  font-weight: 600;
  line-height: 1.3;
}

.page-description {
  margin-top: 12px;
  max-width: 760px;
  font-size: 16px;
  color: var(--color-muted);
}

.site-footer {
  flex-shrink: 0;
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-line);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(220px, 1.4fr) minmax(160px, 1fr) minmax(200px, 1.2fr);
  gap: var(--gap-lg);
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px 24px 24px;
}

.footer-brand-name {
  font-size: 17px;
  font-weight: 600;
}

.footer-brand-desc {
  margin-top: 8px;
  font-size: 14px;
  color: var(--color-muted);
}

.footer-nav-title,
.footer-note-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
}

.footer-nav-list {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-nav-list a {
  font-size: 14px;
  color: var(--color-muted);
}

.footer-nav-list a:hover,
.footer-nav-list a:focus-visible {
  color: var(--color-accent);
}

.footer-note-text {
  margin-top: 10px;
  font-size: 14px;
  color: var(--color-muted);
}

.footer-bottom {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px 24px 28px;
  border-top: 1px solid var(--color-line);
}

.footer-copy {
  font-size: 13px;
  color: var(--color-muted);
}

/* ==========================================================================
   components · 通用元素
   ========================================================================== */

.section-title {
  font-size: 24px;
  font-weight: 600;
}

.section-desc,
.section-intro {
  margin-top: 10px;
  max-width: 780px;
  font-size: 15px;
  color: var(--color-muted);
}

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

.section-foot {
  margin-top: 20px;
  font-size: 15px;
}

.text-link {
  display: inline-block;
  font-size: 15px;
  color: var(--color-accent);
  border-bottom: 1px solid var(--color-accent-soft);
  padding-bottom: 2px;
}

.text-link:hover,
.text-link:focus-visible {
  border-bottom-color: var(--color-accent);
  text-decoration: none;
}

.section-note {
  margin-top: 16px;
  font-size: 14px;
  color: var(--color-muted);
}

.figure,
.figure-block,
.figure-timeline,
.channel-figure,
.lead-figure,
.lead-item-figure,
.topic-media,
.channel-media {
  overflow: hidden;
  border-radius: var(--radius-md);
  background-color: var(--color-accent-soft);
}

.figure img,
.figure-block img,
.figure-timeline img,
.channel-figure img,
.lead-figure img,
.lead-item-figure img,
.topic-media img,
.channel-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.figure-caption,
.lead-caption,
.channel-figure figcaption,
.topic-caption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--color-muted);
}

/* 数据表 */

.data-table,
.channel-table,
.scope-table {
  width: 100%;
  font-size: 15px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.data-table th,
.data-table td,
.channel-table th,
.channel-table td,
.scope-table th,
.scope-table td {
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--color-line);
}

.data-table thead th,
.channel-table thead th,
.scope-table thead th {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  background-color: #F1EEE7;
  white-space: nowrap;
}

.data-table tbody th,
.channel-table tbody th,
.scope-table tbody th {
  font-weight: 600;
  color: var(--color-text);
}

.data-table tbody tr:last-child th,
.data-table tbody tr:last-child td,
.channel-table tbody tr:last-child th,
.channel-table tbody tr:last-child td,
.scope-table tbody tr:last-child th,
.scope-table tbody tr:last-child td {
  border-bottom: none;
}

.table-scroll,
.table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.table-caption,
.scope-table-caption {
  margin-bottom: 10px;
  font-size: 13px;
  color: var(--color-muted);
}

.table-link {
  color: var(--color-accent);
}

/* 侧栏 / 目录 */

.page-aside,
.sidebar {
  min-width: 0;
  font-size: 14px;
}

.toc-title,
.sidebar-links-title,
.aside-title,
.related-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text);
}

.toc-list {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.toc-list a,
.toc-link {
  display: block;
  padding: 5px 0 5px 10px;
  color: var(--color-muted);
  border-left: 2px solid var(--color-line);
}

.toc-list a:hover,
.toc-list a:focus-visible,
.toc-list a.is-active,
.toc-link:hover,
.toc-link:focus-visible,
.toc-link.is-active {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  text-decoration: none;
}

.aside-note,
.sidebar-links,
.progress-note,
.aside-block {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--color-line);
}

.aside-note-text,
.sidebar-link-list,
.progress-note-label,
.progress-text {
  margin-top: 10px;
  font-size: 14px;
  color: var(--color-muted);
}

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

.sidebar-link-list a,
.aside-link-list a {
  color: var(--color-accent);
}

.aside-link-list {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.progress-note-bar {
  display: block;
  width: 100%;
  height: 3px;
  margin-top: 10px;
  background-color: var(--color-line);
  border-radius: 2px;
}

