:root {
  --color-primary: #F5A623;
  --color-primary-dark: #D98B0F;
  --color-secondary: #3B82F6;
  --color-secondary-dark: #2563EB;
  --color-bg: #FFFDF8;
  --color-surface: #FFFFFF;
  --color-text: #2D3748;
  --color-muted: #718096;
  --color-border: #E2E8F0;
  --color-tint: #FEF6E7;
  --color-tint-blue: #EFF6FF;
  --radius: 8px;
  --radius-sm: 6px;
  --shadow-sm: 0 1px 2px rgba(45, 55, 72, 0.06);
  --shadow-md: 0 4px 12px rgba(45, 55, 72, 0.08);
  --shadow-lg: 0 10px 24px rgba(45, 55, 72, 0.12);
  --container: 1080px;
  --gap: 24px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

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

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

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0 0 0.6em;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-text);
}

p {
  margin: 0 0 1em;
}

p:last-child {
  margin-bottom: 0;
}

ul,
ol {
  margin: 0 0 1em;
  padding: 0;
  list-style: none;
}

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

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

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

figure {
  margin: 0;
}

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

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

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

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

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

.site-main {
  flex: 1 0 auto;
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

.inner-main {
  padding-top: 24px;
  padding-bottom: 56px;
}

.home-main {
  padding-bottom: 56px;
}

/* ---- header ---- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  width: 100%;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 12px 20px;
  min-height: 64px;
}

.brand-logo {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0;
  padding: 6px 0;
  min-height: 44px;
}

.brand-logo:hover {
  color: var(--color-primary-dark);
}

.brand-logo::before {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 8px;
  border-radius: 50%;
  background-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-tint);
}

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

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-item {
  margin: 0;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 8px 14px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background-color 0.18s ease, color 0.18s ease;
}

.nav-link:hover {
  background-color: var(--color-tint);
  color: var(--color-primary-dark);
}

.nav-link.is-current {
  color: var(--color-primary-dark);
  background-color: var(--color-tint);
  font-weight: 600;
}

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

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background-color: var(--color-text);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* ---- footer ---- */

.site-footer {
  width: 100%;
  margin-top: auto;
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 32px;
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px 20px 28px;
}

.footer-brand {
  flex: 1 1 260px;
  max-width: 420px;
}

.footer-name {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
}

.footer-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-muted);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 48px;
}

.footer-col {
  min-width: 132px;
}

.footer-col-title {
  margin: 0 0 12px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
}

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

.footer-list li {
  margin-bottom: 6px;
}

.footer-list a {
  display: inline-block;
  padding: 4px 0;
  font-size: 14px;
  color: var(--color-muted);
}

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

.footer-bottom {
  width: 100%;
  border-top: 1px solid var(--color-border);
}

.footer-copy {
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px 20px 24px;
  font-size: 13px;
  color: var(--color-muted);
}

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

/* ---- buttons ---- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}

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

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #FFFFFF;
  transform: translateY(-1px);
}

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

.btn-ghost:hover {
  background-color: var(--color-tint);
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
  transform: translateY(-1px);
}

/* ---- text link ---- */

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.text-link::after {
  content: "→";
  font-size: 14px;
  transition: transform 0.18s ease;
}

.text-link:hover {
  color: var(--color-primary-dark);
}

.text-link:hover::after {
  transform: translateX(3px);
}

/* ---- section scaffolding ---- */

.section {
  padding: 40px 0;
}

.section-inner {
  width: 100%;
}

.section-head {
  margin-bottom: 24px;
}

.section-title {
  margin: 0 0 8px;
  font-size: 24px;
  font-weight: 700;
  color: var(--color-text);
}

.section-desc {
  margin: 0;
  font-size: 15px;
  color: var(--color-muted);
}

.section-intro,
.section-lead {
  margin: 0 0 20px;
  font-size: 15px;
  color: var(--color-muted);
  max-width: 760px;
}

.section-foot {
  margin: 20px 0 0;
}

.section-note {
  margin: 16px 0 0;
  font-size: 14px;
  color: var(--color-muted);
}

