:root {
  --paper: #f6f7f5;
  --ink: #1f2a37;
  --ink-soft: #4a5568;
  --ink-mute: #6b7280;
  --accent: #2f6f6a;
  --accent-dark: #245450;
  --region-1: #c96f4a;
  --region-2: #6a7fbf;
  --region-3: #b08b3e;
  --line: #d9dcd6;
  --line-strong: #b9bfb8;
  --panel: #ffffff;
  --shadow-sm: 0 1px 2px rgba(31, 42, 55, 0.06);
  --shadow-md: 0 4px 14px rgba(31, 42, 55, 0.08);
  --radius: 6px;
  --radius-sm: 4px;
  --wrap: 1180px;
  --gap: 24px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

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

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

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

body.site-body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

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

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

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

p {
  margin: 0;
}

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

figure {
  margin: 0;
}

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

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

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

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

.header-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
  min-height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.5px;
  white-space: nowrap;
}

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

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

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

.nav-link {
  display: inline-block;
  padding: 10px 14px;
  font-size: 15px;
  color: var(--ink-soft);
  border-bottom: 2px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

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

.nav-link.is-current {
  color: var(--ink);
  font-weight: 700;
  border-bottom-color: var(--accent);
}

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

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--ink);
  border-radius: 1px;
}

.site-main {
  display: block;
}

.inner-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px 56px;
}

.site-footer {
  background: var(--panel);
  border-top: 1px solid var(--line);
  margin-top: 40px;
}

.footer-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 40px 24px 24px;
}

.footer-index {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 28px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--line);
}

.footer-title {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--ink);
}

.footer-list li {
  margin-bottom: 8px;
}

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

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

.footer-bottom {
  padding-top: 18px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px;
}

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

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

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

.btn {
  display: inline-block;
  padding: 11px 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

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

.btn-primary:hover {
  background: var(--accent-dark);
  color: #fff;
}

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

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

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 18px 0 0;
  font-size: 13px;
  color: var(--ink-mute);
}

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

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

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

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

.page-header {
  padding: 22px 0 30px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 36px;
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 12px;
}

.page-description {
  font-size: 16px;
  color: var(--ink-soft);
  max-width: 820px;
}

.section {
  margin-bottom: 52px;
}

.section-head {
  margin-bottom: 22px;
}

.section-head h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

.section-head p {
  font-size: 15px;
  color: var(--ink-soft);
  max-width: 780px;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 10px;
}

.section-note,
.section-desc,
.section-intro {
  font-size: 15px;
  color: var(--ink-soft);
  max-width: 820px;
  margin-bottom: 24px;
}

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

.section-more a {
  font-weight: 600;
}

.panel-title {
  font-size: 16px;
  font-weight: 700;
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

/* ===== pages: index ===== */

.fact-bar {
  background: var(--ink);
  color: #e8ebe7;
}

.fact-bar p {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 8px 24px;
  font-size: 13px;
  letter-spacing: 0.2px;
}

.home-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px 56px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 40px;
  align-items: center;
  padding: 48px 0 56px;
}

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

.hero-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 1px;
  color: var(--accent);
  margin-bottom: 14px;
}

.hero-title {
  font-size: 34px;
  font-weight: 700;
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 16px;
  color: var(--ink-soft);
  margin-bottom: 26px;
  max-width: 520px;
}

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

.hero-media {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.hero-media img {
  width: 100%;
  height: 340px;
  object-fit: cover;
}

.hero-media figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--ink-mute);
  border-top: 1px solid var(--line);
}

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

.category-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) 168px;
  gap: 24px;
  align-items: center;
  padding: 20px 4px;
  border-bottom: 1px solid var(--line);
  transition: background 0.18s ease;
}

.category-row:hover {
  background: rgba(47, 111, 106, 0.04);
}

.category-no {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--region-2);
}

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

.category-name {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 6px;
}

.category-desc {
  font-size: 15px;
  color: var(--ink-soft);
  margin-bottom: 4px;
}

.category-reader {
  font-size: 13px;
  color: var(--ink-mute);
}

.category-cover {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--panel);
}

.category-cover img {
  width: 100%;
  height: 108px;
  object-fit: cover;
}

.category-cover figcaption {
  padding: 6px 10px;
  font-size: 12px;
  color: var(--ink-mute);
  border-top: 1px solid var(--line);
}

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

.update-group {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.update-time {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--line);
}

.update-list li + li {
  margin-top: 10px;
}

.update-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  font-size: 14px;
}

.update-name {
  font-weight: 600;
  color: var(--ink);
}

.update-tag {
  font-size: 12px;
  color: var(--region-1);
  border: 1px solid currentColor;
  border-radius: 3px;
  padding: 1px 6px;
}

.update-pos {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-mute);
  margin-left: auto;
}

.rank-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 32px;
}

.rank-panel,
.cover-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 22px;
}

