:root {
  --ink: #1f3a4d;
  --ink-soft: #2f5468;
  --paper: #e8eef1;
  --panel: #f5f2ea;
  --line: #c9d6dc;
  --line-strong: #a9bcc5;
  --accent: #c8552f;
  --accent-soft: #f0d9d0;
  --mint: #3f7d6e;
  --mint-soft: #d6e6e0;
  --text: #4a4a4a;
  --text-soft: #6d7c85;
  --white: #ffffff;
  --radius: 6px;
  --radius-sm: 4px;
  --shadow: 0 1px 2px rgba(31, 58, 77, 0.08), 0 6px 18px rgba(31, 58, 77, 0.06);
  --wrap: 1180px;
  --gutter: 24px;
  --mono: "SFMono-Regular", "Menlo", "Consolas", "Liberation Mono", monospace;
}

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

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 92px;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--ink);
  text-decoration: none;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

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

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

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.35;
}

p {
  margin: 0;
}

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

figure {
  margin: 0;
}

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--ink);
  border-bottom: 3px solid var(--accent);
}

.header-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--gutter);
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding-right: 8px;
  font-size: 19px;
  font-weight: 700;
  color: var(--white);
  white-space: nowrap;
}

.brand::before {
  content: "";
  width: 10px;
  height: 10px;
  margin-right: 10px;
  background: var(--accent);
  border-radius: 2px;
  flex: none;
}

.brand:hover,
.brand:focus-visible {
  color: var(--accent-soft);
}

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

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

.nav-list li {
  display: flex;
}

.site-nav .nav-list a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  font-size: 15px;
  color: #d7e2e8;
  border-radius: var(--radius-sm);
}

.site-nav .nav-list a:hover,
.site-nav .nav-list a:focus-visible {
  color: var(--white);
  background: rgba(255, 255, 255, 0.1);
}

.site-nav .nav-list a.is-current {
  color: var(--white);
  background: var(--accent);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border-radius: var(--radius-sm);
}

.nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--white);
}

.nav-toggle:hover {
  background: rgba(255, 255, 255, 0.12);
}

.site-main {
  display: block;
}

.home-main,
.inner-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--gutter) 56px;
}

.site-footer {
  background: var(--ink);
  color: #c8d6dd;
  margin-top: 24px;
}

.footer-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 40px var(--gutter) 8px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 28px;
}

.footer-title {
  font-size: 15px;
  color: var(--white);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.18);
}

.footer-text {
  font-size: 14px;
  line-height: 1.85;
  color: #b6c7d0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  margin-top: 10px;
  font-size: 14px;
}

.footer-links a {
  color: #d7e2e8;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--accent-soft);
  border-bottom-color: var(--accent-soft);
}

.footer-copy {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 16px var(--gutter) 26px;
  font-size: 13px;
  color: #93a7b2;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

/* ============ shared inner page shell ============ */

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 18px 0 0;
  font-size: 14px;
  color: var(--text-soft);
}

.breadcrumb a {
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 1px;
}

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

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

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

.page-header {
  padding: 22px 0 26px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}

.page-title {
  font-size: 30px;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.32;
}

.page-description {
  margin-top: 12px;
  max-width: 880px;
  font-size: 16px;
  color: var(--text-soft);
}

.page-description a {
  color: var(--accent);
  border-bottom: 1px solid var(--accent-soft);
}

.page-description a:hover,
.page-description a:focus-visible {
  border-bottom-color: var(--accent);
}

.inner-main > section {
  margin-bottom: 44px;
}

.section-title {
  font-size: 22px;
  padding-left: 12px;
  border-left: 4px solid var(--accent);
}

.section-lead,
.section-intro {
  margin-top: 10px;
  font-size: 15px;
  color: var(--text-soft);
  max-width: 860px;
}

.section-lead a,
.section-intro a,
.section-note a,
.check-note a,
.mapping-note a,
.relations-note a {
  color: var(--accent);
  border-bottom: 1px solid var(--accent-soft);
}

