:root {
  --wrap: 1180px;
  --read: 720px;
  --paper: #FAF7F2;
  --card: #FFFFFF;
  --ink: #1F2023;
  --ink-soft: #5C6068;
  --line: #E4DED3;
  --bronze: #9A7B4F;
  --teal: #35605A;
  --alert: #B4553F;
  --stripe: #F1ECE3;
  --serif: "Noto Serif SC", "Songti SC", "SimSun", Georgia, serif;
  --sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

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

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

body.site-body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.8;
  font-variant-numeric: tabular-nums;
}

h1,
h2,
h3,
h4 {
  margin: 0 0 0.6em;
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.35;
  color: var(--ink);
}

h2 {
  font-size: clamp(1.375rem, 1.2rem + 0.6vw, 1.625rem);
}

h3 {
  font-size: 1.0625rem;
}

p {
  margin: 0 0 1em;
}

ul,
ol {
  margin: 0 0 1em;
  padding-left: 1.25em;
}

dl,
dd {
  margin: 0;
}

a {
  color: var(--ink);
  text-decoration: none;
  text-underline-offset: 3px;
}

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

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--bronze);
  outline-offset: 2px;
}

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

figure {
  margin: 0;
}

figcaption {
  margin-top: 0.65em;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

button {
  font: inherit;
  color: inherit;
}

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

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

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
}

.site-main {
  display: block;
}

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

.read {
  max-width: var(--read);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
  width: 100%;
}

.section {
  margin: 48px 0;
}

.section-head {
  margin-bottom: 22px;
  max-width: var(--read);
}

.section-head h2 {
  margin-bottom: 0.35em;
}

.section-desc,
.section-intro {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.section-intro {
  margin-bottom: 20px;
  max-width: var(--read);
}

/* 页头 */

.site-header {
  background: var(--card);
  border-bottom: 1px solid var(--line);
}

.site-header.is-stuck {
  position: sticky;
  top: 0;
  z-index: 40;
  box-shadow: 0 1px 0 var(--line);
}

.header-inner {
  padding-top: 14px;
  padding-bottom: 0;
}

.brand-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 18px;
  padding-bottom: 10px;
}

.brand {
  font-family: var(--serif);
  font-size: 1.375rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: 0;
  text-decoration: none;
}

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

.brand-slogan {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 8px 14px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 6px;
  cursor: pointer;
}

.nav-toggle-icon {
  display: block;
  width: 16px;
  height: 2px;
  background: var(--ink);
  position: relative;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: var(--ink);
}

.nav-toggle-icon::before {
  top: -5px;
}

.nav-toggle-icon::after {
  top: 5px;
}

.nav-toggle-text {
  font-size: 0.875rem;
}

.site-nav {
  border-top: 1px solid var(--line);
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-list li {
  flex: 0 0 auto;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  font-size: 0.9375rem;
  color: var(--ink-soft);
  border-bottom: 2px solid transparent;
  text-decoration: none;
}

.nav-link:hover {
  color: var(--ink);
  text-decoration: none;
  border-bottom-color: var(--line);
}

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

/* 面包屑与页面标题区 */

.breadcrumb {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 18px 24px 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

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

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

.breadcrumb-sep {
  margin: 0 8px;
  color: var(--line);
}

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

.page-header {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 18px 24px 0;
}

.page-title {
  margin: 0;
  font-size: clamp(1.75rem, 1.4rem + 1.2vw, 2.375rem);
  font-weight: 600;
  line-height: 1.35;
  color: var(--ink);
}

.page-head {
  padding-top: 14px;
  padding-bottom: 4px;
}

.page-lead {
  max-width: var(--read);
  margin: 0 0 8px;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-kicker {
  margin: 0 0 6px;
  font-size: 0.8125rem;
  color: var(--bronze);
}

