:root {
  --ink: #1f2329;
  --ink-soft: #5a6472;
  --ink-faint: #7d8794;
  --bg: #f7f8fa;
  --card: #ffffff;
  --line: #e3e6ea;
  --line-strong: #cfd5dc;
  --brand: #2f6f8f;
  --brand-deep: #245a75;
  --brand-wash: #eef4f7;
  --warn: #b45309;
  --warn-wash: #fdf6ec;
  --ok: #2f7d5c;
  --ok-wash: #edf6f1;
  --radius: 6px;
  --radius-sm: 4px;
  --wrap: 1120px;
  --wrap-narrow: 860px;
  --gap: 24px;
  --header-h: 64px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

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

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.4;
}

p {
  margin: 0;
}

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

dl,
dd,
dt {
  margin: 0;
}

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

a:hover {
  color: var(--brand-deep);
  text-decoration: underline;
}

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

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
}

/* ============ layout ============ */

.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
}

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

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

.home-main {
  width: 100%;
}

.section {
  margin-top: 48px;
}

.section:first-child {
  margin-top: 0;
}

.content-section {
  margin-top: 48px;
}

.section-head {
  margin-bottom: 20px;
}

.section-title {
  font-size: 22px;
  line-height: 1.4;
  color: var(--ink);
}

.section-desc,
.section-intro {
  margin-top: 8px;
  max-width: 780px;
  font-size: 15px;
  color: var(--ink-soft);
}

.section-more {
  margin-top: 16px;
  font-size: 15px;
}

.section-footnote {
  margin-top: 18px;
  font-size: 15px;
  color: var(--ink-soft);
}

.section-footnote a {
  margin-right: 16px;
}

.section-media {
  margin: 20px 0 24px;
}

.section-media img {
  width: 100%;
  max-height: 320px;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
}

.section-media figcaption {
  margin-top: 8px;
  font-size: 14px;
  color: var(--ink-faint);
}

.link-inline {
  font-size: 15px;
  font-weight: 600;
}

/* ============ header & nav ============ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--card);
  border-bottom: 1px solid var(--line);
}

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

.brand-logo {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  white-space: nowrap;
}

.brand-logo:hover {
  color: var(--brand-deep);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  padding: 0 12px;
  background: var(--card);
  color: var(--ink);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  font-size: 15px;
}

.site-nav {
  display: block;
}

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

.nav-list li {
  display: block;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  font-size: 15px;
  color: var(--ink-soft);
  border-radius: var(--radius-sm);
}

.nav-link:hover {
  color: var(--brand-deep);
  background: var(--brand-wash);
  text-decoration: none;
}

.nav-link.is-current {
  color: var(--brand-deep);
  font-weight: 700;
  background: var(--brand-wash);
}

/* ============ breadcrumb & page header ============ */

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: 20px 0 0;
  font-size: 14px;
  color: var(--ink-faint);
}

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

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

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

.page-header {
  padding: 16px 0 24px;
  border-bottom: 1px solid var(--line);
}

.page-title {
  font-size: 32px;
  line-height: 1.3;
  font-weight: 700;
  color: var(--ink);
}

.page-description {
  margin-top: 12px;
  max-width: 780px;
  font-size: 16px;
  color: var(--ink-soft);
}

.page-description a {
  margin-right: 12px;
  font-weight: 600;
}

/* ============ clue bar ============ */

.clue-bar {
  background: var(--brand-wash);
  border-bottom: 1px solid var(--line);
}

.clue-text {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 10px 24px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-soft);
}

/* ============ hero (home) ============ */

.hero-status {
  padding: 40px 0 8px;
}

.hero-status-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 440px);
  gap: 40px;
  align-items: start;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
}

.hero-copy {
  min-width: 0;
}

.hero-eyebrow {
  display: inline-block;
  padding: 4px 10px;
  background: var(--ok-wash);
  color: var(--ok);
  border: 1px solid #cfe6da;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.6;
}

.hero-title {
  margin-top: 16px;
  font-size: 32px;
  line-height: 1.3;
  font-weight: 700;
}

.hero-lead {
  margin-top: 14px;
  max-width: 620px;
  font-size: 16px;
  color: var(--ink-soft);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: var(--brand);
  color: #ffffff;
  border-color: var(--brand);
}

.btn-primary:hover {
  background: var(--brand-deep);
  border-color: var(--brand-deep);
  color: #ffffff;
}

.btn-ghost {
  background: var(--card);
  color: var(--brand-deep);
  border-color: var(--line-strong);
}

.btn-ghost:hover {
  background: var(--brand-wash);
  border-color: var(--brand);
  color: var(--brand-deep);
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.metric-item {
  min-width: 0;
  padding: 12px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.metric-term {
  font-size: 13px;
  color: var(--ink-faint);
}