.section-lead a:hover,
.section-intro a:hover,
.section-note a:hover,
.check-note a:hover,
.mapping-note a:hover,
.relations-note a:hover {
  border-bottom-color: var(--accent);
}

.section-note,
.check-note,
.mapping-note,
.relations-note {
  margin-top: 18px;
  font-size: 14px;
  color: var(--text-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}

/* ============ home: top note ============ */

.top-note {
  background: var(--ink-soft);
  color: #dbe6eb;
  font-size: 14px;
  text-align: center;
  padding: 10px var(--gutter);
  line-height: 1.6;
}

/* ============ home: editor picks ============ */

.editor-picks {
  padding: 34px 0 40px;
  border-bottom: 1px solid var(--line);
}

.site-title {
  font-size: 30px;
  color: var(--ink);
  line-height: 1.32;
}

.editor-picks-intro {
  margin-top: 12px;
  max-width: 880px;
  font-size: 16px;
  color: var(--text-soft);
}

.lead-story {
  margin-top: 26px;
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
  gap: 0;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.lead-figure {
  position: relative;
  min-height: 320px;
  background: var(--line);
}

.lead-figure img {
  width: 100%;
  height: 100%;
  min-height: 320px;
  object-fit: cover;
}

.lead-caption {
  position: absolute;
  left: 0;
  bottom: 0;
  right: 0;
  padding: 10px 14px;
  font-size: 13px;
  color: var(--white);
  background: rgba(31, 58, 77, 0.82);
}

.lead-body {
  padding: 26px 26px 28px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.lead-tag {
  display: inline-block;
  align-self: flex-start;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}

.lead-title {
  font-size: 23px;
  line-height: 1.4;
}

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

.lead-link {
  margin-top: 18px;
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 18px;
  font-size: 15px;
  font-weight: 700;
  color: var(--white);
  background: var(--accent);
  border-radius: var(--radius-sm);
}

.lead-link:hover,
.lead-link:focus-visible {
  color: var(--white);
  background: #a84525;
}

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

.sub-story {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr);
  gap: 16px;
  padding: 16px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.sub-figure {
  width: 140px;
  height: 110px;
  background: var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.sub-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.sub-title {
  font-size: 17px;
  line-height: 1.45;
}

.sub-text {
  margin-top: 8px;
  font-size: 14px;
  color: var(--text-soft);
  grid-column: 2;
}

.sub-link {
  grid-column: 2;
  margin-top: 10px;
  font-size: 14px;
  font-weight: 700;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  min-height: 32px;
}

.sub-link::after {
  content: "→";
  margin-left: 6px;
}

/* ============ home: sections shared head ============ */

.channel-glance,
.playlist-entries,
.browse-steps,
.field-boundary,
.log-glance,
.site-index {
  padding: 40px 0 0;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px 20px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--ink);
  margin-bottom: 22px;
}

.section-head h2 {
  font-size: 22px;
  padding-left: 12px;
  border-left: 4px solid var(--accent);
}

.section-desc {
  font-size: 14px;
  color: var(--text-soft);
  max-width: 620px;
}

.section-foot {
  margin-top: 18px;
  font-size: 14px;
}

.section-foot a {
  color: var(--accent);
  font-weight: 700;
  border-bottom: 1px solid var(--accent-soft);
  padding-bottom: 1px;
}

.section-foot a:hover,
.section-foot a:focus-visible {
  border-bottom-color: var(--accent);
}

/* ============ home: channel rows ============ */

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

.channel-row {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr) minmax(0, 1.2fr);
  gap: 18px;
  align-items: baseline;
  padding: 14px 12px;
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.channel-row:nth-child(even) {
  background: var(--panel);
}

.channel-code {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--accent);
}

.channel-dir {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.channel-scope {
  font-size: 14px;
  color: var(--text-soft);
}

/* ============ home: playlist cards ============ */

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

.playlist-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.playlist-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.playlist-figure {
  height: 150px;
  background: var(--line);
  overflow: hidden;
}