.page-meta {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

/* 页脚 */

.site-footer {
  margin-top: 64px;
  padding: 40px 0 0;
  background: var(--card);
  border-top: 1px solid var(--line);
  font-size: 0.9375rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1.4fr);
  gap: 32px 48px;
  padding-bottom: 28px;
}

.footer-brand .brand {
  display: inline-block;
  margin-bottom: 10px;
}

.footer-desc {
  margin: 0 0 10px;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.footer-nav-note {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px 32px;
}

.footer-group-title {
  margin: 0 0 10px;
  font-family: var(--sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--ink);
}

.footer-group ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-group li {
  margin-bottom: 2px;
}

.footer-group a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 0.875rem;
  color: var(--ink-soft);
}

.footer-group a:hover {
  color: var(--bronze);
}

.footer-bottom {
  border-top: 1px solid var(--line);
  padding-top: 16px;
  padding-bottom: 20px;
}

.footer-bottom p {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

/* ============ components ============ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 22px;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: 6px;
  border: 1px solid transparent;
  text-decoration: none;
  transition: transform 0.15s ease, background-color 0.15s ease, border-color 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--teal);
  color: #FFFFFF;
  border-color: var(--teal);
}

.btn-primary:hover {
  background: #2b4f4a;
  color: #FFFFFF;
}

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line);
}

.btn-ghost:hover {
  border-color: var(--bronze);
  color: var(--bronze);
}

.btn-outline {
  background: transparent;
  color: var(--bronze);
  border-color: var(--bronze);
  white-space: nowrap;
}

.btn-outline:hover {
  background: var(--bronze);
  color: #FFFFFF;
}

.link-arrow,
.link-more,
.link-inline,
.text-link,
.path-link,
.entry-link,
.error-link {
  display: inline-block;
  font-size: 0.9375rem;
  color: var(--bronze);
  text-decoration: underline;
  text-decoration-thickness: 1px;
}

.link-arrow::after {
  content: " \2192";
  text-decoration: none;
}

.link-arrow:hover,
.link-more:hover,
.link-inline:hover,
.text-link:hover,
.path-link:hover,
.entry-link:hover,
.error-link:hover {
  color: var(--ink);
}

.tag,
.tag-direction,
.direction-tag {
  display: inline-block;
  padding: 2px 9px;
  font-family: var(--sans);
  font-size: 0.75rem;
  font-weight: 600;
  line-height: 1.6;
  border-radius: 3px;
  background: var(--teal);
  color: #FFFFFF;
}

.table-scroll {
  width: 100%;
  overflow-x: auto;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.data-table {
  width: 100%;
  min-width: 560px;
  font-size: 0.9375rem;
  text-align: left;
}

.data-table caption {
  padding: 14px 16px 0;
  text-align: left;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.data-table th,
.data-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  line-height: 1.7;
}

.data-table thead th {
  background: var(--stripe);
  font-family: var(--sans);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
}

.data-table tbody th {
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
}

.data-table tbody tr:nth-child(even) {
  background: var(--paper);
}

.data-table tbody tr:hover {
  background: var(--stripe);
}

.data-table tbody tr:last-child th,
.data-table tbody tr:last-child td {
  border-bottom: 0;
}

.table-note {
  margin: 10px 0 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

.table-caption {
  caption-side: top;
}

.related-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  max-width: var(--wrap);
  margin: 40px auto 0;
  padding: 18px 24px;
  border-top: 1px solid var(--line);
  font-size: 0.875rem;
}

.related-links-label {
  color: var(--ink-soft);
}

.related-links-item {
  color: var(--bronze);
  text-decoration: underline;
  text-decoration-thickness: 1px;
}

.related-links-item:hover {
  color: var(--ink);
}

/* ============ pages ============ */

/* 首页 */

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

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr);
  gap: 40px;
  align-items: start;
}

.hero-copy {
  padding-top: 6px;
}

.hero-eyebrow {
  margin: 0 0 12px;
  font-size: 0.8125rem;
  color: var(--bronze);
}