.progress-note-bar::after {
  content: "";
  display: block;
  width: 40%;
  height: 100%;
  background-color: var(--color-accent);
  border-radius: 2px;
}

.progress-track {
  margin-top: 10px;
  height: 4px;
  background-color: var(--color-line);
  border-radius: 2px;
  overflow: hidden;
}

.progress-bar {
  display: block;
  width: 35%;
  height: 100%;
  background-color: var(--color-accent);
}

.related-links {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--color-line);
}

.related-list {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.related-list a {
  color: var(--color-accent);
}

/* ==========================================================================
   pages · 首页
   ========================================================================== */

.home-lead {
  padding-bottom: 48px;
  border-bottom: 1px solid var(--color-line);
}

.lead-head {
  max-width: 760px;
  margin-bottom: 32px;
}

.lead-kicker {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
}

.lead-title {
  margin-top: 10px;
  font-size: 34px;
  font-weight: 600;
  line-height: 1.3;
}

.lead-intro {
  margin-top: 14px;
  font-size: 16px;
  color: var(--color-muted);
}

.lead-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(260px, 1fr);
  gap: var(--gap-lg);
  align-items: start;
}

.lead-feature {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.lead-figure {
  border-radius: 0;
  aspect-ratio: 16 / 9;
}

.lead-feature-body {
  padding: 22px 24px 26px;
}

.lead-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
}

.lead-feature-title {
  margin-top: 8px;
  font-size: 22px;
}

.lead-feature-text {
  margin-top: 12px;
  font-size: 15px;
  color: var(--color-muted);
}

.lead-feature-body .text-link {
  margin-top: 16px;
}

.lead-side {
  display: flex;
  flex-direction: column;
  gap: var(--gap-md);
}

.lead-item {
  display: flex;
  flex-direction: column;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  padding: 16px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.lead-item:hover,
.lead-item:focus-within {
  transform: translateY(-2px);
  border-color: var(--color-line-strong);
  box-shadow: var(--shadow-lift);
}

.lead-item-figure {
  aspect-ratio: 16 / 10;
}

.lead-item-title {
  margin-top: 12px;
  font-size: 17px;
}

.lead-item-text {
  margin-top: 8px;
  font-size: 14px;
  color: var(--color-muted);
}

.lead-item .text-link {
  margin-top: 12px;
}

.home-channels,
.home-topics,
.home-changes,
.home-boundary {
  padding: 48px 0;
  border-bottom: 1px solid var(--color-line);
}

.home-boundary {
  border-bottom: none;
}

.channel-table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.channel-figure {
  margin-top: 24px;
  aspect-ratio: 21 / 9;
}

.topic-card-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--gap-md);
}

.home-topics .topic-card {
  display: flex;
  flex-direction: column;
  padding: 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.home-topics .topic-card:hover,
.home-topics .topic-card:focus-within {
  transform: translateY(-2px);
  border-color: var(--color-line-strong);
  box-shadow: var(--shadow-lift);
}

.topic-card-title {
  font-size: 18px;
}

.topic-card-scope,
.topic-card-dir {
  margin-top: 10px;
  font-size: 14px;
  color: var(--color-muted);
}

.field-name {
  display: block;
  margin-bottom: 2px;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-accent);
}

.change-month-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--gap-md);
}

.change-month {
  padding: 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.change-month-title {
  font-size: 17px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-line);
}

.change-entry-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.change-entry {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.change-type {
  align-self: flex-start;
  padding: 1px 8px;
  font-size: 12px;
  color: var(--color-accent);
  background-color: var(--color-accent-soft);
  border-radius: var(--radius-sm);
}

.change-text {
  font-size: 14px;
  color: var(--color-muted);
}

.boundary-body {
  margin-top: 18px;
  max-width: 800px;
}

.boundary-text {
  font-size: 15px;
  color: var(--color-muted);
}

.home-boundary .boundary-text + .boundary-text {
  margin-top: 12px;
}

.boundary-links {
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

/* ==========================================================================
   pages · 频道分类
   ========================================================================== */

.page-channels .page-layout,
.page-guide .page-layout,
.page-changes .page-layout {
  grid-template-columns: minmax(200px, 240px) minmax(0, 1fr);
}

.section {
  margin-top: 40px;
}

.section:first-of-type {
  margin-top: 0;
}

.section-channel-table .table-scroll {
  margin-top: 20px;
}

.section-channel-detail .channel-block {
  display: grid;
  grid-template-columns: minmax(200px, 300px) minmax(0, 1fr);
  gap: var(--gap-md);
  align-items: start;
  padding: 24px 0;
  border-top: 1px solid var(--color-line);
}

.section-channel-detail .channel-block:first-of-type {
  border-top: none;
  padding-top: 8px;
}