.playlist-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.playlist-name {
  font-size: 16px;
  padding: 14px 14px 0;
}

.playlist-channel {
  font-size: 13px;
  color: var(--text-soft);
  padding: 6px 14px 16px;
}

/* ============ home: browse steps ============ */

.browse-steps .step-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  counter-reset: browse;
}

.browse-steps .step-item {
  position: relative;
  padding: 20px 18px 18px;
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 3px solid var(--mint);
  border-radius: var(--radius);
}

.browse-steps .step-no {
  display: inline-block;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--mint);
  background: var(--mint-soft);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
}

.browse-steps .step-name {
  font-size: 17px;
}

.browse-steps .step-check {
  margin-top: 8px;
  font-size: 14px;
  color: var(--text-soft);
}

/* ============ home: field & boundary ============ */

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

.field-column,
.boundary-column {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 22px 24px;
}

.column-title {
  font-size: 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}

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

.field-item {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--line);
}

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

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

.field-desc {
  font-size: 14px;
  color: var(--text-soft);
}

.column-foot {
  margin-top: 16px;
  font-size: 14px;
}

.column-foot a {
  color: var(--accent);
  font-weight: 700;
}

.boundary-list {
  display: grid;
  gap: 12px;
}

.boundary-item {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  color: var(--text);
}

.boundary-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 2px;
}

/* ============ home: log glance ============ */

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

.log-month {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 18px 20px;
}

.month-name,
.log-month-name {
  font-size: 17px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--mint-soft);
  margin-bottom: 12px;
}

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

.log-item {
  display: grid;
  grid-template-columns: 72px 96px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  font-size: 14px;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--line);
}

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

.log-date {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--mint);
  font-weight: 700;
}

.log-scope {
  font-size: 13px;
  color: var(--ink-soft);
}

.log-note {
  color: var(--text-soft);
}

/* ============ home: site index ============ */

.index-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 16px;
}

.index-cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.18s ease, background-color 0.18s ease;
}

.index-cell:hover {
  border-color: var(--accent);
  background: var(--white);
}

.index-cell a {
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

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

.index-note {
  font-size: 13px;
  color: var(--text-soft);
  line-height: 1.6;
}

/* ============ channels page ============ */

.channel-map-figure {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.channel-map-figure img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
}

.channel-map-caption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--text-soft);
  border-top: 1px solid var(--line);
  background: var(--panel);
}

.channel-overview > .channel-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  background: var(--white);
  margin-top: 14px;
}

.channel-overview > .channel-row:nth-child(even) {
  background: var(--panel);
}

.channel-name {
  font-size: 17px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
}

.channel-name .channel-code {
  font-size: 13px;
  background: var(--accent-soft);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

.channel-direction {
  font-size: 15px;
  color: var(--text);
  max-width: 900px;
}

.channel-scope,
.channel-sample {
  font-size: 14px;
  color: var(--text-soft);
  max-width: 900px;
}

.channel-sample::before {
  content: "代表条目：";
  color: var(--ink-soft);
  font-weight: 700;
}

.compare-pair {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 16px;
}

.compare-col {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.compare-col:first-child {
  border-top: 3px solid var(--accent);
}

.compare-col:last-child {
  border-top: 3px solid var(--mint);
}

.compare-name {
  font-size: 16px;
  margin-bottom: 8px;
}

.compare-focus {
  font-size: 14px;
  color: var(--text-soft);
}

.map-table,
.catalog-table,
.relations-table,
.mapping-table {
  margin-top: 18px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.map-caption,
.table-caption {
  caption-side: top;
  text-align: left;
  padding: 12px 16px;
  font-size: 13px;
  color: var(--text-soft);
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}

.map-table th,
.map-table td,
.catalog-table th,
.catalog-table td,
.relations-table th,
.relations-table td,
.mapping-table th,
.mapping-table td {
  padding: 12px 16px;
  text-align: left;
  font-size: 14px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.map-table thead th,
.catalog-table thead th,
.relations-table thead th,
.mapping-table thead th {
  background: var(--ink);
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
}