.section-media {
  margin: 0 0 24px;
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-tint);
  border: 1px solid var(--color-border);
}

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

.section-media figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

/* ---- breadcrumb ---- */

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 4px 0 16px;
  font-size: 14px;
  color: var(--color-muted);
}

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

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

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

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 500;
}

/* ---- page header ---- */

.page-header {
  padding-bottom: 24px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--color-border);
}

.page-title {
  margin: 0 0 12px;
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

.page-description {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-muted);
  max-width: 820px;
}

/* ---- timeline (shared) ---- */

.timeline-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 2px solid var(--color-border);
}

.timeline-item {
  position: relative;
  padding: 0 0 20px 20px;
}

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

.timeline-item::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 8px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 2px solid var(--color-surface);
}

.timeline-date {
  display: block;
  margin-bottom: 4px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.timeline-text {
  margin: 0;
  font-size: 15px;
  color: var(--color-text);
}

/* ---- related links (shared) ---- */

.related-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.related-item {
  padding: 16px 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: box-shadow 0.18s ease, transform 0.18s ease;
}

.related-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.related-link {
  display: block;
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.related-desc {
  display: block;
  font-size: 14px;
  color: var(--color-muted);
}

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

/* ---- index: hero ---- */

.section-hero {
  padding: 32px 0 40px;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 32px;
  align-items: start;
}

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

.hero-title {
  margin: 0 0 16px;
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

.hero-lead {
  margin: 0 0 10px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
}

.hero-note {
  margin: 0 0 20px;
  font-size: 14px;
  color: var(--color-muted);
}

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

.hero-media {
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-tint);
  border: 1px solid var(--color-border);
}

.hero-media img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.hero-media figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.hero-needs {
  grid-column: 1 / -1;
  margin-top: 8px;
  padding: 22px 24px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius);
}

.hero-needs-title {
  margin: 0 0 14px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

.need-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 10px 24px;
}

.need-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px dashed var(--color-border);
}

.need-item:last-child {
  border-bottom: none;
}

.need-text {
  font-size: 15px;
  color: var(--color-text);
  min-width: 0;
}

.need-link {
  flex-shrink: 0;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-secondary-dark);
  padding: 4px 0;
}

.need-link:hover {
  color: var(--color-primary-dark);
}

/* ---- index: channels ---- */

.channel-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-surface);
}

.channel-row {
  display: grid;
  grid-template-columns: minmax(140px, 0.8fr) minmax(0, 1.2fr) minmax(0, 1.4fr);
  gap: 16px;
  align-items: center;
  padding: 16px 20px;
  border-bottom: 1px solid var(--color-border);
  transition: background-color 0.18s ease;
}

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

.channel-row:hover {
  background-color: var(--color-tint);
}

.channel-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
}

.channel-tone {
  font-size: 14px;
  color: var(--color-muted);
}

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

/* ---- index: collections ---- */

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

.collection-card {
  display: flex;
  flex-direction: column;
  padding: 22px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: box-shadow 0.18s ease, transform 0.18s ease;
}

.collection-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.collection-name {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

.collection-scope {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text);
}

.collection-channel {
  margin: 0 0 16px;
  font-size: 13px;
  color: var(--color-muted);
}

.card-link {
  margin-top: auto;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.card-link:hover {
  color: var(--color-primary-dark);
}

/* ---- index: field table ---- */

.field-table {
  width: 100%;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  font-size: 15px;
}

.field-caption {
  padding: 12px 20px;
  text-align: left;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-muted);
  background-color: var(--color-tint);
  border-bottom: 1px solid var(--color-border);
}

.field-table thead th {
  padding: 12px 20px;
  text-align: left;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  background-color: var(--color-tint-blue);
  border-bottom: 1px solid var(--color-border);
}

.field-table tbody th {
  padding: 14px 20px;
  text-align: left;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

.field-table tbody td {
  padding: 14px 20px;
  font-size: 14px;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
  line-height: 1.7;
}

