:root {
  --color-page: #ffffff;
  --color-soft: #f5f6f8;
  --color-ink: #1f2430;
  --color-muted: #5a6270;
  --color-accent: #2f6df6;
  --color-mark: #e8543f;
  --color-line: #e6e9ef;
  --radius: 8px;
  --radius-sm: 6px;
  --container: 1160px;
  --gap: 24px;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Arial, sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", Consolas, "Liberation Mono", Menlo, monospace;
}

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

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

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

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

img {
  display: block;
  max-width: 100%;
  height: auto;
  border: 0;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.18s ease;
}

a:hover {
  color: var(--color-mark);
}

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

p {
  margin: 0;
}

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

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

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

time {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

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

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

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

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

.home-main,
.inner-main {
  display: block;
}

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

.home-main > section,
.inner-main > section {
  margin-top: 48px;
}

.home-main > section:first-child,
.inner-main > section:first-of-type {
  margin-top: 0;
}

/* ============================================================
   top hint
   ============================================================ */

.top-hint {
  margin: 0;
  padding: 10px 24px;
  background-color: var(--color-soft);
  border-bottom: 1px solid var(--color-line);
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.6;
  text-align: center;
}

/* ============================================================
   header / navigation
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background-color: var(--color-page);
  border-bottom: 1px solid var(--color-line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  max-width: var(--container);
  margin: 0 auto;
  padding: 14px 24px;
}

.brand {
  flex: 0 0 auto;
  font-size: 20px;
  font-weight: 600;
  color: var(--color-ink);
  white-space: nowrap;
}

.brand:hover {
  color: var(--color-accent);
}

.site-nav {
  display: block;
  flex: 1 1 auto;
}

.nav-list {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
  flex-wrap: wrap;
}

.nav-list li {
  display: block;
}

.nav-list a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  border-radius: var(--radius-sm);
  color: var(--color-ink);
  font-size: 15px;
  font-weight: 500;
}

.nav-list a:hover {
  background-color: var(--color-soft);
  color: var(--color-accent);
}

.nav-list a.is-current {
  color: var(--color-accent);
  background-color: rgba(47, 109, 246, 0.08);
}

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

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

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

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: 22px 0 0;
  font-size: 13px;
  color: var(--color-muted);
}

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

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

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

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

.page-header {
  padding: 20px 0 26px;
  border-bottom: 1px solid var(--color-line);
}

.page-title {
  font-size: 30px;
  font-weight: 600;
  color: var(--color-ink);
}

.page-description {
  margin-top: 12px;
  max-width: 760px;
  color: var(--color-muted);
  font-size: 15px;
  line-height: 1.8;
}

/* ============================================================
   shared section typography
   ============================================================ */

.home-main h2,
.inner-main h2 {
  font-size: 22px;
  font-weight: 600;
}

.section-lead,
.section-intro {
  margin-top: 10px;
  max-width: 820px;
  color: var(--color-muted);
  font-size: 15px;
  line-height: 1.8;
}

/* ============================================================
   components — tables
   ============================================================ */

.genre-table,
.topic-table {
  margin-top: 20px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
  font-size: 15px;
}

.genre-table thead th,
.topic-table thead th {
  padding: 12px 16px;
  background-color: var(--color-soft);
  border-bottom: 1px solid var(--color-line);
  text-align: left;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-muted);
  white-space: nowrap;
}

.genre-table tbody td,
.topic-table tbody td,
.topic-table tbody th {
  padding: 14px 16px;
  border-bottom: 1px solid var(--color-line);
  vertical-align: top;
  text-align: left;
  font-weight: 400;
  color: var(--color-ink);
}

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

.genre-table tbody tr:hover,
.topic-table tbody tr:hover {
  background-color: var(--color-soft);
}

.cell-num {
  width: 64px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--color-muted);
}

.cell-name {
  width: 150px;
  font-weight: 600;
}

.topic-table tbody th {
  width: 140px;
  font-weight: 600;
}

/* ============================================================
   components — field definition lists
   ============================================================ */