.hero-copy h1 {
  margin: 0 0 16px;
  font-size: clamp(2rem, 1.5rem + 2vw, 2.875rem);
  line-height: 1.3;
}

.hero-lead {
  margin: 0 0 22px;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

.hero-problems {
  margin-bottom: 26px;
  padding: 16px 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--bronze);
  border-radius: 6px;
}

.hero-problems-title {
  margin: 0 0 8px;
  font-family: var(--sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--ink);
}

.problem-list {
  margin: 0;
  padding-left: 1.15em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.problem-list li + li {
  margin-top: 4px;
}

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

.hero-figure {
  padding: 10px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.hero-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  height: auto;
  object-fit: cover;
  border-radius: 4px;
}

.hero-figure figcaption {
  padding: 0 4px;
}

.coverage,
.route,
.samples,
.meter,
.topic-brief,
.faq {
  padding: 44px 0 0;
}

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

.coverage-item {
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  transition: background-color 0.15s ease;
}

.coverage-item:hover {
  background: var(--paper);
}

.coverage-item h3 {
  margin-bottom: 8px;
}

.coverage-item p {
  margin-bottom: 12px;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.route-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.route-step {
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.route-num {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--serif);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--bronze);
}

.route-step h3 {
  margin-bottom: 6px;
  font-size: 1rem;
}

.route-step p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

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

.sample-card {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1fr);
  gap: 16px;
  align-items: stretch;
  padding: 14px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  transition: background-color 0.15s ease, transform 0.15s ease;
}

.sample-card:hover {
  background: var(--paper);
  transform: translateY(-2px);
}

.sample-media {
  margin: 0;
}

.sample-media img {
  width: 100%;
  height: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 4px;
}

.sample-body {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
  min-width: 0;
}

.sample-type {
  margin: 0;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink);
}

.sample-desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

.sample-body .link-arrow {
  margin-top: auto;
  font-size: 0.875rem;
}

.meter-table {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

.meter-row {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.4fr);
  gap: 16px;
  align-items: center;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
}

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

.meter-head {
  background: var(--stripe);
  font-size: 0.8125rem;
  font-weight: 600;
}

.meter-name {
  display: flex;
  align-items: center;
  font-size: 0.9375rem;
}

.meter-bar-label {
  display: block;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.meter-bar {
  display: block;
  height: 10px;
  background: var(--stripe);
  border-radius: 5px;
  overflow: hidden;
}

.meter-fill {
  display: block;
  height: 100%;
  background: var(--bronze);
  border-radius: 5px;
}

.meter-note {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

.meter-footnote {
  margin: 10px 0 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

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

.brief-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.brief-question {
  margin: 0;
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
}

.brief-conclusion {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.brief-card .link-arrow {
  margin-top: auto;
  font-size: 0.875rem;
}

.faq-list {
  display: grid;
  gap: 10px;
  max-width: 860px;
}

.faq-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.faq-item summary {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 12px 20px;
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.faq-item summary::before {
  content: "+";
  margin-right: 10px;
  font-family: var(--sans);
  color: var(--bronze);
}

.faq-item[open] summary::before {
  content: "\2212";
}

.faq-body {
  padding: 0 20px 16px 42px;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.faq-body p {
  margin-bottom: 10px;
}

.boundary {
  margin-top: 48px;
  padding: 32px 0;
  background: var(--card);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.boundary-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 20px 32px;
  padding-left: 24px;
  border-left: 3px solid var(--bronze);
}

.boundary-text {
  flex: 1 1 420px;
  min-width: 0;
}

.boundary-text h2 {
  margin-bottom: 8px;
  font-size: 1.25rem;
}

.boundary-text p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* 分类册 */

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

.direction-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.direction-card h3 {
  margin: 0;
}

.direction-text {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.direction-state {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--ink);
}

.direction-card .link-more {
  margin-top: auto;
  font-size: 0.875rem;
}

.threshold-table tbody th {
  font-family: var(--sans);
}

.compare-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.compare-figure {
  margin: 0;
  padding: 10px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.compare-figure img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 4px;
}