.metric-value {
  margin-top: 4px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.hero-figure {
  margin: 0;
  min-width: 0;
}

.hero-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
}

.hero-caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-faint);
}

/* ============ channel overview (home) ============ */

.channel-overview,
.collection-timeline,
.browse-steps,
.field-summary,
.site-index {
  max-width: var(--wrap);
  margin: 48px auto 0;
  padding: 0 24px;
}

.channel-list {
  border-top: 1px solid var(--line);
}

.channel-overview .channel-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) minmax(0, 240px);
  gap: 20px;
  align-items: start;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.channel-index {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.channel-body {
  min-width: 0;
}

.channel-name {
  font-size: 17px;
  line-height: 1.5;
}

.channel-desc {
  margin-top: 6px;
  font-size: 15px;
  color: var(--ink-soft);
}

.channel-audience {
  min-width: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-faint);
}

/* ============ collection timeline (home) ============ */

.timeline-group {
  margin-top: 28px;
}

.timeline-group:first-child {
  margin-top: 0;
}

.timeline-stage {
  display: inline-block;
  padding: 4px 12px;
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.timeline-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin-top: 16px;
}

.timeline-item {
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.timeline-item:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.timeline-figure {
  margin: 0;
}

.timeline-figure img {
  width: 100%;
  height: 170px;
  object-fit: cover;
  background: var(--bg);
}

.timeline-body {
  min-width: 0;
  padding: 16px;
}

.timeline-name {
  font-size: 17px;
  line-height: 1.5;
}

.timeline-desc {
  margin-top: 8px;
  font-size: 15px;
  color: var(--ink-soft);
}

.timeline-tags {
  margin-top: 12px;
  font-size: 13px;
  color: var(--ink-faint);
}

/* ============ browse steps (home) ============ */

.browse-steps .step-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
}

.browse-steps .step-item {
  position: relative;
  min-width: 0;
  padding: 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-top: 3px solid var(--brand);
  border-radius: var(--radius);
}

.browse-steps .step-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--brand);
}

.browse-steps .step-name {
  margin-top: 6px;
  font-size: 17px;
  line-height: 1.5;
}

.browse-steps .step-action {
  margin-top: 8px;
  font-size: 15px;
  color: var(--ink-soft);
}

.browse-steps .step-check {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 14px;
  color: var(--ink-soft);
}

.browse-steps .step-warn {
  margin-top: 8px;
  padding: 8px 10px;
  background: var(--warn-wash);
  border-left: 3px solid var(--warn);
  border-radius: var(--radius-sm);
  font-size: 13px;
  line-height: 1.65;
  color: var(--warn);
}

/* ============ field summary (home) ============ */

.field-summary-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 24px;
}

.field-column,
.boundary-column {
  min-width: 0;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.column-title {
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  font-size: 17px;
  line-height: 1.5;
}

.field-list {
  margin-top: 12px;
}

.field-row {
  display: grid;
  grid-template-columns: minmax(0, 130px) minmax(0, 1fr);
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px dashed var(--line);
}

.field-row:last-child {
  border-bottom: 0;
}

.field-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
}

.field-value {
  min-width: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.boundary-list {
  margin-top: 12px;
}

.boundary-item {
  position: relative;
  padding: 8px 0 8px 18px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
  border-bottom: 1px dashed var(--line);
}

.boundary-item:last-child {
  border-bottom: 0;
}

.boundary-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  width: 6px;
  height: 6px;
  background: var(--warn);
  border-radius: 50%;
}

.boundary-more {
  margin-top: 12px;
  font-size: 14px;
}

/* ============ site index (home) ============ */

.index-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}

.index-card {
  min-width: 0;
  padding: 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.index-card:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.index-name {
  font-size: 16px;
  line-height: 1.5;
}

.index-desc {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ============ channel tree (channels) ============ */

.tree-wrap {
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.tree-root {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px 28px;
}

.tree-branch {
  min-width: 0;
}

.tree-node {
  display: block;
  padding: 6px 10px;
  background: var(--brand-wash);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 700;
  color: var(--brand-deep);
}

.tree-children {
  margin-top: 8px;
  padding-left: 14px;
  border-left: 1px dashed var(--line-strong);
}

.tree-leaf {
  padding: 5px 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ============ channel rows (channels) ============ */

.channel-rows {
  border-top: 1px solid var(--line);
}

.section-channel-list .channel-row {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.channel-thumb {
  margin: 0;
  min-width: 0;
}

.channel-thumb img {
  width: 100%;
  height: 130px;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
}

.section-channel-list .channel-body {
  min-width: 0;
}

.section-channel-list .channel-index {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--brand);
}

