.page-about {
  background: var(--color-surface);
  color: var(--color-ink);
  overflow-x: clip;
}

/* 面包屑行 */
.page-about .about-masthead {
  padding-top: var(--space-6);
  padding-bottom: 0;
}

/* ── 开场 ── */
.page-about .about-opening {
  padding-top: var(--space-4);
}

.page-about .about-opening__grid {
  display: grid;
  gap: var(--space-6);
}

.page-about .about-opening__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  margin: var(--space-3) 0 var(--space-4);
  max-width: 20ch;
}

.page-about .about-opening__body {
  margin: 0 auto 0 0;
  max-width: var(--measure);
  color: var(--color-ink-soft);
  font-size: var(--text-base);
  line-height: var(--leading-body);
}

.page-about .about-opening__body + .about-opening__body {
  margin-top: var(--space-3);
}

.page-about .about-opening__figures {
  display: grid;
  gap: var(--space-2);
  align-content: start;
}

.page-about .figures-block {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-pill);
}

.page-about .figures-block__value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-lg);
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}

.page-about .figures-block__label {
  font-size: var(--text-sm);
  line-height: 1.3;
}

.page-about .figures-block--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

.page-about .figures-block--primary .figures-block__label {
  opacity: 0.82;
}

.page-about .figures-block--accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}

.page-about .figures-block--accent .figures-block__label {
  opacity: 0.82;
}

.page-about .figures-block--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-about .figures-block--deep .figures-block__value {
  color: var(--color-contrast-accent);
}

.page-about .figures-block--deep .figures-block__label {
  opacity: 0.82;
}

/* ── 品牌与站点 ── */
.page-about .about-brand {
  padding-top: var(--space-8);
}

.page-about .about-brand__frame {
  position: relative;
  margin: 0;
  display: block;
  aspect-ratio: 1 / 1;
  overflow: hidden;
  isolation: isolate;
}

.page-about .about-brand__frame .media-frame__img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-brand__frame .media-frame__body {
  position: absolute;
  inset: 0;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: var(--space-2);
  padding: var(--space-5, var(--space-4));
  background: var(--overlay-scrim);
  color: var(--color-contrast-ink);
}

.page-about .about-brand__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  margin: 0;
}

.page-about .about-brand__copy {
  margin: 0;
  max-width: 52ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
  opacity: 0.9;
}

.page-about .about-brand__detail {
  margin-top: var(--space-6);
}

.page-about .about-brand__detail a {
  color: var(--color-primary);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.page-about .about-brand__detail a:hover,
.page-about .about-brand__detail a:focus-visible {
  color: var(--color-accent);
}

/* ── 发展脉络 ── */
.page-about .about-timeline {
  padding-top: var(--space-8);
}

.page-about .about-timeline__head {
  margin-bottom: var(--space-6);
}

.page-about .about-timeline__head .lede {
  margin-top: var(--space-3);
  max-width: var(--measure);
  color: var(--color-ink-soft);
}

.page-about .about-timeline__layout {
  display: grid;
  gap: var(--space-6);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 var(--space-6) var(--space-5, var(--space-4));
  border-left: var(--border-thin) solid var(--color-line);
}

.page-about .timeline__item:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.page-about .timeline__node {
  position: absolute;
  left: -13px;
  top: 2px;
  width: 24px;
  height: 24px;
  display: block;
}

.page-about .timeline__item:nth-child(odd) .timeline__node {
  border-radius: 50%;
  background: var(--color-primary);
}

.page-about .timeline__item:nth-child(even) .timeline__node {
  border-radius: 0;
  background: var(--color-accent);
}

.page-about .timeline__era {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--color-ink-muted);
  margin: 0 0 var(--space-1);
}

.page-about .timeline__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  margin: 0 0 var(--space-2);
}

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

.page-about .timeline__desc a {
  color: var(--color-accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.page-about .timeline__desc a:hover,
.page-about .timeline__desc a:focus-visible {
  color: var(--color-primary);
}

.page-about .about-timeline__aside {
  margin: 0;
}

.page-about .about-timeline__aside .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 8 / 9;
  object-fit: cover;
}

.page-about .about-timeline__aside .media-frame__body {
  padding: var(--space-3) 0 0;
  font-size: var(--text-sm);
  line-height: 1.5;
  color: var(--color-ink-muted);
}

/* ── 团队 ── */
.page-about .about-team {
  padding-top: var(--space-8);
}

.page-about .about-team__head {
  margin-bottom: var(--space-6);
}

.page-about .team-roster {
  display: grid;
  gap: 0;
}

.page-about .team-role {
  display: grid;
  gap: var(--space-2);
  padding: var(--space-4) 0;
  align-items: baseline;
}

.page-about .team-role__count {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-2xl);
  line-height: 1;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
}

.page-about .team-role:nth-child(1) .team-role__count {
  color: var(--color-primary);
}

.page-about .team-role:nth-child(2) .team-role__count {
  color: var(--color-accent);
}

.page-about .team-role:nth-child(3) .team-role__count {
  color: var(--color-contrast-surface);
}

.page-about .team-role__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  margin: 0 0 var(--space-2);
}

.page-about .team-role__desc {
  margin: 0;
  max-width: 52ch;
  color: var(--color-ink-soft);
  font-size: var(--text-base);
  line-height: var(--leading-body);
}