.channel-media .figure {
  aspect-ratio: 4 / 3;
}

.channel-title {
  font-size: 18px;
}

.channel-text {
  margin-top: 10px;
  font-size: 15px;
  color: var(--color-muted);
}

.channel-label {
  margin-top: 14px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
}

.topic-list {
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.topic-list li {
  font-size: 14px;
  color: var(--color-text);
  padding-left: 14px;
  position: relative;
}

.topic-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 5px;
  height: 5px;
  background-color: var(--color-line-strong);
  border-radius: 50%;
}

.section-related .related-list {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--gap-md);
}

.related-item {
  padding: 18px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.related-link {
  display: block;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-accent);
}

.related-text {
  margin-top: 8px;
  font-size: 14px;
  color: var(--color-muted);
}

/* ==========================================================================
   pages · 专题片单
   ========================================================================== */

.page-topics .page-layout {
  grid-template-columns: minmax(0, 1fr) minmax(200px, 240px);
}

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

.page-topics .page-header {
  padding-bottom: 20px;
}

.content-section {
  margin-top: 40px;
}

.content-section:first-of-type {
  margin-top: 0;
}

.page-topics .topic-card {
  display: grid;
  grid-template-columns: minmax(180px, 260px) minmax(0, 1fr);
  gap: var(--gap-md);
  align-items: start;
  padding: 24px 0;
  border-top: 1px solid var(--color-line);
}

.page-topics .topic-card:first-of-type {
  border-top: none;
  padding-top: 8px;
}

.topic-media {
  aspect-ratio: 4 / 3;
}

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

.topic-summary {
  margin-top: 10px;
  font-size: 15px;
  color: var(--color-muted);
}

.topic-meta {
  margin-top: 14px;
  display: grid;
  grid-template-columns: minmax(80px, auto) minmax(0, 1fr);
  gap: 6px 14px;
  font-size: 14px;
}

.topic-meta dt {
  font-weight: 600;
  color: var(--color-text);
}

.topic-meta dd {
  color: var(--color-muted);
}

.topic-link {
  margin-top: 14px;
  font-size: 15px;
}

.scope-table {
  margin-top: 20px;
}

.scope-note,
.criteria-note {
  margin-top: 16px;
  font-size: 14px;
  color: var(--color-muted);
}

.criteria-grid {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--gap-md);
}

.criteria-item {
  padding: 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.criteria-title {
  font-size: 17px;
}

.criteria-text {
  margin-top: 10px;
  font-size: 14px;
  color: var(--color-muted);
}

/* ==========================================================================
   pages · 观看指引
   ========================================================================== */

.page-guide .page-aside .aside-block:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

.figure-block {
  margin-top: 20px;
  aspect-ratio: 21 / 9;
}

.step-list {
  margin-top: 24px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--gap-md);
  counter-reset: step;
}

.step-item {
  position: relative;
  padding: 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.step-item::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  display: block;
  margin-bottom: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
}

.step-title {
  font-size: 17px;
}

.step-text {
  margin-top: 8px;
  font-size: 14px;
  color: var(--color-muted);
}

.step-link {
  margin-top: 10px;
  font-size: 14px;
}

.faq-list {
  margin-top: 20px;
  border-top: 1px solid var(--color-line);
}

.faq-item {
  border-bottom: 1px solid var(--color-line);
}

.faq-question {
  position: relative;
  padding: 16px 36px 16px 0;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: 16px;
  font-size: 18px;
  font-weight: 400;
  color: var(--color-accent);
}

.faq-item[open] .faq-question::after {
  content: "–";
}

.faq-question:hover,
.faq-question:focus-visible {
  color: var(--color-accent);
}

.faq-answer {
  padding: 0 36px 18px 0;
  font-size: 15px;
  color: var(--color-muted);
}

.boundary-grid {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--gap-md);
}

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

.boundary-title {
  font-size: 17px;
}

.boundary-card .boundary-text {
  margin-top: 10px;
  font-size: 14px;
  color: var(--color-muted);
}

.subsection-title {
  margin-top: 32px;
  font-size: 18px;
}

.page-guide .related-list {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--gap-sm);
}

/* ==========================================================================
   pages · 内容变动记录
   ========================================================================== */

.figure-timeline {
  margin-top: 20px;
  aspect-ratio: 21 / 9;
}

.archive-group {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--color-line);
}

.archive-group:first-of-type {
  margin-top: 24px;
}

.archive-month {
  font-size: 18px;
}

.archive-list {
  margin-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.archive-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 14px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.archive-type {
  flex-shrink: 0;
  padding: 1px 8px;
  font-size: 12px;
  color: var(--color-accent);
  background-color: var(--color-accent-soft);
  border-radius: var(--radius-sm);
}

