.page-about {
  --about-rail: 88px;
  --about-note: 236px;
  --about-gap: var(--space-3);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  margin: 0 0 var(--space-6);
  color: inherit;
  opacity: 0.75;
}
.page-about .about-crumbs a {
  color: inherit;
  text-decoration: none;
}
.page-about .about-crumbs a:hover {
  text-decoration: underline;
}

/* ---------- 开篇 ---------- */
.page-about .about-intro {
  color: var(--color-primary-ink);
}
.page-about .about-intro__grid {
  display: grid;
  gap: var(--space-6);
}
.page-about .about-eyebrow {
  color: inherit;
  opacity: 0.72;
  margin: 0 0 var(--space-2);
}
.page-about .about-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 0 var(--space-4);
  color: inherit;
  text-wrap: balance;
}
.page-about .about-lede {
  font-size: var(--text-lg);
  line-height: 1.45;
  margin: 0 0 var(--space-4);
  max-width: var(--measure);
  color: inherit;
}
.page-about .about-text {
  margin: 0 0 var(--space-3);
  max-width: var(--measure);
  color: inherit;
  opacity: 0.88;
}
.page-about .about-text a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.page-about .about-intro__media {
  margin: 0;
}
.page-about .about-intro__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg);
}

/* ---------- 章节头 ---------- */
.page-about .about-head {
  margin-bottom: var(--space-6);
}
.page-about .about-head .sec-head__lead {
  max-width: var(--measure);
}
.page-about .about-scale .about-head,
.page-about .about-head--onPrimary {
  color: var(--color-contrast-ink);
}
.page-about .about-head--onPrimary {
  color: var(--color-primary-ink);
}
.page-about .about-scale .sec-head__title,
.page-about .about-scale .sec-head__lead {
  color: var(--color-contrast-ink);
}
.page-about .about-scale .sec-head__idx {
  color: var(--color-contrast-accent);
}
.page-about .about-head--onPrimary .sec-head__title,
.page-about .about-head--onPrimary .sec-head__lead {
  color: var(--color-primary-ink);
}
.page-about .about-head--onPrimary .sec-head__idx {
  color: var(--color-primary-ink);
  opacity: 0.7;
}

/* ---------- 时间轴 ---------- */
.page-about .about-figure {
  margin: 0 0 var(--space-8);
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-8);
  position: relative;
}
.page-about .timeline::before {
  display: none;
}
.page-about .timeline__node {
  display: grid;
  gap: var(--space-3);
}
.page-about .timeline__no {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  line-height: 0.86;
  font-weight: var(--weight-heading);
  letter-spacing: -0.05em;
  font-variant-numeric: tabular-nums;
  color: var(--color-primary);
  margin: 0;
}
.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);
  color: var(--color-ink);
}
.page-about .timeline__body p {
  margin: 0 0 var(--space-3);
  max-width: var(--measure);
}
.page-about .timeline__body p:last-child {
  margin-bottom: 0;
}

.page-about .about-note {
  background: var(--color-surface-deep);
  padding: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.page-about .about-note > summary {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-2);
  cursor: pointer;
  list-style: none;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-ink);
}
.page-about .about-note > summary::-webkit-details-marker {
  display: none;
}
.page-about .about-note > summary::after {
  content: "＋";
  font-family: var(--font-mono);
  color: var(--color-primary);
  flex: none;
}
.page-about .about-note[open] > summary::after {
  content: "－";
}
.page-about .about-note[open] > summary {
  margin-bottom: var(--space-2);
}
.page-about .about-note p {
  margin: 0;
  line-height: 1.6;
}

/* ---------- 存量 ---------- */
.page-about .about-scale {
  color: var(--color-contrast-ink);
}
.page-about .scale-chart {
  list-style: none;
  margin: 0 0 var(--space-8);
  padding: 0;
  display: grid;
  gap: var(--space-3);
}
.page-about .scale-chart__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-1) var(--space-3);
}
.page-about .scale-chart__label {
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-contrast-ink);
  order: 1;
}
.page-about .scale-chart__value {
  order: 2;
  text-align: right;
  font-variant-numeric: tabular-nums;
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  color: var(--color-contrast-accent);
  white-space: nowrap;
}
.page-about .scale-chart__unit {
  font-size: var(--text-sm);
  margin-left: 4px;
  opacity: 0.72;
  font-weight: var(--weight-body);
}
.page-about .scale-chart__track {
  order: 3;
  grid-column: 1 / -1;
  display: block;
  height: 8px;
  background: var(--color-contrast-line);
  overflow: hidden;
}
.page-about .scale-chart__fill {
  display: block;
  height: 100%;
  width: var(--fill, 0%);
  min-width: 3px;
  background: var(--color-contrast-accent);
}