.rank-list {
  counter-reset: none;
}

.rank-row {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
}

.rank-row:last-child {
  border-bottom: none;
}

.rank-no {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-mute);
}

.rank-row:nth-child(1) .rank-no {
  color: var(--region-1);
}

.rank-row:nth-child(2) .rank-no {
  color: var(--region-3);
}

.rank-row:nth-child(3) .rank-no {
  color: var(--region-2);
}

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

.rank-name {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
}

.rank-tag {
  font-size: 12px;
  color: var(--ink-mute);
}

.rank-reason {
  font-size: 13px;
  color: var(--ink-soft);
  margin-top: 3px;
}

.cover-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.cover-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--paper);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

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

.cover-card img {
  width: 100%;
  height: 118px;
  object-fit: cover;
}

.cover-card figcaption {
  padding: 7px 9px;
  font-size: 12px;
  color: var(--ink-soft);
  line-height: 1.4;
}

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

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

.step-no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  display: block;
  margin-bottom: 10px;
}

.step-name {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
}

.step-do,
.step-desc {
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 8px;
}

.step-result {
  font-size: 13px;
  color: var(--ink-mute);
  border-top: 1px dashed var(--line);
  padding-top: 8px;
}

.boundary-layout {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
}

.boundary-col {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.col-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.boundary-list li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 10px;
}

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

.index-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 18px;
}

.index-col {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  flex-direction: column;
}

.index-name {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
}

.index-desc {
  font-size: 13px;
  color: var(--ink-mute);
  margin-bottom: 14px;
  flex: 1;
}

.index-link {
  font-size: 14px;
  font-weight: 600;
}

/* ===== pages: categories ===== */

.cat-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 220px;
  gap: 28px;
  align-items: start;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

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

.cat-no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--region-2);
  display: block;
  margin-bottom: 8px;
}

.cat-name {
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 10px;
}

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

.cat-fit {
  font-size: 13px;
  color: var(--ink-mute);
  margin-bottom: 12px;
}

.cat-link {
  font-size: 14px;
  font-weight: 600;
}

.cat-cover {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--panel);
}

.cat-cover img {
  width: 100%;
  height: 150px;
  object-fit: cover;
}

.cat-cover-cap {
  padding: 8px 10px;
  font-size: 12px;
  color: var(--ink-mute);
  border-top: 1px solid var(--line);
}

.diff-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
}

.diff-col {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.diff-subtitle {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.diff-list li {
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 12px;
  padding-left: 16px;
  position: relative;
}

.diff-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--region-2);
}

.diff-list strong {
  color: var(--ink);
  display: block;
  margin-bottom: 2px;
}

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

.related-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

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

.related-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.related-desc {
  font-size: 13px;
  color: var(--ink-mute);
}

/* ===== pages: updates ===== */

.updates-section,
.clue-section,
.field-section,
.related-section {
  margin-bottom: 48px;
}

.update-group {
  margin-bottom: 26px;
}

.update-group-title {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--accent);
  padding-bottom: 10px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.update-row {
  display: grid;
  grid-template-columns: 108px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  transition: background 0.18s ease;
}

.update-row:hover {
  background: rgba(47, 111, 106, 0.04);
}

.update-thumb {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--panel);
}

.update-thumb img {
  width: 100%;
  height: 68px;
  object-fit: cover;
}

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

.update-title {
  display: block;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 4px;
}

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

.update-meta {
  font-size: 13px;
  color: var(--ink-mute);
}

.update-time {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--ink-mute);
  white-space: nowrap;
}

.clue-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
}

.clue-col {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.clue-col-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.clue-col p {
  font-size: 14px;
  color: var(--ink-soft);
}

.clue-col p + p {
  margin-top: 10px;
}

.field-table,
.standard-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.field-caption,
.table-caption {
  caption-side: top;
  text-align: left;
  padding: 0 0 12px;
  font-size: 13px;
  color: var(--ink-mute);
}

.field-table th,
.field-table td,
.standard-table th,
.standard-table td {
  padding: 13px 18px;
  font-size: 14px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.field-table thead th,
.standard-table thead th {
  background: var(--paper);
  font-size: 13px;
  font-weight: 700;
  color: var(--ink);
  white-space: nowrap;
}

.field-table tbody th {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--accent);
  white-space: nowrap;
  width: 180px;
}

.field-table tbody tr:last-child th,
.field-table tbody tr:last-child td,
.standard-table tbody tr:last-child td {
  border-bottom: none;
}

.field-desc,
.standard-table td {
  color: var(--ink-soft);
}

.field-name {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--accent);
  white-space: nowrap;
  width: 180px;
}

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

.related-item {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
  transition: border-color 0.18s ease, transform 0.18s ease;
}

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

.related-item a {
  font-size: 15px;
  font-weight: 700;
}

.related-note,
.related-desc {
  font-size: 13px;
  color: var(--ink-mute);
  margin-top: 6px;
}