.archive-text {
  flex: 1 1 260px;
  min-width: 0;
  font-size: 15px;
}

.archive-scope {
  flex: 1 1 100%;
  font-size: 13px;
  color: var(--color-muted);
}

.type-list {
  margin-top: 20px;
  display: grid;
  gap: var(--gap-md);
}

.type-item {
  display: grid;
  grid-template-columns: minmax(120px, 180px) minmax(0, 1fr);
  gap: var(--gap-md);
  padding: 16px 0;
  border-top: 1px solid var(--color-line);
}

.type-item:first-child {
  border-top: none;
  padding-top: 0;
}

.type-name {
  font-size: 16px;
  font-weight: 600;
}

.type-desc {
  font-size: 15px;
  color: var(--color-muted);
}

.progress-hint {
  margin-top: 40px;
  padding: 18px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-left: 3px solid var(--color-accent);
  border-radius: var(--radius-md);
}

.progress-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 15px;
}

/* ==========================================================================
   pages · 404
   ========================================================================== */

.error-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 64px 24px 80px;
}

.error-hero {
  max-width: 640px;
}

.error-code {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
}

.error-hero h1 {
  margin-top: 12px;
  font-size: 32px;
}

.error-text {
  margin-top: 14px;
  font-size: 16px;
  color: var(--color-muted);
}

.error-home-link {
  display: inline-block;
  margin-top: 22px;
  padding: 11px 22px;
  min-height: 44px;
  font-size: 15px;
  color: var(--color-surface);
  background-color: var(--color-accent);
  border-radius: var(--radius-md);
}

.error-home-link:hover,
.error-home-link:focus-visible {
  color: var(--color-surface);
  background-color: #2A4430;
  text-decoration: none;
}

.error-paths {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--color-line);
}

.error-paths h2 {
  font-size: 24px;
}

.error-path-list {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--gap-md);
}

.error-path-item {
  padding: 18px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.error-path-item a {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-accent);
}

.error-path-item p {
  margin-top: 8px;
  font-size: 14px;
  color: var(--color-muted);
}

/* ==========================================================================
   responsive
   ========================================================================== */

@media (max-width: 960px) {

  .lead-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }

  .footer-note {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {

  .header-inner {
    flex-wrap: wrap;
    gap: 12px;
    padding: 14px 20px;
  }

  .nav-toggle {
    display: flex;
    order: 3;
  }

  .site-nav {
    order: 4;
    width: 100%;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
    padding: 8px 0 4px;
    border-top: 1px solid var(--color-line);
  }

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

  .nav-link {
    padding: 12px 4px;
    border-bottom: 1px solid var(--color-line);
    border-left: none;
  }

  .nav-link.is-current {
    border-bottom-color: var(--color-line);
    border-left: 3px solid var(--color-accent);
    padding-left: 12px;
  }

  .home-main,
  .inner-main {
    padding: 28px 20px 56px;
  }

  .page-title,
  .lead-title,
  .error-hero h1 {
    font-size: 26px;
  }

  .section-title,
  .error-paths h2 {
    font-size: 21px;
  }

  .page-layout,
  .page-channels .page-layout,
  .page-guide .page-layout,
  .page-changes .page-layout,
  .page-topics .page-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 32px;
  }

  .page-channels .page-aside,
  .page-guide .page-aside,
  .page-changes .page-aside,
  .page-topics .sidebar {
    order: 2;
  }

  .page-channels .page-content,
  .page-guide .page-content,
  .page-changes .page-content,
  .page-topics .page-layout > .content-section {
    order: 1;
  }

  .page-topics .page-layout {
    display: flex;
    flex-direction: column;
  }

  .page-topics .sidebar {
    order: 3;
  }

  .section-channel-detail .channel-block,
  .page-topics .topic-card,
  .type-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .topic-meta {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  .topic-meta dt {
    margin-top: 8px;
  }

  .channel-figure,
  .figure-block,
  .figure-timeline {
    aspect-ratio: 16 / 9;
  }

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
    padding: 32px 20px 20px;
  }

  .footer-bottom {
    padding: 14px 20px 24px;
  }

  .error-main {
    padding: 40px 20px 64px;
  }
}

@media (max-width: 420px) {

  .header-inner {
    padding: 12px 16px;
  }

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

  .footer-inner,
  .footer-bottom {
    padding-left: 16px;
    padding-right: 16px;
  }

  .brand-name {
    font-size: 17px;
  }

  .lead-feature-body,
  .home-topics .topic-card,
  .change-month,
  .criteria-item,
  .boundary-card,
  .step-item,
  .related-item {
    padding: 16px;
  }

  .data-table th,
  .data-table td,
  .channel-table th,
  .channel-table td,
  .scope-table th,
  .scope-table td {
    padding: 10px;
    font-size: 14px;
  }

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