.page-about {
  --about-gap: var(--space-6);
  display: block;
  background: var(--color-surface);
  color: var(--color-ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  position: relative;
  padding-block: var(--space-6) var(--space-8);
  background-color: var(--color-surface);
  background-image:
    radial-gradient(120% 100% at 92% 0%, color-mix(in srgb, var(--color-accent) 13%, transparent) 0%, transparent 58%),
    radial-gradient(110% 90% at 4% 8%, color-mix(in srgb, var(--color-primary) 15%, transparent) 0%, transparent 56%);
  overflow: clip;
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  margin: 0 0 var(--space-6);
  padding: 0;
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}

.page-about .breadcrumb li + li {
  margin-left: var(--space-2);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: var(--space-2);
  color: var(--color-line);
}

.page-about .breadcrumb a {
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: var(--border-thin) solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--color-primary);
  border-bottom-color: color-mix(in srgb, var(--color-primary) 45%, transparent);
}

.page-about .about-intro-body {
  display: grid;
  gap: var(--space-3);
}

.page-about .section-kicker {
  margin: 0;
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}

.page-about .about-title {
  margin: 0;
  max-width: 20ch;
  font-family: var(--font-heading);
  font-size: var(--text-4xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-about .about-lede {
  margin: 0;
  max-width: 62ch;
  font-size: var(--text-lg);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-badges {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin: var(--space-2) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-badges li {
  padding: var(--space-1) var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  background: color-mix(in srgb, var(--color-surface) 76%, transparent);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

@media (min-width: 900px) {
  .page-about .about-intro-body {
    grid-template-columns: repeat(12, 1fr);
    column-gap: var(--gutter);
    row-gap: var(--space-2);
    align-items: start;
  }
  .page-about .about-intro-body .section-kicker { grid-column: 1 / -1; }
  .page-about .about-title { grid-column: 1 / span 7; }
  .page-about .about-lede { grid-column: 8 / span 5; }
  .page-about .about-badges { grid-column: 1 / -1; }
}

/* ---------- 叙事章节 ---------- */
.page-about .about-chapter {
  padding-block: var(--section-y);
}

.page-about .chapter-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  align-items: start;
}

.page-about .chapter-text .prose p {
  margin: 0 0 var(--space-3);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-about .chapter-text .prose p:last-child {
  margin-bottom: 0;
}

.page-about .section-title {
  margin: var(--space-2) 0 var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-about .section-lede {
  margin: 0;
  max-width: 68ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .inline-link {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 38%, transparent);
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  color: var(--color-focus);
  border-bottom-color: var(--color-focus);
}

.page-about .chapter-points {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-about .chapter-points li {
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1fr);
  gap: var(--space-2);
  padding-block: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

.page-about .point-key {
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}

.page-about .chapter-figure {
  margin: 0;
}

.page-about .chapter-figure .media {
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid var(--color-line);
  background: var(--color-surface-alt);
}

.page-about .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media-caption {
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  line-height: 1.7;
  color: var(--color-ink-muted);
}

@media (min-width: 900px) {
  .page-about .chapter-grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: var(--gutter);
  }
  .page-about .chapter-text { grid-column: 1 / span 6; }
  .page-about .chapter-figure { grid-column: 8 / span 5; }
  .page-about .about-chapter--flip .chapter-text { grid-column: 7 / span 6; }
  .page-about .about-chapter--flip .chapter-figure { grid-column: 1 / span 5; }
}

/* ---------- 时间脉络 ---------- */
.page-about .about-timeline-band {
  padding-block: var(--section-y);
  background: var(--color-surface-alt);
}

.page-about .about-bed {
  position: relative;
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  background-color: var(--color-primary);
  background-image:
    radial-gradient(110% 130% at 88% 6%, color-mix(in srgb, var(--color-accent) 90%, transparent) 0%, transparent 60%),
    radial-gradient(120% 140% at 6% 98%, color-mix(in srgb, var(--color-contrast-surface) 82%, transparent) 0%, transparent 64%);
  overflow: clip;
}