.section-channel-list .channel-name {
  margin-top: 4px;
  font-size: 18px;
  line-height: 1.5;
}

.channel-meta {
  display: grid;
  grid-template-columns: minmax(0, 110px) minmax(0, 1fr);
  gap: 6px 14px;
  margin-top: 12px;
}

.channel-meta dt {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
}

.channel-meta dd {
  min-width: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.channel-note {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-faint);
}

/* ============ notes columns (channels) ============ */

.notes-columns {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 24px;
}

.notes-col {
  min-width: 0;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.notes-col-title {
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  font-size: 17px;
  line-height: 1.5;
}

/* ============ tables ============ */

.field-table,
.map-table,
.info-table {
  width: 100%;
  margin-top: 14px;
  border-collapse: collapse;
  background: var(--card);
  font-size: 14px;
}

.field-table-caption,
.table-caption,
.map-caption {
  caption-side: top;
  padding: 0 0 10px;
  text-align: left;
  font-size: 14px;
  color: var(--ink-faint);
}

.field-table th,
.field-table td,
.map-table th,
.map-table td,
.info-table th,
.info-table td {
  padding: 10px 12px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
  line-height: 1.7;
}

.field-table thead th,
.map-table thead th,
.info-table thead th {
  background: var(--brand-wash);
  color: var(--brand-deep);
  font-weight: 700;
}

.field-table tbody th,
.map-table tbody th,
.info-table tbody th {
  width: 200px;
  color: var(--ink);
  font-weight: 700;
  background: #fbfcfd;
}

.field-table td,
.map-table td,
.info-table td {
  min-width: 0;
  color: var(--ink-soft);
}

/* ============ collections ============ */

.collection-row {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.collection-row:first-of-type {
  border-top: 1px solid var(--line);
}

.collection-figure {
  margin: 0;
  min-width: 0;
}

.collection-figure img {
  width: 100%;
  height: 160px;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
}

.collection-body {
  min-width: 0;
}

.collection-name {
  font-size: 18px;
  line-height: 1.5;
}

.collection-theme {
  margin-top: 8px;
  font-size: 15px;
  color: var(--ink-soft);
}

.collection-scope {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 14px;
  color: var(--ink-faint);
}

.order-row {
  display: grid;
  grid-template-columns: minmax(0, 240px) minmax(0, 1fr);
  gap: 20px;
  align-items: start;
  padding: 16px 0;
  border-bottom: 1px dashed var(--line);
}

.order-row:last-child {
  border-bottom: 0;
}

.order-name {
  font-size: 16px;
  line-height: 1.5;
}

.order-reason {
  min-width: 0;
  font-size: 15px;
  color: var(--ink-soft);
}

.note-list {
  margin-top: 16px;
  padding: 18px 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius);
}

.note-item {
  padding: 8px 0 8px 18px;
  position: relative;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
  border-bottom: 1px dashed var(--line);
}

.note-item:last-child {
  border-bottom: 0;
}

.note-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 6px;
  height: 6px;
  background: var(--brand);
  border-radius: 50%;
}

/* ============ guide steps (browse-guide) ============ */

.guide-steps .step-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.guide-steps .step-item {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 16px;
  min-width: 0;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.guide-steps .step-item:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.guide-steps .step-index {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: var(--brand-wash);
  border: 1px solid #d5e4ec;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 700;
  color: var(--brand-deep);
}

.guide-steps .step-body {
  min-width: 0;
}

.guide-steps .step-name {
  font-size: 17px;
  line-height: 1.5;
}

.guide-steps .step-action {
  margin-top: 8px;
  font-size: 15px;
  color: var(--ink-soft);
}

.step-figure {
  margin: 14px 0 0;
}

.step-figure img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--bg);
}

.step-figure figcaption {
  margin-top: 6px;
  font-size: 13px;
  color: var(--ink-faint);
}

/* ============ FAQ ============ */

.faq-item {
  margin-top: 12px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

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

.faq-question {
  position: relative;
  padding: 14px 44px 14px 18px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--brand);
}

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

.faq-question:hover {
  background: var(--brand-wash);
}

.faq-answer {
  padding: 0 18px 16px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

/* ============ related links ============ */

.related-list,
.related-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.related-item {
  min-width: 0;
  padding: 14px 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.related-item:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.related-item a {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--brand-deep);
}

.related-item a:hover {
  text-decoration: none;
}

/* ============ notice block ============ */

.notice-block {
  margin: 18px 0 20px;
  padding: 16px 18px;
  background: var(--warn-wash);
  border: 1px solid #f0dcc0;
  border-left: 3px solid var(--warn);
  border-radius: var(--radius);
}

.notice-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--warn);
}

.notice-text {
  margin-top: 6px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ============ field notes boundary items ============ */