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

.field-table tbody tr:hover {
  background-color: var(--color-tint);
}

/* ---- index: path list ---- */

.path-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.path-step {
  display: flex;
  flex-direction: column;
  padding: 22px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.step-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  margin-bottom: 12px;
  font-size: 15px;
  font-weight: 700;
  color: #FFFFFF;
  background-color: var(--color-secondary);
  border-radius: 50%;
}

.step-name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
}

.step-desc {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text);
}

.step-link {
  margin-top: auto;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.step-link:hover {
  color: var(--color-primary-dark);
}

/* ---- index: updates & feedback ---- */

.update-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 2px solid var(--color-border);
}

.update-item {
  position: relative;
  padding: 0 0 18px 20px;
}

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

.update-item::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 8px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 2px solid var(--color-surface);
}

.update-date {
  display: block;
  margin-bottom: 4px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.update-text {
  margin: 0;
  font-size: 15px;
  color: var(--color-text);
}

.feedback-block {
  margin-top: 28px;
  padding: 22px 24px;
  background-color: var(--color-tint);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.feedback-title {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

.feedback-text {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
}

.feedback-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin: 0;
}

/* ---- channels page ---- */

.section-channels .section-note a {
  font-weight: 600;
}

.channel-table {
  display: block;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-surface);
}

.channel-row.channel-row-head {
  background-color: var(--color-tint-blue);
  font-weight: 600;
  font-size: 14px;
}

.channel-row.channel-row-head .channel-cell {
  color: var(--color-text);
}

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

.channel-cell-name {
  font-weight: 600;
  color: var(--color-text);
}

.channel-cell-theme {
  color: var(--color-muted);
}

.channel-cell-use {
  color: var(--color-text);
}

/* ---- channels page: relation table ---- */

.relation-table {
  display: block;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-surface);
}

.relation-row {
  display: grid;
  grid-template-columns: minmax(160px, 0.9fr) minmax(0, 1.6fr);
  gap: 16px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--color-border);
  align-items: center;
}

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

.relation-row-head {
  background-color: var(--color-tint-blue);
  font-size: 14px;
  font-weight: 600;
}

.relation-cell {
  min-width: 0;
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
}

.relation-cell-channel {
  font-weight: 600;
}

.relation-cell-collection {
  color: var(--color-muted);
}

/* ---- channels page: feedback list ---- */

.feedback-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.feedback-item {
  padding: 16px 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-secondary);
  border-radius: var(--radius);
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
}

/* ---- collections page ---- */

.section-collection-visual .section-title {
  margin-bottom: 18px;
}

.collection-figure {
  margin: 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background-color: var(--color-tint);
}

.collection-figure img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.figure-caption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

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

.collection-meta {
  margin: 12px 0 0;
  padding: 0;
  font-size: 14px;
}

.collection-meta .meta-label {
  margin: 0;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-muted);
}

.collection-meta .meta-value {
  margin: 0 0 10px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text);
}

.collection-meta .meta-value:last-child {
  margin-bottom: 0;
}

/* ---- collections page: comparison ---- */

.comparison-table {
  display: block;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-surface);
}

.comparison-row {
  display: grid;
  grid-template-columns: minmax(140px, 0.9fr) minmax(0, 1.4fr) minmax(0, 1.4fr);
  gap: 16px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--color-border);
  align-items: center;
}

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

.comparison-head {
  background-color: var(--color-tint-blue);
  font-size: 14px;
  font-weight: 600;
}

.comparison-cell {
  min-width: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text);
}

.comparison-head .comparison-cell {
  color: var(--color-text);
}

/* ---- field-guide page ---- */

.field-overview,
.field-relation,
.field-updates,
.field-related {
  padding: 32px 0;
  border-bottom: 1px solid var(--color-border);
}

.field-related {
  border-bottom: none;
}

.field-figure {
  margin: 0 0 24px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background-color: var(--color-tint);
}

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

.field-layout {
  display: grid;
  grid-template-columns: minmax(220px, 260px) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.field-index {
  position: sticky;
  top: 88px;
  padding: 18px 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.field-index-title {
  margin: 0 0 12px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
}

