.page-about {
  --stage-pad: clamp(20px, 3vw, 36px);
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-body);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding: clamp(14px, 2.4vw, 24px) 0 0;
}
.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.page-about .breadcrumb__list li + li::before {
  content: "/";
  margin: 0 10px;
  color: var(--line);
}
.page-about .breadcrumb__list a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.page-about .breadcrumb__list a:hover {
  color: var(--bamboo);
  border-bottom-color: var(--bamboo);
}
.page-about .breadcrumb__list [aria-current="page"] {
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-lead {
  padding: clamp(28px, 4vw, 54px) 0 clamp(40px, 5vw, 74px);
}
.page-about .about-lead__grid {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
}
.page-about .about-lead__main h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(29px, 6.4vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--ink);
}
.page-about .about-lead__main .lead {
  margin: 22px 0 0;
  max-width: 60ch;
  font-size: clamp(16px, 1.6vw, 18.5px);
  line-height: 1.8;
  color: var(--text);
}

.page-about .facts {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}
.page-about .fact {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .fact__num {
  flex: none;
  min-width: 4.6em;
  font-size: clamp(19px, 2.8vw, 26px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--copper);
}
.page-about .fact__label {
  font-size: 14.5px;
  line-height: 1.62;
  color: var(--muted);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding: clamp(46px, 6vw, 86px) 0;
  border-top: 1px solid var(--line);
}
.page-about .section-head {
  margin-bottom: clamp(24px, 3.4vw, 44px);
}
.page-about .section-head__desc {
  max-width: 62ch;
}

/* ---------- 图 ---------- */
.page-about .about-figure {
  margin: clamp(24px, 3.4vw, 40px) 0 0;
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  background: var(--paper-2);
}
.page-about .about-figure--wide img {
  aspect-ratio: 16 / 6;
}
.page-about .about-figure--tall img {
  aspect-ratio: 4 / 3;
}
.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--muted);
}

/* ---------- 01 主张 ---------- */
.page-about .claim__text {
  max-width: 68ch;
}
.page-about .claim__text p {
  margin: 0;
  font-size: 17px;
  line-height: 1.85;
}
.page-about .claim__text p + p {
  margin-top: 16px;
}

/* ---------- 02 沿革 ---------- */
.page-about .timeline__grid {
  display: grid;
  gap: clamp(28px, 3.6vw, 44px);
}
.page-about .stages {
  border-left: 4px solid var(--copper);
  margin-left: 5px;
  padding-left: var(--stage-pad);
}
.page-about .stage {
  position: relative;
}
.page-about .stage + .stage {
  margin-top: 6px;
}
.page-about .stage::before {
  content: "";
  position: absolute;
  top: 26px;
  left: calc(-1 * var(--stage-pad) - 9px);
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--copper);
  box-shadow: 0 0 0 4px var(--paper);
}
.page-about .stage--now::before {
  background: var(--paper);
  border: 2px solid var(--copper);
}
.page-about .stage__head {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
}
.page-about .stage__trigger {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 14px;
  width: 100%;
  padding: 20px 0 14px;
  background: none;
  border: 0;
  border-bottom: 1px dashed var(--line);
  text-align: left;
  color: inherit;
  font: inherit;
  cursor: pointer;
}
.page-about .stage__trigger:focus-visible {
  outline: 2px solid var(--bamboo-bright);
  outline-offset: 3px;
}
.page-about .stage__year {
  flex: none;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--copper);
}
.page-about .stage__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.3;
  color: var(--ink);
  transition: color var(--dur) var(--ease);
}
.page-about .stage__trigger:hover .stage__name {
  color: var(--bamboo);
}
.page-about .stage__trigger .accordion__mark {
  margin-left: auto;
}
.page-about .stage__panel {
  padding: 16px 0 26px;
}
.page-about .stage__meta {
  margin: 0;
  display: grid;
  gap: 6px 18px;
}
.page-about .stage__meta dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--copper);
}
.page-about .stage__meta dd {
  margin: 0 0 12px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--text);
}
.page-about .timeline__aside .about-figure {
  margin-top: 0;
}
.page-about .timeline__note {
  margin: 18px 0 0;
  color: var(--muted);
}