.entry-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

.entry-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  min-height: 56px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
}

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

.entry-row:hover {
  background: var(--paper);
}

.entry-row .direction-tag {
  flex: 0 0 auto;
}

.entry-desc {
  flex: 1 1 320px;
  min-width: 0;
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

.entry-row .link-more {
  flex: 0 0 auto;
  font-size: 0.875rem;
}

.entry-footnote {
  margin: 14px 0 0;
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.entry-footnote .link-inline {
  font-size: 0.8125rem;
}

/* 作品条目 */

.field-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

.field-item {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 20px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
}

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

.field-item dt {
  font-family: var(--sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--ink);
}

.field-item dd {
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.section-entries .entry-row {
  align-items: flex-start;
}

.entry-body {
  flex: 1 1 360px;
  min-width: 0;
}

.entry-title {
  margin: 0 0 4px;
  font-size: 1rem;
}

.entry-body .entry-desc {
  flex: none;
}

.entry-row .entry-link {
  flex: 0 0 auto;
  font-size: 0.875rem;
}

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

.path-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.path-card h3 {
  margin: 0;
}

.path-card p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.path-card .path-link {
  margin-top: auto;
  font-size: 0.875rem;
}

.figure-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.figure-item {
  margin: 0;
  padding: 10px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.figure-item img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 4px;
}

/* 专题讲读 */

.anchor-bar {
  margin-top: 20px;
  padding-top: 0;
  padding-bottom: 0;
}

.anchor-list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 8px;
  margin: 0;
  padding: 10px 0;
  list-style: none;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.anchor-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 10px;
  font-size: 0.875rem;
  color: var(--ink-soft);
  border-bottom: 2px solid transparent;
}

.anchor-link:hover {
  color: var(--bronze);
  text-decoration: none;
  border-bottom-color: var(--bronze);
}

.topic-section {
  margin: 44px 0;
}

.topic-section:first-child {
  margin-top: 32px;
}

.topic-figure {
  margin: 0 0 24px;
  padding: 10px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.topic-figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 4px;
}

.topic-split {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.topic-abstract h3,
.topic-questions h3 {
  margin-bottom: 8px;
  font-size: 1rem;
}

.topic-abstract p,
.topic-questions li {
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

.question-list {
  margin: 0;
  padding-left: 1.15em;
}

.question-list li + li {
  margin-top: 6px;
}

.method-steps {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: none;
}

.method-steps li {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 4px 14px;
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.method-steps .step-num {
  grid-row: span 2;
  font-family: var(--serif);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--bronze);
}

.method-steps h3 {
  margin: 0;
  font-size: 1rem;
}

.method-steps p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.record-fields {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr);
  gap: 0;
  margin: 0 0 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

.record-fields dt,
.record-fields dd {
  padding: 12px 18px;
  border-bottom: 1px solid var(--line);
  font-size: 0.9375rem;
  line-height: 1.75;
}

.record-fields dt {
  font-weight: 600;
  background: var(--paper);
}

.record-fields dd {
  color: var(--ink-soft);
}

.record-fields dt:nth-last-of-type(1),
.record-fields dd:nth-last-of-type(1) {
  border-bottom: 0;
}

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

.result-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.result-card h3 {
  margin: 0;
  font-size: 1rem;
}

.result-card p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.result-card .text-link {
  margin-top: auto;
  font-size: 0.875rem;
}

/* 人物与设定 */

.field-order-body {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: 32px;
  align-items: start;
}

.field-order .field-list {
  display: block;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: field;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

.field-order .field-item {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 16px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
}

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

.field-name {
  font-family: var(--sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--ink);
}

.field-note {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.field-figure {
  margin: 0;
  padding: 10px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.field-figure img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: 4px;
}

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

.relation-col {
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.relation-col h3 {
  margin-bottom: 8px;
  font-size: 1rem;
}