.field-list {
  margin-top: 12px;
  display: grid;
  grid-template-columns: minmax(96px, max-content) 1fr;
  gap: 8px 16px;
  font-size: 14px;
}

.field-list dt {
  font-weight: 600;
  color: var(--color-ink);
}

.field-list dd {
  margin: 0;
  color: var(--color-muted);
  line-height: 1.7;
}

/* ============================================================
   components — cards & lists
   ============================================================ */

.cover-wall {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 18px;
  margin-top: 20px;
}

.cover-card {
  display: flex;
  flex-direction: column;
  padding: 10px;
  background-color: var(--color-page);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.cover-card:hover {
  transform: translateY(-2px);
  border-color: var(--color-accent);
  box-shadow: 0 6px 16px rgba(31, 36, 48, 0.08);
}

.cover-card img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: var(--radius-sm);
  background-color: var(--color-soft);
}

.cover-name {
  margin-top: 10px;
  font-size: 15px;
  font-weight: 600;
}

.cover-meta {
  margin-top: 4px;
  color: var(--color-muted);
  font-size: 13px;
}

.update-list {
  margin-top: 18px;
  display: flex;
  flex-direction: column;
}

.update-item {
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 4px 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--color-line);
}

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

.update-date {
  grid-row: span 2;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.6;
}

.update-name {
  font-weight: 600;
  font-size: 15px;
}

.update-genre {
  color: var(--color-muted);
  font-size: 13px;
}

.update-change {
  grid-column: 2;
  color: var(--color-accent);
  font-size: 13px;
}

.update-more,
.rank-more {
  margin-top: 16px;
  font-size: 14px;
}

.rank-list {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--color-line);
}

.rank-item {
  display: grid;
  grid-template-columns: 48px 1fr 120px 1.4fr;
  align-items: center;
  gap: 12px;
  padding: 14px 4px;
  border-bottom: 1px solid var(--color-line);
  transition: background-color 0.18s ease;
}

.rank-item:hover {
  background-color: var(--color-soft);
}

.rank-num,
.rank-no {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-mark);
}

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

.rank-genre {
  color: var(--color-muted);
  font-size: 13px;
}

.rank-reason {
  color: var(--color-muted);
  font-size: 14px;
}

/* ============================================================
   components — related links
   ============================================================ */

.related-grid,
.related-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 20px;
}

.related-card,
.related-item {
  display: block;
  padding: 18px;
  background-color: var(--color-soft);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  transition: transform 0.18s ease, border-color 0.18s ease;
}

.related-card:hover,
.related-item:hover {
  transform: translateY(-2px);
  border-color: var(--color-accent);
}

.related-card h3,
.related-item h3 {
  font-size: 17px;
  font-weight: 600;
}

.related-card h3 a,
.related-item h3 a {
  color: var(--color-ink);
}

.related-card h3 a:hover,
.related-item h3 a:hover {
  color: var(--color-accent);
}

.related-card p,
.related-item p {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ============================================================
   components — footer
   ============================================================ */

.site-footer {
  margin-top: 56px;
  background-color: var(--color-soft);
  border-top: 1px solid var(--color-line);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.6fr repeat(3, 1fr);
  gap: 32px;
  max-width: var(--container);
  margin: 0 auto;
  padding: 44px 24px 32px;
}

.footer-brand {
  max-width: 320px;
}

.footer-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
}

.footer-desc {
  margin-top: 10px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.75;
}

.footer-group h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-ink);
}

.footer-group ul {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-group a {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  color: var(--color-muted);
  font-size: 14px;
}

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

.footer-bottom {
  max-width: var(--container);
  margin: 0 auto;
  padding: 18px 24px 28px;
  border-top: 1px solid var(--color-line);
  color: var(--color-muted);
  font-size: 13px;
}

/* ============================================================
   pages — home
   ============================================================ */