.map-table tbody tr:nth-child(even),
.catalog-table tbody tr:nth-child(even),
.relations-table tbody tr:nth-child(even),
.mapping-table tbody tr:nth-child(even) {
  background: var(--panel);
}

.map-table tbody tr:last-child td,
.catalog-table tbody tr:last-child td,
.relations-table tbody tr:last-child td,
.mapping-table tbody tr:last-child td {
  border-bottom: 0;
}

.mapping-table tbody th {
  font-weight: 700;
  color: var(--ink);
  background: var(--mint-soft);
}

.channel-steps .step-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 18px;
}

.channel-steps .step-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 3px solid var(--mint);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.channel-steps .step-name {
  font-size: 16px;
}

.channel-steps .step-detail {
  margin-top: 8px;
  font-size: 14px;
  color: var(--text-soft);
}

/* ============ playlists page ============ */

.playlist-feature {
  margin-top: 4px;
}

.feature-figure {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.feature-figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.feature-caption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--text-soft);
  border-top: 1px solid var(--line);
  background: var(--panel);
}

.feature-meta {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.meta-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 16px;
}

.meta-item dt {
  font-size: 13px;
  color: var(--text-soft);
  margin-bottom: 6px;
}

.meta-item dd {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.feature-note {
  margin-top: 16px;
  font-size: 14px;
  color: var(--text-soft);
}

.feature-note a {
  color: var(--accent);
  font-weight: 700;
}

.notes-list {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.note-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.note-title {
  font-size: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 10px;
}

.note-text {
  font-size: 14px;
  color: var(--text-soft);
}

.rules-list {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  counter-reset: rules;
}

.rule-item {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px 18px 58px;
}

.rule-item::before {
  counter-increment: rules;
  content: counter(rules, decimal-leading-zero);
  position: absolute;
  left: 18px;
  top: 18px;
  font-family: var(--mono);
  font-size: 16px;
  font-weight: 700;
  color: var(--accent);
}

.rule-name {
  font-size: 16px;
}

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

/* ============ guide page ============ */

.guide-figure {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.guide-figure img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
}

.guide-figure figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--text-soft);
  border-top: 1px solid var(--line);
  background: var(--panel);
}

.guide-steps .step-list {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.guide-steps .step-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.guide-steps .step-index {
  display: inline-block;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--white);
  background: var(--accent);
  padding: 2px 9px;
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
}

.guide-steps .step-name {
  font-size: 16px;
}

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

.guide-steps .step-where {
  margin-top: 10px;
  font-size: 13px;
  color: var(--text-soft);
}

.guide-steps .step-where a {
  color: var(--accent);
  font-weight: 700;
}

.check-list {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.check-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.check-name {
  font-size: 16px;
  padding-left: 12px;
  border-left: 3px solid var(--mint);
}

.check-desc {
  margin-top: 8px;
  font-size: 14px;
  color: var(--text-soft);
}

.fallback-list {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.fallback-item {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.fallback-index {
  display: inline-block;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--mint);
  background: var(--mint-soft);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
}

.fallback-name {
  font-size: 16px;
}

.fallback-desc {
  margin-top: 8px;
  font-size: 14px;
  color: var(--text-soft);
}

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

.faq-question,
.faq-item summary {
  position: relative;
  padding: 15px 46px 15px 18px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
  min-height: 44px;
}

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

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

.faq-item[open] .faq-question::after,
.faq-item[open] summary::after {
  content: "−";
}

.faq-question:hover,
.faq-item summary:hover {
  background: var(--panel);
}

.faq-answer,
.faq-item p {
  padding: 0 18px 16px;
  font-size: 14px;
  color: var(--text-soft);
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.related-list {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
}

.related-item {
  display: flex;
}

.related-item a {
  flex: 1;
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.related-item a:hover,
.related-item a:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--white);
}

/* ============ fields page ============ */

.field-visual {
  margin-bottom: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.field-visual img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
}