.section-boundary .boundary-item {
  padding: 14px 0 14px 18px;
}

.section-boundary .boundary-item::before {
  top: 22px;
}

.boundary-item-title {
  font-size: 16px;
  line-height: 1.5;
  color: var(--ink);
}

.boundary-item-text {
  margin-top: 6px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

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

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 64px 24px;
}

.error-inner {
  width: 100%;
  max-width: 640px;
  padding: 32px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-align: center;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  color: var(--brand);
  line-height: 1.2;
}

.error-title {
  margin-top: 8px;
  font-size: 26px;
  line-height: 1.4;
}

.error-desc {
  margin-top: 12px;
  font-size: 15px;
  color: var(--ink-soft);
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 22px;
}

.error-hints {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  text-align: left;
}

.error-hints-title {
  font-size: 16px;
  line-height: 1.5;
}

.error-hint-list {
  margin-top: 10px;
}

.error-hint-list li {
  padding: 8px 0 8px 18px;
  position: relative;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
  border-bottom: 1px dashed var(--line);
}

.error-hint-list li:last-child {
  border-bottom: 0;
}

.error-hint-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  width: 6px;
  height: 6px;
  background: var(--brand);
  border-radius: 50%;
}

/* ============ footer ============ */

.site-footer {
  margin-top: 64px;
  background: var(--card);
  border-top: 1px solid var(--line);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) repeat(4, minmax(0, 1fr));
  gap: 28px;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 40px 24px 28px;
}

.footer-brand {
  min-width: 0;
}

.footer-brand-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.footer-brand-desc {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.footer-group {
  min-width: 0;
}

.footer-group-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.footer-links {
  margin-top: 10px;
}

.footer-links li {
  padding: 5px 0;
}

.footer-links a {
  display: inline-block;
  min-height: 28px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.footer-links a:hover {
  color: var(--brand-deep);
}

.footer-copyright {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 16px 24px 28px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--ink-faint);
}

/* ============ reveal enhancement ============ */

.reveal-ready .reveal {
  animation: reveal-fade 0.5s ease both;
}

@keyframes reveal-fade {
  from {
    opacity: 0.35;
  }

  to {
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal-ready .reveal {
    animation: none;
  }

  .timeline-item:hover,
  .index-card:hover,
  .guide-steps .step-item:hover,
  .related-item:hover {
    transform: none;
  }
}

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

@media (max-width: 1024px) {
  .hero-status-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
  }

  .hero-figure img {
    height: 260px;
  }

  .browse-steps .step-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .index-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .footer-inner {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }
}

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

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    flex-basis: 100%;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 8px 0 12px;
    border-top: 1px solid var(--line);
  }

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

  .nav-link {
    justify-content: flex-start;
    padding: 0 12px;
  }

  .clue-text {
    padding: 10px 16px;
  }

  .inner-main {
    padding: 0 16px 48px;
  }

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

  .hero-status {
    padding-top: 28px;
  }

  .hero-status-inner {
    padding: 0 16px;
  }

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

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

  .channel-overview,
  .collection-timeline,
  .browse-steps,
  .field-summary,
  .site-index {
    margin-top: 40px;
    padding: 0 16px;
  }

  .channel-overview .channel-row {
    grid-template-columns: 40px minmax(0, 1fr);
    gap: 12px;
  }

  .channel-overview .channel-audience {
    grid-column: 2;
  }

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

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

  .index-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .section-channel-list .channel-row,
  .collection-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 14px;
  }

  .channel-thumb img,
  .collection-figure img {
    height: 180px;
  }

  .order-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

  .guide-steps .step-list {
    grid-template-columns: minmax(0, 1fr);
  }

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

  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    padding: 32px 16px 24px;
  }

  .footer-copyright {
    padding: 16px 16px 24px;
  }

  .field-table th,
  .field-table td,
  .map-table th,
  .map-table td,
  .info-table th,
  .info-table td {
    padding: 9px 10px;
  }

  .field-table tbody th,
  .map-table tbody th,
  .info-table tbody th {
    width: 130px;
  }
}

@media (max-width: 480px) {
  .hero-metrics {
    grid-template-columns: minmax(0, 1fr);
  }

  .browse-steps .step-list,
  .index-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .guide-steps .step-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
  }

  .field-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
  }

  .channel-meta {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
  }

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

  .error-inner {
    padding: 24px 18px;
  }

  .field-table,
  .map-table,
  .info-table {
    font-size: 13px;
  }

  .field-table tbody th,
  .map-table tbody th,
  .info-table tbody th {
    width: 100px;
  }

  .page-title {
    font-size: 23px;
  }

  .hero-title {
    font-size: 23px;
  }
}