.hero-section {
  background-color: var(--color-soft);
  border-bottom: 1px solid var(--color-line);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 40px;
  max-width: var(--container);
  margin: 0 auto;
  padding: 52px 24px 56px;
}

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

.hero-title {
  font-size: 30px;
  font-weight: 600;
  line-height: 1.4;
}

.hero-lead {
  margin-top: 16px;
  max-width: 560px;
  color: var(--color-muted);
  font-size: 16px;
  line-height: 1.85;
}

.hero-entries {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-entries li {
  display: block;
}

.entry-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 20px;
  background-color: var(--color-page);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  color: var(--color-ink);
  font-size: 15px;
  font-weight: 500;
}

.entry-link:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

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

.hero-figure img {
  width: 100%;
  aspect-ratio: 16 / 11;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--color-line);
  background-color: var(--color-page);
}

.hero-figure figcaption {
  margin-top: 10px;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.6;
}

.genre-overview,
.wall-update,
.rank-section,
.boundary-section,
.column-index {
  max-width: var(--container);
  margin-left: auto;
  margin-right: auto;
  padding: 0 24px;
}

.wall-update {
  display: grid;
  grid-template-columns: 1.7fr 1fr;
  gap: 36px;
  align-items: start;
}

.wall-column {
  min-width: 0;
}

.update-column {
  min-width: 0;
  padding: 20px;
  background-color: var(--color-soft);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}

.boundary-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 20px;
}

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

.boundary-col h3 {
  font-size: 17px;
  font-weight: 600;
}

.boundary-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

.boundary-list li {
  position: relative;
  padding-left: 16px;
}

.boundary-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

.boundary-more {
  margin-top: 16px;
  font-size: 14px;
}

.index-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  margin-top: 20px;
}

.index-col {
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  transition: transform 0.18s ease, border-color 0.18s ease;
}

.index-col:hover {
  transform: translateY(-2px);
  border-color: var(--color-accent);
}

.index-col h3 {
  font-size: 16px;
  font-weight: 600;
}

.index-col h3 a {
  color: var(--color-ink);
}

.index-col h3 a:hover {
  color: var(--color-accent);
}

.index-col p {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.7;
}

/* ============================================================
   pages — topic (tese)
   ============================================================ */

.section-topic-table,
.section-topic-detail,
.section-topic-compare,
.section-related {
  margin-top: 44px;
}

.topic-block {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 28px;
  align-items: start;
  padding: 24px 0;
  border-bottom: 1px solid var(--color-line);
}

.topic-block:last-child {
  border-bottom: 0;
}

.topic-text {
  min-width: 0;
}

.topic-text h3 {
  font-size: 19px;
  font-weight: 600;
}

.topic-text p {
  margin-top: 10px;
  color: var(--color-muted);
  font-size: 15px;
  line-height: 1.8;
}

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

.topic-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--color-line);
  background-color: var(--color-soft);
}

.topic-figure figcaption {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.6;
}

.compare-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 20px;
}

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

.compare-col h3 {
  font-size: 17px;
  font-weight: 600;
}

.compare-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

.compare-list strong {
  color: var(--color-ink);
  font-weight: 600;
}

/* ============================================================
   pages — update archive (gengxin)
   ============================================================ */

.archive-visual .visual-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 20px;
}

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

.visual-figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--color-line);
  background-color: var(--color-soft);
}

.visual-figure figcaption {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.6;
}

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

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

.archive-month h3 {
  font-size: 18px;
  font-weight: 600;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-line);
}

.archive-list {
  margin-top: 4px;
  display: flex;
  flex-direction: column;
}

.archive-row {
  display: grid;
  grid-template-columns: 96px 1.4fr 110px 1.2fr;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--color-line);
  font-size: 14px;
}

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

.archive-row time {
  color: var(--color-muted);
  font-size: 13px;
}

.archive-name {
  font-weight: 600;
}

.archive-tag {
  color: var(--color-muted);
  font-size: 13px;
}

.archive-change {
  color: var(--color-accent);
  font-size: 13px;
}

.archive-summary .summary-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 20px;
}