.page-about .about-trail-panel {
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--color-surface) 88%, transparent);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-highlight) 88%, transparent);
  box-shadow: var(--shadow-2);
  backdrop-filter: blur(16px) saturate(1.08);
  -webkit-backdrop-filter: blur(16px) saturate(1.08);
}

.page-about .about-trail-panel .section-kicker {
  color: var(--color-accent);
}

.page-about .about-trail-panel .section-title {
  margin-bottom: 0;
}

@media (min-width: 768px) {
  .page-about .about-bed { padding: var(--space-4); }
  .page-about .about-trail-panel { padding: var(--space-6); }
}

.page-about .about-trail {
  position: relative;
  list-style: none;
  margin: var(--space-6) 0 0;
  padding: 0;
}

.page-about .about-trail::before {
  content: "";
  position: absolute;
  left: calc(var(--space-1) - var(--border-thin));
  top: var(--space-3);
  bottom: var(--space-3);
  width: var(--border-thin);
  background: color-mix(in srgb, var(--color-primary) 32%, transparent);
}

.page-about .about-trail .timeline-item {
  position: relative;
  padding-left: var(--space-6);
  padding-bottom: var(--space-4);
}

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

.page-about .about-trail .timeline-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: calc(var(--space-1) * 0.5);
  width: var(--space-2);
  height: var(--space-2);
  box-sizing: border-box;
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 60%, transparent);
}

.page-about .about-trail .timeline-item.is-current::before {
  background: var(--color-accent);
  border-color: var(--color-accent);
  box-shadow: 0 0 0 calc(var(--space-1) * 0.5) color-mix(in srgb, var(--color-accent) 20%, transparent);
}

.page-about .trail-stage {
  margin: 0 0 var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-primary);
}

.page-about .trail-title {
  margin: 0 0 var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .trail-desc {
  margin: 0 0 var(--space-2);
  max-width: 64ch;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .trail-link {
  display: inline-block;
  padding-bottom: 2px;
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 40%, transparent);
  opacity: 0.78;
  transition: opacity 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-trail .timeline-item:hover .trail-link,
.page-about .about-trail .timeline-item:focus-within .trail-link {
  opacity: 1;
}

.page-about .trail-link:hover,
.page-about .trail-link:focus-visible {
  color: var(--color-focus);
  border-bottom-color: var(--color-focus);
}

/* ---------- 编辑分工 ---------- */
.page-about .about-editorial .section-head {
  max-width: 78ch;
}

.page-about .desk-list {
  display: grid;
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.page-about .desk-item {
  position: relative;
  padding: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
  border-top: calc(var(--border-thin) * 3) solid var(--color-primary);
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  transition: box-shadow 0.18s ease, border-color 0.18s ease;
}

.page-about .desk-item:nth-child(2) { border-top-color: var(--color-accent); }
.page-about .desk-item:nth-child(3) { border-top-color: var(--color-contrast-accent); }

.page-about .desk-item:hover,
.page-about .desk-item:focus-within {
  box-shadow: var(--shadow-1);
  border-color: color-mix(in srgb, var(--color-primary) 26%, var(--color-line));
}

.page-about .desk-index {
  margin: 0 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}

.page-about .desk-title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .desk-text {
  margin: 0 0 var(--space-3);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .desk-meta {
  margin: 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

@media (min-width: 900px) {
  .page-about .desk-list {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: var(--space-4) var(--gutter);
  }
  .page-about .desk-item:nth-child(1) { grid-column: 1 / span 7; }
  .page-about .desk-item:nth-child(2) { grid-column: 5 / span 8; }
  .page-about .desk-item:nth-child(3) { grid-column: 2 / span 7; }
}

.page-about .boundary-note {
  margin-top: var(--space-6);
  padding: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--color-surface-deep) 62%, transparent);
}