/* ===== pages: guide ===== */

.guide-visual,
.guide-steps,
.guide-storage,
.guide-faq,
.related-links {
  margin-bottom: 48px;
}

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

.guide-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
}

.figure-caption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--ink-mute);
  border-top: 1px solid var(--line);
}

.guide-steps .step-item {
  border-top-color: var(--region-2);
}

.guide-steps .step-name {
  margin-bottom: 10px;
}

.step-action {
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 8px;
}

.two-col {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
}

.col-block {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.col-list li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 10px;
}

.col-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--region-3);
}

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

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

.faq-question {
  padding: 16px 44px 16px 18px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  position: relative;
  list-style: none;
}

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

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

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

.faq-answer {
  padding: 0 18px 18px;
}

.faq-answer p {
  font-size: 14px;
  color: var(--ink-soft);
}

.related-link {
  font-size: 15px;
  font-weight: 700;
}

/* ===== pages: boundaries ===== */

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

.scope-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
  margin-bottom: 28px;
}

.scope-col {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.scope-include {
  border-top: 3px solid var(--accent);
}

.scope-exclude {
  border-top: 3px solid var(--region-1);
}

.scope-list li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 10px;
}

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

.scope-exclude .scope-list li::before {
  background: var(--region-1);
}

.scope-figure {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--panel);
}

.scope-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.scope-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--ink-mute);
  border-top: 1px solid var(--line);
}

.feedback-columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.feedback-col {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
}

.col-text {
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 14px;
}

.feedback-list li {
  font-size: 13px;
  color: var(--ink-mute);
  padding-left: 16px;
  position: relative;
  margin-bottom: 8px;
}

.feedback-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--region-2);
}

/* ===== pages: 404 ===== */

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

.error-block {
  max-width: 620px;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 2px;
  color: var(--accent);
  margin-bottom: 14px;
}

.error-title {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 16px;
}

.error-text {
  font-size: 16px;
  color: var(--ink-soft);
  margin-bottom: 24px;
}

.error-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 28px;
}

.error-links a {
  padding: 9px 16px;
  font-size: 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  color: var(--ink);
  background: var(--panel);
}

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

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

@media (max-width: 960px) {
  .footer-index {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
    padding: 36px 0 44px;
  }

  .hero-title {
    font-size: 30px;
  }

  .hero-media img {
    height: 280px;
  }

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

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

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

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

  .cat-row {
    grid-template-columns: minmax(0, 1fr) 180px;
    gap: 22px;
  }

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

@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
    min-height: 58px;
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: flex;
  }

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

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
    padding: 6px 0 12px;
    border-top: 1px solid var(--line);
  }

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

  .nav-link {
    display: block;
    padding: 13px 4px;
    min-height: 44px;
    border-bottom: 1px solid var(--line);
  }

  .nav-link.is-current {
    border-bottom-width: 1px;
    border-bottom-color: var(--line);
    color: var(--accent);
  }

  .fact-bar p {
    padding: 8px 16px;
    font-size: 12px;
  }

  .home-main,
  .inner-main {
    padding: 0 16px 44px;
  }

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

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

  .page-header {
    padding: 18px 0 24px;
    margin-bottom: 28px;
  }

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

  .section {
    margin-bottom: 40px;
  }

  .section-head h2,
  .section-title {
    font-size: 19px;
  }

  .category-row {
    grid-template-columns: 40px minmax(0, 1fr);
    gap: 14px;
    padding: 18px 0;
  }

  .category-cover {
    grid-column: 1 / -1;
    max-width: 220px;
  }

  .category-cover img {
    height: 120px;
  }

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

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

  .cover-card img {
    height: 132px;
  }

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

  .boundary-layout,
  .diff-columns,
  .clue-columns,
  .two-col,
  .scope-columns {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
  }

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

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

  .cat-cover {
    max-width: 240px;
  }

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

  .update-row {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 14px;
    align-items: start;
  }

  .update-time {
    grid-column: 2;
    justify-self: start;
  }

  .update-thumb img {
    height: 60px;
  }

  .field-table tbody th,
  .field-name {
    width: auto;
    white-space: normal;
  }

  .field-table th,
  .field-table td,
  .standard-table th,
  .standard-table td {
    padding: 11px 14px;
  }

  .guide-figure img,
  .scope-figure img {
    height: 200px;
  }

  .footer-inner {
    padding: 32px 16px 20px;
  }

  .footer-index {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
  }

  .error-main {
    padding: 44px 16px 60px;
  }

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

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

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

  .rank-panel,
  .cover-panel,
  .category-row {
    padding-left: 14px;
    padding-right: 14px;
  }

  .hero-actions .btn {
    width: 100%;
    text-align: center;
  }
}

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

  * {
    transition: none !important;
  }
}