.summary-item {
  min-width: 0;
  padding: 18px;
  background-color: var(--color-soft);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}

.summary-item h3 {
  font-size: 16px;
  font-weight: 600;
}

.summary-item p {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.7;
}

.archive-method .method-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 20px;
}

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

.method-col h3 {
  font-size: 17px;
  font-weight: 600;
}

.related-links .related-grid {
  margin-top: 20px;
}

/* ============================================================
   pages — ranking (paihang)
   ============================================================ */

.rank-section .rank-list {
  margin-top: 20px;
}

.rank-section .rank-item {
  grid-template-columns: 56px 96px 1fr;
  align-items: start;
  gap: 16px;
  padding: 16px 4px;
}

.rank-cover {
  margin: 0;
  min-width: 0;
}

.rank-cover img {
  width: 100%;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-line);
  background-color: var(--color-soft);
}

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

.rank-body .rank-name {
  font-size: 17px;
}

.rank-body .rank-name a {
  color: var(--color-ink);
}

.rank-body .rank-name a:hover {
  color: var(--color-accent);
}

.rank-meta {
  margin-top: 6px;
  color: var(--color-muted);
  font-size: 13px;
}

.rank-body .rank-reason {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.75;
}

.rank-footnote {
  margin-top: 16px;
  font-size: 14px;
}

.rank-explain .explain-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 24px;
  margin-top: 20px;
}

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

.explain-col h3 {
  font-size: 17px;
  font-weight: 600;
}

.explain-col p {
  margin-top: 10px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.75;
}

.explain-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

.explain-list li {
  position: relative;
  padding-left: 16px;
}

.explain-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

.explain-list strong {
  color: var(--color-ink);
  font-weight: 600;
}

.dimension-list {
  margin-top: 20px;
  display: grid;
  grid-template-columns: minmax(120px, max-content) 1fr;
  gap: 10px 20px;
  padding: 20px;
  background-color: var(--color-soft);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  font-size: 14px;
}

.dimension-list dt {
  font-weight: 600;
  color: var(--color-ink);
}

.dimension-list dd {
  margin: 0;
  color: var(--color-muted);
  line-height: 1.7;
}

.dimension-note {
  margin-top: 16px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

.dimension-note a {
  margin-right: 12px;
}

/* ============================================================
   pages — browse notes (shuoming)
   ============================================================ */

.field-section .field-layout {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 32px;
  align-items: start;
  margin-top: 20px;
}

.field-table {
  min-width: 0;
}

.field-row {
  padding: 16px 0;
  border-bottom: 1px solid var(--color-line);
}

.field-row:first-child {
  padding-top: 0;
}

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

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

.field-desc {
  margin-top: 6px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.75;
}

.field-sample {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-accent);
}

.field-aside {
  min-width: 0;
  padding: 18px;
  background-color: var(--color-soft);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}

.field-aside h3 {
  font-size: 16px;
  font-weight: 600;
}

.field-figure {
  margin: 12px 0 0;
}

.field-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-line);
  background-color: var(--color-page);
}

.field-figure figcaption {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 13px;
  line-height: 1.6;
}

.boundary-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 20px;
}

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

.flow-step {
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}

.flow-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background-color: rgba(47, 109, 246, 0.1);
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
}

.flow-name {
  margin-top: 12px;
  font-size: 16px;
  font-weight: 600;
}

.flow-desc {
  margin-top: 8px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.75;
}

.faq-list {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

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

.faq-item summary {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 14px 18px;
  background-color: var(--color-soft);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.faq-item summary::after {
  content: "+";
  margin-left: auto;
  padding-left: 12px;
  color: var(--color-muted);
  font-weight: 400;
}

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

.faq-item p {
  padding: 14px 18px 18px;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.8;
}

/* ============================================================
   pages — 404
   ============================================================ */

.error-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px 24px 64px;
}

.error-panel {
  padding: 36px 28px;
  background-color: var(--color-soft);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}