.field-index-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: field-counter;
}

.field-index-item {
  counter-increment: field-counter;
  margin-bottom: 6px;
}

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

.field-index-item a {
  display: inline-block;
  padding: 4px 0;
  font-size: 14px;
  color: var(--color-muted);
}

.field-index-item a::before {
  content: counter(field-counter) ". ";
  color: var(--color-primary-dark);
  font-weight: 600;
}

.field-index-item a:hover {
  color: var(--color-primary-dark);
}

.field-list {
  display: grid;
  gap: 20px;
  min-width: 0;
}

.field-item {
  padding: 20px 22px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  scroll-margin-top: 88px;
}

.field-name {
  margin: 0 0 12px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

.field-meta {
  margin: 0;
  padding: 0;
}

.field-meta .field-term {
  margin: 0 0 4px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.field-meta .field-desc {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--color-text);
}

.field-meta .field-desc:last-child {
  margin-bottom: 0;
}

/* ---- field-guide page: relation & updates ---- */

.field-relation .relation-table {
  margin-top: 4px;
}

.field-relation .relation-row {
  grid-template-columns: minmax(160px, 0.9fr) minmax(0, 1.6fr);
}

.field-updates .update-timeline {
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 2px solid var(--color-border);
}

.field-updates .update-item {
  position: relative;
  padding: 0 0 18px 20px;
}

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

.field-updates .update-item::before {
  content: "";
  position: absolute;
  left: -6px;
  top: 8px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: 2px solid var(--color-surface);
}

.field-updates .update-date {
  display: block;
  margin-bottom: 4px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.field-updates .update-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
}

/* ---- browse-path page ---- */

.path-steps,
.path-faq,
.path-feedback,
.path-related {
  padding: 32px 0;
  border-bottom: 1px solid var(--color-border);
}

.path-related {
  border-bottom: none;
}

.path-figure {
  margin: 0 0 24px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background-color: var(--color-tint);
}

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

.step-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 16px;
}

.step-item {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 20px 22px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

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

.step-list .step-index {
  width: 40px;
  height: 40px;
  margin-bottom: 0;
  font-size: 16px;
  background-color: var(--color-primary);
}

.step-list .step-name {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

.step-list .step-desc {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
}

.step-entry {
  margin: 0;
}

.step-entry a {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-secondary-dark);
}

.step-entry a:hover {
  color: var(--color-primary-dark);
}

/* ---- browse-path page: FAQ ---- */

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

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

.faq-question {
  position: relative;
  padding: 16px 48px 16px 20px;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
  min-height: 44px;
  display: flex;
  align-items: center;
}

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

.faq-question::after {
  content: "+";
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  font-weight: 600;
  color: var(--color-primary-dark);
  transition: transform 0.2s ease;
}

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

.faq-question:hover {
  color: var(--color-primary-dark);
}

.faq-answer {
  padding: 0 20px 18px;
  border-top: 1px solid var(--color-border);
}

.faq-answer p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
}

/* ---- browse-path page: feedback ---- */

.feedback-body {
  padding: 22px 24px;
  background-color: var(--color-tint);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.feedback-body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
}

.feedback-body p:last-child {
  margin-bottom: 0;
}

/* ---- 404 ---- */

.site-error .site-main {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding-top: 48px;
  padding-bottom: 64px;
}

.error-panel {
  text-align: center;
  padding: 40px 24px;
  max-width: 560px;
  width: 100%;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.error-title {
  margin: 0 0 16px;
  font-size: 32px;
  font-weight: 700;
  color: var(--color-text);
}

.error-text {
  margin: 0 0 24px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-muted);
}

.error-home-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 24px;
  font-size: 15px;
  font-weight: 600;
  color: #FFFFFF;
  background-color: var(--color-primary);
  border-radius: var(--radius);
}

.error-home-link:hover {
  background-color: var(--color-primary-dark);
  color: #FFFFFF;
}