.page-about .about-team__note {
  margin: var(--space-6) auto 0 0;
  max-width: var(--measure);
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-line);
  color: var(--color-ink-soft);
  font-size: var(--text-base);
  line-height: var(--leading-body);
}

/* ── 内容边界 ── */
.page-about .about-boundary {
  padding-top: var(--space-8);
}

.page-about .about-boundary__panel {
  position: relative;
  background: var(--color-accent);
  color: var(--color-accent-ink);
  padding: var(--space-6) var(--space-4);
  overflow: hidden;
  isolation: isolate;
}

.page-about .about-boundary__panel::after {
  content: "";
  position: absolute;
  right: -90px;
  bottom: -110px;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--color-accent-ink) 14%, transparent);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-boundary__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-boundary__intro {
  margin: var(--space-3) 0 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  opacity: 0.9;
}

.page-about .about-boundary__grid {
  display: grid;
  gap: 0;
  margin-top: var(--space-4);
}

.page-about .boundary-card {
  padding: var(--space-3) 0;
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-accent-ink) 30%, transparent);
}

.page-about .boundary-card:last-child {
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-accent-ink) 30%, transparent);
}

.page-about .boundary-card summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}

.page-about .boundary-card summary::-webkit-details-marker {
  display: none;
}

.page-about .boundary-card summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-lg);
  line-height: 1;
}

.page-about .boundary-card[open] summary::after {
  content: "\2212";
}

.page-about .boundary-card summary:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 4px;
}

.page-about .boundary-card__index {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-sm);
  opacity: 0.78;
}

.page-about .boundary-card__desc {
  margin: var(--space-2) 0 0;
  max-width: 62ch;
  padding-inline-start: 2.8em;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  opacity: 0.92;
}

/* ── 运营原则 ── */
.page-about .about-principles {
  padding-top: var(--space-8);
}

.page-about .about-principles__head .lede {
  margin-top: var(--space-3);
  max-width: var(--measure);
  color: var(--color-ink-soft);
}

.page-about .principle-list {
  list-style: none;
  margin: var(--space-6) 0 0;
  padding: 0;
  display: grid;
  gap: var(--space-6);
}

.page-about .principle {
  display: grid;
  gap: var(--space-2);
}

.page-about .principle__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-lg);
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--color-accent);
}

.page-about .principle__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  margin: 0 0 var(--space-2);
}

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

.page-about .about-principles__banner {
  margin: var(--space-8) 0 0;
}

.page-about .about-principles__banner .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 3;
  object-fit: cover;
}

/* ── 收束入口 ── */
.page-about .about-handoff {
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
}

.page-about .about-handoff__grid {
  display: grid;
  gap: var(--space-6);
}

.page-about .about-handoff__lead .prose {
  margin-top: var(--space-3);
  color: var(--color-ink-soft);
}

.page-about .about-handoff__list {
  display: grid;
  gap: 0;
}

.page-about .handoff-link {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) 0;
  text-decoration: none;
  color: inherit;
  border-top: var(--border-thin) solid var(--color-line);
  transition: color 140ms ease, padding-inline-start 140ms ease;
}

.page-about .handoff-link:last-child {
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-about .handoff-link:hover,
.page-about .handoff-link:focus-visible {
  color: var(--color-primary);
  padding-inline-start: var(--space-2);
}

.page-about .handoff-link:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 4px;
}

.page-about .handoff-link__label {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}

.page-about .handoff-link__meta {
  font-size: var(--text-sm);
  line-height: 1.45;
  color: var(--color-ink-muted);
}

/* ── 响应式 ── */
@media (min-width: 640px) {
  .page-about .figures-block__value {
    font-size: var(--text-xl);
  }

  .page-about .about-boundary__panel {
    padding: var(--space-8) var(--space-6);
  }

  .page-about .timeline__item {
    padding-left: var(--space-6);
  }
}

@media (min-width: 760px) {
  .page-about .about-brand__frame {
    aspect-ratio: 2 / 1;
  }

  .page-about .about-brand__frame .media-frame__body {
    padding: var(--space-8);
  }

  .page-about .about-brand__title {
    font-size: var(--text-2xl);
  }

  .page-about .team-role {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: var(--space-6);
  }

  .page-about .team-role:nth-child(2) {
    margin-inline-start: var(--space-8);
  }

  .page-about .team-role:nth-child(3) {
    margin-inline-start: var(--space-4);
  }

  .page-about .principle {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: var(--space-4);
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .about-opening__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-about .about-opening__title {
    font-size: var(--text-2xl);
  }

  .page-about .figures-block {
    padding: var(--space-4) var(--space-6);
  }

  .page-about .figures-block:nth-child(2) {
    margin-inline-start: var(--space-6);
  }

  .page-about .figures-block:nth-child(3) {
    margin-inline-start: var(--space-3);
  }

  .page-about .about-brand__detail {
    max-width: 78ch;
  }
}

@media (min-width: 1000px) {
  .page-about .about-timeline__layout {
    grid-template-columns: minmax(0, 1.62fr) minmax(0, 1fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-about .about-timeline__aside {
    position: sticky;
    top: 96px;
  }

  .page-about .about-handoff__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: var(--space-8);
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .handoff-link {
    transition: none;
  }
}
</body>
</html>

.page-about {
  --space-5: var(--space-8);
}