.error-code {
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 600;
  color: var(--color-mark);
  line-height: 1;
}

.error-panel h1 {
  margin-top: 12px;
  font-size: 26px;
  font-weight: 600;
}

.error-text {
  margin-top: 12px;
  max-width: 620px;
  color: var(--color-muted);
  font-size: 15px;
  line-height: 1.8;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 22px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
}

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

.btn-primary:hover {
  background-color: #2559d6;
  color: #ffffff;
}

.btn-ghost {
  border: 1px solid var(--color-line);
  background-color: var(--color-page);
  color: var(--color-ink);
}

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

.error-guide {
  margin-top: 40px;
}

.error-guide h2 {
  font-size: 20px;
  font-weight: 600;
}

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

.error-links a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  color: var(--color-ink);
  font-size: 14px;
}

.error-links a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ============================================================
   responsive — 1024
   ============================================================ */

@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 24px 44px;
  }

  .wall-update {
    grid-template-columns: 1fr;
    gap: 28px;
  }

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

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 28px;
  }

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

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

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

/* ============================================================
   responsive — 768
   ============================================================ */

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    padding: 12px 16px;
  }

  .brand {
    font-size: 18px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    flex: 1 0 100%;
  }

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

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

  .nav-list a {
    min-height: 44px;
    padding: 0 12px;
    justify-content: flex-start;
  }

  .home-main > section,
  .inner-main > section {
    margin-top: 36px;
  }

  .inner-main,
  .genre-overview,
  .wall-update,
  .rank-section,
  .boundary-section,
  .column-index,
  .error-main {
    padding-left: 16px;
    padding-right: 16px;
  }

  .inner-main {
    padding-bottom: 48px;
  }

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

  .home-main h2,
  .inner-main h2 {
    font-size: 19px;
  }

  .genre-table,
  .topic-table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
  }

  .genre-table thead th,
  .genre-table tbody td,
  .topic-table thead th,
  .topic-table tbody td,
  .topic-table tbody th {
    padding: 11px 12px;
  }

  .cover-wall {
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 14px;
  }

  .rank-item,
  .rank-section .rank-item {
    grid-template-columns: 40px 1fr;
    gap: 8px 12px;
  }

  .rank-genre,
  .rank-reason {
    grid-column: 2;
  }

  .rank-section .rank-item .rank-cover {
    grid-column: 1 / -1;
    max-width: 120px;
  }

  .rank-section .rank-item .rank-body {
    grid-column: 2;
  }

  .related-grid,
  .related-columns {
    grid-template-columns: 1fr;
  }

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

  .compare-columns,
  .boundary-columns,
  .boundary-layout,
  .archive-method .method-columns,
  .rank-explain .explain-grid,
  .field-section .field-layout,
  .archive-visual .visual-grid {
    grid-template-columns: 1fr;
  }

  .archive-row {
    grid-template-columns: 84px 1fr;
    gap: 6px 12px;
  }

  .archive-tag,
  .archive-change {
    grid-column: 2;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 16px 24px;
  }

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

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

  .error-code {
    font-size: 36px;
  }

  .error-panel h1 {
    font-size: 22px;
  }
}

/* ============================================================
   responsive — 480
   ============================================================ */

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }

  .top-hint {
    padding: 8px 16px;
    font-size: 12px;
    text-align: left;
  }

  .hero-entries {
    flex-direction: column;
    align-items: stretch;
  }

  .entry-link {
    justify-content: center;
  }

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

  .index-grid {
    grid-template-columns: 1fr;
  }

  .archive-summary .summary-grid,
  .flow-steps,
  .error-links {
    grid-template-columns: 1fr;
  }

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

  .update-date {
    grid-row: auto;
  }

  .update-change {
    grid-column: 1;
  }

  .field-list,
  .dimension-list {
    grid-template-columns: 1fr;
  }

  .field-list dt,
  .dimension-list dt {
    margin-top: 6px;
  }
}