.field-visual figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--text-soft);
  border-top: 1px solid var(--line);
  background: var(--panel);
}

.field-table h2,
.boundary h2,
.field-mapping h2,
.field-faq h2 {
  font-size: 22px;
  padding-left: 12px;
  border-left: 4px solid var(--accent);
}

.field-table .field-list {
  margin-top: 18px;
  display: grid;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.field-table .field-row {
  display: grid;
  grid-template-columns: 130px minmax(0, 1.3fr) minmax(0, 1fr);
  gap: 18px;
  align-items: baseline;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
}

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

.field-table .field-row:nth-child(even) {
  background: var(--panel);
}

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

.field-mean {
  font-size: 14px;
  color: var(--text);
}

.field-mean a {
  color: var(--accent);
  border-bottom: 1px solid var(--accent-soft);
}

.field-value {
  font-size: 13px;
  color: var(--text-soft);
}

.boundary .boundary-list {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.boundary .boundary-item {
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 16px 20px;
}

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

.boundary .boundary-item p {
  font-size: 14px;
  color: var(--text-soft);
}

.related-entry {
  margin-top: 44px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px 24px;
}

.related-entry h2 {
  font-size: 20px;
  padding-left: 12px;
  border-left: 4px solid var(--mint);
}

.related-entry p {
  margin-top: 10px;
  font-size: 14px;
  color: var(--text-soft);
}

.related-links {
  margin-top: 16px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.related-links li {
  display: flex;
}

.related-links a {
  flex: 1;
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

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

/* ============ log page ============ */

.log-figure {
  margin-bottom: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.log-figure img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
}

.log-figure figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--text-soft);
  border-top: 1px solid var(--line);
  background: var(--panel);
}

.log-months > .log-month {
  margin-top: 18px;
  padding: 20px 22px 22px;
}

.log-months .log-item {
  grid-template-columns: 78px 110px minmax(0, 1fr);
}

.log-text {
  font-size: 14px;
  color: var(--text-soft);
}

.type-grid {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.type-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.type-card:nth-child(1) {
  border-top: 3px solid var(--accent);
}

.type-card:nth-child(2) {
  border-top: 3px solid var(--mint);
}

.type-card:nth-child(3) {
  border-top: 3px solid var(--ink);
}

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

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

.impact-list {
  margin-top: 18px;
  display: grid;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
}

.impact-item {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 18px;
  align-items: baseline;
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
}

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

.impact-item:nth-child(even) {
  background: var(--panel);
}

.impact-name {
  font-size: 15px;
}

.impact-text {
  font-size: 14px;
  color: var(--text-soft);
}

.impact-text a {
  color: var(--accent);
  border-bottom: 1px solid var(--accent-soft);
}

.check-steps {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  counter-reset: logcheck;
}

.check-step {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px 18px 20px;
}

.check-step::before {
  counter-increment: logcheck;
  content: "0" counter(logcheck);
  display: block;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--mint);
  margin-bottom: 8px;
}

.check-step .check-name {
  font-size: 16px;
  padding-left: 0;
  border-left: 0;
}

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

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

.error-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 48px var(--gutter) 56px;
}

.error-panel {
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 34px 32px 36px;
  max-width: 760px;
}

.error-code {
  font-family: var(--mono);
  font-size: 46px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 14px;
}

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

.error-text {
  margin-top: 12px;
  font-size: 15px;
  color: var(--text-soft);
  max-width: 620px;
}

.error-actions {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 20px;
}

.error-button {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 20px;
  font-size: 15px;
  font-weight: 700;
  color: var(--white);
  background: var(--accent);
  border-radius: var(--radius-sm);
}

.error-button:hover,
.error-button:focus-visible {
  color: var(--white);
  background: #a84525;
}

.error-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  border-bottom: 1px solid var(--line-strong);
}

.error-link:hover,
.error-link:focus-visible {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.error-hints {
  margin-top: 36px;
  max-width: 900px;
}