.page-about .scale-cats__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  letter-spacing: 0.06em;
  margin: 0 0 var(--space-4);
  color: var(--color-contrast-ink);
}
.page-about .lineup-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-4);
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}
.page-about .lineup-grid__item {
  display: grid;
  gap: var(--space-1);
  align-content: start;
}
.page-about .lineup-grid__num {
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
  color: var(--color-contrast-accent);
}
.page-about .lineup-grid__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  color: var(--color-contrast-ink);
}
.page-about .lineup-grid__desc {
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-contrast-ink);
  opacity: 0.75;
}

/* ---------- 分工 ---------- */
.page-about .team-grid {
  display: grid;
  gap: var(--space-6);
}
.page-about .team-grid__media {
  margin: 0;
}
.page-about .team-grid__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-lg);
}
.page-about .team-roster {
  margin: 0;
  display: grid;
  gap: var(--space-6);
}
.page-about .team-roster__row {
  display: grid;
  gap: var(--space-2);
}
.page-about .team-roster__role {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  letter-spacing: 0.04em;
  color: var(--color-primary);
  margin: 0;
}
.page-about .team-roster__desc {
  margin: 0;
  max-width: var(--measure);
  color: var(--color-ink-soft);
  line-height: var(--leading-body);
}
.page-about .team-cadence {
  margin-top: var(--space-8);
  padding-top: var(--space-6);
  background: var(--color-surface-deep);
  padding: var(--space-6) var(--space-4);
  display: grid;
  gap: var(--space-2);
}
.page-about .team-cadence__line {
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2);
  font-size: var(--text-base);
  color: var(--color-ink);
}
.page-about .team-cadence__key {
  min-width: 5.5em;
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-accent);
  font-weight: var(--weight-heading);
}

/* ---------- 边界 ---------- */
.page-about .about-limits {
  color: var(--color-primary-ink);
}
.page-about .limit-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-6);
}
.page-about .limit-list__item {
  display: grid;
  grid-template-columns: 2.5em minmax(0, 1fr);
  gap: var(--space-3);
  align-items: start;
}
.page-about .limit-list__no {
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: 0.08em;
  color: var(--color-primary-ink);
  opacity: 0.6;
  line-height: 1.5;
}
.page-about .limit-list__text {
  margin: 0;
  max-width: var(--measure);
  color: var(--color-primary-ink);
  line-height: var(--leading-body);
}
.page-about .limit-list__text a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 原则 ---------- */
.page-about .rule-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-8);
  counter-reset: rule;
}
.page-about .rule-list__item {
  display: grid;
  gap: var(--space-2);
}
.page-about .rule-list__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;
  color: var(--color-ink);
}
.page-about .rule-list__item p {
  margin: 0;
  max-width: var(--measure);
  color: var(--color-ink-soft);
  line-height: var(--leading-body);
}
.page-about .rule-list__item a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.page-about .rules-foot {
  margin-top: var(--space-8);
  background: var(--color-highlight);
  padding: var(--space-6) var(--space-4);
}
.page-about .rules-foot__line {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

/* ---------- 焦点态 ---------- */
.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-title {
    font-size: var(--text-2xl);
  }
  .page-about .scale-chart__row {
    grid-template-columns: 190px minmax(0, 1fr) 150px;
  }
  .page-about .scale-chart__label {
    order: 1;
  }
  .page-about .scale-chart__track {
    order: 2;
    grid-column: 2;
    height: 12px;
  }
  .page-about .scale-chart__value {
    order: 3;
    grid-column: 3;
  }
  .page-about .team-cadence {
    padding: var(--space-6) var(--space-8);
  }
}

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--space-8);
    align-items: start;
  }
  .page-about .about-intro__media {
    margin-top: var(--space-6);
  }
  .page-about .timeline::before {
    content: "";
    display: block;
    position: absolute;
    left: calc(var(--about-rail) / 2);
    top: 0;
    bottom: 0;
    width: var(--border-thin);
    background: color-mix(in srgb, var(--color-primary) 24%, transparent);
  }
  .page-about .timeline__node {
    grid-template-columns: var(--about-rail) minmax(0, 1fr) var(--about-note);
    gap: var(--about-gap);
    align-items: start;
  }
  .page-about .timeline__no {
    font-size: var(--text-3xl);
    padding-left: 4px;
  }
  .page-about .about-note {
    margin-top: 6px;
  }
  .page-about .team-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: var(--space-8);
    align-items: start;
  }
  .page-about .limit-list__item {
    grid-template-columns: 3.5em minmax(0, 1fr);
  }
  .page-about .rule-list {
    gap: var(--space-8);
  }
  .page-about .rule-list__item {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: var(--space-4);
    align-items: baseline;
  }
  .page-about .rule-list__title {
    font-size: var(--text-base);
  }
}

.page-about {
  --fill: currentColor;
}