.relation-col p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.relation-col p + p {
  margin-top: 8px;
}

.term-table tbody th {
  font-family: var(--sans);
  white-space: normal;
}

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

.cross-col {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.cross-col h3 {
  margin: 0;
  font-size: 1rem;
}

.cross-col p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.cross-col .link-inline {
  margin-top: auto;
  font-size: 0.875rem;
}

/* 阅读帮助 */

.help-block {
  margin: 40px auto;
}

.help-list {
  display: grid;
  gap: 10px;
}

.help-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.help-item summary {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 13px 20px;
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.help-item summary::before {
  content: "+";
  margin-right: 10px;
  color: var(--bronze);
}

.help-item[open] summary::before {
  content: "\2212";
}

.help-body {
  padding: 0 20px 18px 42px;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

.help-body p {
  margin-bottom: 10px;
}

.step-list {
  margin: 0 0 10px;
  padding-left: 1.2em;
}

.step-list li + li {
  margin-top: 4px;
}

.boundary-block {
  padding: 28px 0;
  max-width: var(--wrap);
  background: var(--card);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.boundary-block .boundary-inner {
  display: block;
  flex: none;
  padding-left: 24px;
  border-left: 3px solid var(--bronze);
}

.boundary-block .boundary-text {
  flex: none;
}

.boundary-block .boundary-text p {
  margin: 0 0 10px;
}

.boundary-link {
  margin: 12px 0 0;
  font-size: 0.875rem;
}

/* 数据说明 */

.matrix-table {
  min-width: 640px;
}

.matrix-table tbody th {
  font-family: var(--sans);
  white-space: normal;
}

.matrix-figure {
  margin: 24px 0 0;
  padding: 10px;
  max-width: 720px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.matrix-figure img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 4px;
}

.source-list {
  margin: 0;
  padding-left: 1.2em;
  max-width: var(--read);
}

.source-list li {
  margin-bottom: 8px;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* 404 */

.error-main {
  padding: 56px 0 24px;
}

.error-inner {
  max-width: 860px;
}

.error-head {
  margin-bottom: 36px;
}

.error-code {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-size: 1rem;
  color: var(--bronze);
}

.error-head h1 {
  margin: 0 0 12px;
  font-size: clamp(1.75rem, 1.4rem + 1.2vw, 2.375rem);
}

.error-lead {
  margin: 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

.error-paths {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

.error-path {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.error-path h2 {
  margin: 0;
  font-size: 1rem;
}

.error-path p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.error-path .error-link {
  margin-top: auto;
  font-size: 0.875rem;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}

.error-note {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

/* 跳转链接 */

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 60;
  padding: 10px 16px;
  background: var(--card);
  border: 1px solid var(--bronze);
  border-radius: 6px;
  font-size: 0.875rem;
}

.skip-link:focus {
  top: 12px;
}

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

@media (max-width: 1024px) {
  .hero-grid {
    gap: 28px;
  }

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

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

  .meter-row {
    grid-template-columns: 120px minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.2fr);
    gap: 12px;
    padding: 12px 16px;
  }

  .field-order-body {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.7fr);
    gap: 24px;
  }

  .footer-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr);
    gap: 28px 36px;
  }
}

@media (max-width: 768px) {
  .wrap {
    padding: 0 18px;
  }

  .read {
    padding-left: 18px;
    padding-right: 18px;
  }

  .breadcrumb,
  .page-header {
    padding-left: 18px;
    padding-right: 18px;
  }

  .header-inner {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 10px;
    padding-top: 12px;
  }

  .brand-row {
    grid-column: 1;
    padding-bottom: 0;
    flex-direction: column;
    gap: 2px;
  }

  .nav-toggle {
    grid-column: 2;
    display: inline-flex;
  }

  .site-nav {
    grid-column: 1 / -1;
    border-top: 0;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    gap: 0;
    padding: 6px 0 10px;
    border-top: 1px solid var(--line);
  }