.error-routes {
  width: 100%;
  max-width: 720px;
  margin-top: 32px;
  text-align: center;
}

.error-routes-title {
  margin: 0 0 16px;
  font-size: 20px;
  font-weight: 600;
  color: var(--color-text);
}

.error-routes-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}

.error-route-item a {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: background-color 0.18s ease, border-color 0.18s ease, color 0.18s ease;
}

.error-route-item a:hover {
  background-color: var(--color-tint);
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
}

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

@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
  }

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

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

  .field-index {
    position: static;
  }
}

@media (max-width: 768px) {
  body {
    font-size: 15px;
  }

  .site-main {
    padding: 0 16px;
  }

  .header-inner {
    padding: 10px 16px;
    min-height: 60px;
  }

  .brand-logo {
    font-size: 18px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: block;
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    padding: 8px 16px 16px;
  }

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

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

  .nav-link {
    width: 100%;
    padding: 12px 14px;
    font-size: 16px;
    border-radius: var(--radius-sm);
  }

  .section {
    padding: 28px 0;
  }

  .section-title {
    font-size: 20px;
  }

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

  .page-description {
    font-size: 15px;
  }

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

  .hero-lead {
    font-size: 15px;
  }

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

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

  .collection-figure img,
  .field-figure img,
  .path-figure img {
    height: 200px;
  }

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

  .channel-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
    padding: 14px 16px;
  }

  .channel-row.channel-row-head {
    display: none;
  }

  .channel-cell-name::before {
    content: "频道：";
    color: var(--color-muted);
    font-weight: 400;
  }

  .channel-cell-theme::before {
    content: "题材取向：";
    color: var(--color-muted);
    font-weight: 400;
  }

  .channel-cell-use::before {
    content: "适用查阅：";
    color: var(--color-muted);
    font-weight: 400;
  }

  .channel-table {
    border: none;
    border-radius: 0;
    background-color: transparent;
  }

  .channel-table .channel-row {
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    margin-bottom: 10px;
    background-color: var(--color-surface);
  }

  .channel-table .channel-row:last-child {
    margin-bottom: 0;
  }

  .relation-row,
  .comparison-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
    padding: 14px 16px;
  }

  .relation-row-head,
  .comparison-head {
    display: none;
  }

  .relation-table,
  .comparison-table {
    border: none;
    border-radius: 0;
    background-color: transparent;
  }

  .relation-table .relation-row,
  .comparison-table .comparison-row {
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    margin-bottom: 10px;
    background-color: var(--color-surface);
  }

  .relation-table .relation-row:last-child,
  .comparison-table .comparison-row:last-child {
    margin-bottom: 0;
  }

  .field-table {
    display: block;
    border: none;
    border-radius: 0;
    background-color: transparent;
    font-size: 14px;
  }

  .field-table thead {
    display: none;
  }

  .field-table tbody,
  .field-table tr,
  .field-table th,
  .field-table td {
    display: block;
    width: 100%;
  }

  .field-table tbody tr {
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    margin-bottom: 10px;
    background-color: var(--color-surface);
    overflow: hidden;
  }

  .field-table tbody tr:last-child {
    margin-bottom: 0;
  }

  .field-table tbody th {
    padding: 12px 16px 8px;
    border-bottom: none;
    white-space: normal;
  }

  .field-table tbody td {
    padding: 6px 16px 12px;
    border-bottom: none;
  }

  .field-table tbody td:last-child {
    padding-bottom: 14px;
  }

  .field-table tbody tr:hover {
    background-color: var(--color-surface);
  }

  .step-item {
    grid-template-columns: 40px minmax(0, 1fr);
    gap: 12px;
    padding: 18px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 24px;
    padding: 32px 16px 24px;
  }

  .footer-brand {
    max-width: none;
  }

  .footer-nav {
    gap: 32px;
  }

  .footer-copy {
    padding: 14px 16px 20px;
  }

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

@media (max-width: 420px) {
  .hero-actions {
    flex-direction: column;
  }

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

  .need-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .footer-nav {
    flex-direction: column;
    gap: 20px;
  }

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