.error-hints-title {
  font-size: 20px;
  padding-left: 12px;
  border-left: 4px solid var(--mint);
  margin-bottom: 16px;
}

.error-hint-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.error-hint-list li {
  display: flex;
}

.error-hint-list a {
  flex: 1;
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.error-hint-list a:hover,
.error-hint-list a:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--white);
}

/* ============ motion enhancement ============ */

@media (prefers-reduced-motion: no-preference) {
  .playlist-card,
  .index-cell,
  .related-item a,
  .related-links a,
  .error-hint-list a {
    transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease, color 0.18s ease;
  }
}

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

@media (max-width: 1080px) {
  .playlist-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

  .related-list,
  .related-links,
  .error-hint-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 900px) {
  .lead-story {
    grid-template-columns: minmax(0, 1fr);
  }

  .lead-figure,
  .lead-figure img {
    min-height: 240px;
  }

  .field-boundary-columns,
  .log-months,
  .notes-list,
  .channel-steps .step-list,
  .fallback-list,
  .type-grid,
  .check-steps,
  .check-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

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

@media (max-width: 768px) {
  :root {
    --gutter: 16px;
  }

  html {
    scroll-padding-top: 78px;
  }

  .header-inner {
    min-height: 58px;
    flex-wrap: wrap;
    padding-top: 6px;
    padding-bottom: 6px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    width: 100%;
    order: 3;
  }

  .nav-list {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 6px 0 10px;
  }

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

  .nav-list li {
    width: 100%;
  }

  .site-nav .nav-list a {
    width: 100%;
    min-height: 46px;
    padding: 0 14px;
    font-size: 16px;
  }

  .top-note {
    font-size: 13px;
    text-align: left;
  }

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

  .editor-picks {
    padding: 24px 0 30px;
  }

  .lead-body {
    padding: 20px 18px 22px;
  }

  .lead-title {
    font-size: 19px;
  }

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

  .sub-story {
    grid-template-columns: 110px minmax(0, 1fr);
  }

  .sub-figure {
    width: 110px;
    height: 92px;
  }

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

  .section-head h2,
  .section-title,
  .field-table h2,
  .boundary h2,
  .field-mapping h2,
  .field-faq h2 {
    font-size: 19px;
  }

  .channel-glance,
  .playlist-entries,
  .browse-steps,
  .field-boundary,
  .log-glance,
  .site-index {
    padding-top: 30px;
  }

  .channel-row {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: 6px 12px;
    padding: 12px 10px;
  }

  .channel-row .channel-scope {
    grid-column: 1 / -1;
  }

  .playlist-cards,
  .index-grid,
  .browse-steps .step-list,
  .guide-steps .step-list,
  .field-boundary-columns,
  .log-months,
  .notes-list,
  .channel-steps .step-list,
  .fallback-list,
  .type-grid,
  .check-steps,
  .check-list,
  .compare-pair,
  .feature-meta,
  .related-list,
  .related-links,
  .error-hint-list,
  .boundary .boundary-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .log-item,
  .log-months .log-item {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 4px 10px;
  }

  .log-item .log-note,
  .log-item .log-text {
    grid-column: 1 / -1;
  }

  .field-item {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 8px;
  }

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

  .map-table th,
  .map-table td,
  .catalog-table th,
  .catalog-table td,
  .relations-table th,
  .relations-table td,
  .mapping-table th,
  .mapping-table td {
    padding: 10px 12px;
    font-size: 13px;
  }

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
    padding-top: 30px;
  }

  .error-main {
    padding: 32px var(--gutter) 44px;
  }

  .error-panel {
    padding: 26px 20px 28px;
  }

  .error-code {
    font-size: 38px;
  }

  .error-title {
    font-size: 21px;
  }
}

@media (max-width: 420px) {
  .sub-story {
    grid-template-columns: minmax(0, 1fr);
  }

  .sub-figure {
    width: 100%;
    height: 150px;
  }

  .sub-text,
  .sub-link {
    grid-column: 1;
  }
}