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

  .nav-link {
    width: 100%;
    padding: 0 4px;
    border-bottom: 1px solid var(--line);
  }

  .nav-link.is-current {
    border-bottom-color: var(--bronze);
  }

  .hero {
    padding-top: 28px;
  }

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

  .hero-figure {
    order: 2;
  }

  .coverage,
  .route,
  .samples,
  .meter,
  .topic-brief,
  .faq {
    padding-top: 36px;
  }

  .coverage-grid,
  .route-list,
  .direction-grid,
  .brief-grid,
  .path-grid,
  .result-grid,
  .relation-grid,
  .cross-grid,
  .error-paths,
  .figure-grid,
  .compare-grid {
    grid-template-columns: minmax(0, 1fr);
  }

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

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

  .sample-media img {
    aspect-ratio: 16 / 9;
  }

  .meter-head {
    display: none;
  }

  .meter-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 8px;
    padding: 16px;
  }

  .meter-bar-label {
    font-weight: 600;
  }

  .boundary-inner {
    padding-left: 18px;
  }

  .boundary-text {
    flex: 1 1 100%;
  }

  .entry-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .entry-desc,
  .entry-body {
    flex: 1 1 auto;
  }

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

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

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

  .field-figure img {
    aspect-ratio: 16 / 10;
  }

  .topic-split {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
  }

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

  .record-fields dt {
    padding-bottom: 4px;
    border-bottom: 0;
  }

  .record-fields dd {
    padding-top: 0;
  }

  .record-fields dt:nth-last-of-type(1),
  .record-fields dd:nth-last-of-type(1) {
    border-bottom: 1px solid var(--line);
  }

  .record-fields dd:nth-last-of-type(1) {
    border-bottom: 0;
  }

  .method-steps li {
    grid-template-columns: 36px minmax(0, 1fr);
    padding: 14px 16px;
  }

  .help-body {
    padding-left: 20px;
  }

  .boundary-block {
    padding: 24px 0;
  }

  .boundary-block .boundary-inner {
    padding-left: 18px;
  }

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

  .footer-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .site-footer {
    margin-top: 48px;
    padding-top: 28px;
  }

  .related-links {
    padding: 16px 18px;
  }
}

@media (max-width: 560px) {
  html {
    font-size: 15px;
  }

  .wrap {
    padding: 0 16px;
  }

  .read {
    padding-left: 16px;
    padding-right: 16px;
  }

  .breadcrumb,
  .page-header {
    padding-left: 16px;
    padding-right: 16px;
  }

  .brand {
    font-size: 1.25rem;
  }

  .brand-slogan {
    font-size: 0.75rem;
  }

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

  .hero-problems {
    padding: 14px 16px;
  }

  .hero-actions .btn {
    flex: 1 1 100%;
  }

  .coverage-item,
  .route-step,
  .direction-card,
  .brief-card,
  .path-card,
  .result-card,
  .relation-col,
  .cross-col,
  .error-path {
    padding: 16px;
  }

  .meter-fill {
    height: 8px;
  }

  .faq-item summary,
  .help-item summary {
    padding: 12px 16px;
  }

  .faq-body,
  .help-body {
    padding: 0 16px 14px 32px;
  }

  .boundary-inner {
    padding-left: 14px;
  }

  .boundary-block .boundary-inner {
    padding-left: 14px;
  }

  .footer-links {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .data-table {
    min-width: 520px;
    font-size: 0.875rem;
  }

  .data-table th,
  .data-table td {
    padding: 10px 12px;
  }

  .matrix-table {
    min-width: 560px;
  }

  .anchor-list {
    flex-wrap: nowrap;
    overflow-x: auto;
    gap: 0 4px;
  }

  .anchor-link {
    white-space: nowrap;
  }

  .entry-row {
    padding: 14px 16px;
  }

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

  .method-steps .step-num {
    grid-row: auto;
  }
}