.page-about .boundary-title {
  margin: 0 0 var(--space-2);
  font-size: var(--text-sm);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
  font-weight: var(--weight-body);
}

.page-about .boundary-list {
  display: grid;
  gap: var(--space-1);
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .boundary-list li {
  position: relative;
  padding-left: var(--space-3);
  font-size: var(--text-sm);
  line-height: 1.75;
  color: var(--color-ink-soft);
}

.page-about .boundary-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: calc(var(--space-1) * 0.75);
  height: calc(var(--space-1) * 0.75);
  border-radius: var(--radius-pill);
  background: color-mix(in srgb, var(--color-primary) 62%, transparent);
}

/* ---------- 口径分歧 ---------- */
.page-about .dispute-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-6);
}

.page-about .rule-steps {
  display: grid;
  gap: var(--space-3);
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .rule-step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  column-gap: var(--space-2);
  row-gap: var(--space-1);
  padding-bottom: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-about .rule-step:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .rule-num {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  font-variant-numeric: tabular-nums;
}

.page-about .rule-title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  line-height: 1.5;
  color: var(--color-ink);
}

.page-about .rule-text {
  grid-column: 2;
  margin: 0;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

@media (min-width: 900px) {
  .page-about .dispute-grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: var(--gutter);
    align-items: start;
  }
  .page-about .dispute-head {
    grid-column: 1 / span 5;
    position: sticky;
    top: var(--space-6);
  }
  .page-about .rule-steps {
    grid-column: 7 / span 6;
  }
}

/* ---------- 覆盖规模 ---------- */
.page-about .about-scale {
  padding-block: var(--section-y);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-about .about-scale .section-kicker {
  color: var(--color-contrast-accent);
}

.page-about .about-scale .section-title {
  color: var(--color-contrast-ink);
}

.page-about .scale-head {
  max-width: 70ch;
}

.page-about .scale-lede {
  margin: var(--space-2) 0 0;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent);
}

.page-about .scale-list {
  display: grid;
  list-style: none;
  margin: var(--space-6) 0 0;
  padding: 0;
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-about .scale-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: baseline;
  column-gap: var(--space-4);
  row-gap: var(--space-1);
  padding-block: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
  transition: background-color 0.18s ease;
}

.page-about .scale-item:hover,
.page-about .scale-item:focus-within {
  background: color-mix(in srgb, var(--color-contrast-ink) 6%, transparent);
}

.page-about .scale-term {
  margin: 0;
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent);
}

.page-about .scale-value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  line-height: 1.1;
  color: var(--color-contrast-accent);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.page-about .scale-num {
  font-size: inherit;
  font-variant-numeric: tabular-nums;
}

.page-about .scale-unit {
  margin-left: var(--space-1);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

.page-about .scale-hint {
  grid-column: 1 / -1;
  margin: 0;
  font-size: var(--text-xs);
  line-height: 1.7;
  color: color-mix(in srgb, var(--color-contrast-ink) 64%, transparent);
}

.page-about .scale-figure {
  margin: var(--space-6) 0 0;
}

.page-about .scale-figure .media {
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid var(--color-contrast-line);
}

.page-about .scale-figure .media-caption {
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

@media (min-width: 1024px) {
  .page-about .scale-value {
    font-size: var(--text-3xl);
  }
}

/* ---------- 收束 ---------- */
.page-about .about-outro {
  padding-block: var(--section-y);
  background: var(--color-surface);
}

.page-about .about-rule {
  height: var(--border-thin);
  margin: 0 0 var(--space-6);
  border: 0;
  background: var(--color-line);
}

.page-about .outro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
  align-items: start;
}

.page-about .outro-title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .outro-text p {
  margin: 0;
  max-width: 64ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .outro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

@media (min-width: 900px) {
  .page-about .outro-grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: var(--gutter);
    align-items: end;
  }
  .page-about .outro-text { grid-column: 1 / span 7; }
  .page-about .outro-actions { grid-column: 9 / span 4; justify-content: flex-end; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}