/* ---------- 03 审校 ---------- */
.page-about .review__grid {
  display: grid;
  gap: clamp(28px, 3.6vw, 44px);
}
.page-about .review__flow {
  display: grid;
  gap: 12px;
}
.page-about .flow__item {
  background: var(--paper-2);
  border-radius: var(--radius);
  border-left: 3px solid transparent;
  transition: border-color var(--dur) var(--ease);
}
.page-about .flow__item:hover,
.page-about .flow__item:focus-within {
  border-left-color: var(--bamboo);
}
.page-about .flow__trigger {
  display: flex;
  align-items: baseline;
  gap: 10px;
  width: 100%;
  padding: 15px 16px;
  background: none;
  border: 0;
  text-align: left;
  color: var(--ink);
  font: inherit;
  cursor: pointer;
}
.page-about .flow__trigger:focus-visible {
  outline: 2px solid var(--bamboo-bright);
  outline-offset: -2px;
}
.page-about .flow__num {
  flex: none;
  font-size: 13px;
  color: var(--copper);
}
.page-about .flow__name {
  font-weight: 600;
  font-size: 15.5px;
  line-height: 1.5;
}
.page-about .flow__trigger .accordion__mark {
  margin-left: auto;
}
.page-about .flow__panel {
  padding: 0 16px 16px 16px;
}
.page-about .flow__panel p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .review__card {
  background: var(--ink-2);
  color: var(--on-ink);
  padding: clamp(22px, 3vw, 32px);
}
.page-about .review__card-label {
  margin: 0 0 18px;
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--bamboo-bright);
}
.page-about .review__duties {
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .review__duties li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px solid var(--ink-line);
  font-size: 15.5px;
  line-height: 1.6;
}
.page-about .review__duties li:last-child {
  border-bottom: 0;
}
.page-about .review__duties .t-mono {
  flex: none;
  width: 1.4em;
  color: var(--copper);
  font-size: 12.5px;
}
.page-about .review__card-note {
  margin: 16px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--on-ink-soft);
}
.page-about .review__side .about-figure {
  margin-top: 22px;
}

/* ---------- 04 伙伴 ---------- */
.page-about .partners__grid {
  display: grid;
  gap: clamp(28px, 3.6vw, 44px);
}
.page-about .roles {
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}
.page-about .role {
  display: flex;
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .role__k {
  flex: none;
  min-width: 3.4em;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--copper);
  padding-top: 3px;
}
.page-about .role p {
  margin: 0;
  font-size: 16px;
  line-height: 1.78;
}
.page-about .partners__text {
  margin: 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}
.page-about .cluster-map {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--paper-2);
  border-radius: var(--radius);
}
.page-about .cluster-map .cluster-row {
  outline: none;
}
.page-about .cluster-map .cluster-row circle {
  fill: var(--bamboo);
  fill-opacity: 0.32;
  transition: fill var(--dur) var(--ease), fill-opacity var(--dur) var(--ease);
}
.page-about .cluster-map .cluster-row:hover circle,
.page-about .cluster-map .cluster-row:focus circle {
  fill: var(--bamboo-bright);
  fill-opacity: 1;
}
.page-about .cluster-map .cluster-row text {
  opacity: 0;
  fill: var(--ink);
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.02em;
  transition: opacity var(--dur) var(--ease);
}
.page-about .cluster-map .cluster-row:hover text,
.page-about .cluster-map .cluster-row:focus text {
  opacity: 1;
}
.page-about .cluster-map__note {
  margin: 12px 0 0;
  color: var(--muted);
}

/* ---------- 05 凭据 ---------- */
.page-about .credits {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0 clamp(24px, 3.4vw, 44px);
  border-top: 1px solid var(--line);
}
.page-about .credit {
  display: flex;
  gap: 18px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .credit__badge {
  flex: none;
  width: 20px;
  height: 20px;
  margin-top: 6px;
  border: 1.5px solid var(--gold);
  transform: rotate(45deg);
}
.page-about .credit__body h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.page-about .credit__body p {
  margin: 0;
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 结尾 ---------- */
.page-about .about-next {
  background: var(--ink);
  color: var(--on-ink);
  padding: clamp(44px, 5.5vw, 76px) 0;
}
.page-about .about-next__grid {
  display: grid;
  gap: clamp(24px, 3.4vw, 42px);
}
.page-about .about-next__main h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(22px, 3.2vw, 32px);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--on-ink);
}
.page-about .about-next__main p {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--on-ink-soft);
}
.page-about .about-next .link-line {
  color: var(--bamboo-bright);
  text-decoration: none;
  border-bottom: 1px solid var(--bamboo-bright);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.page-about .about-next .link-line:hover {
  color: var(--copper);
  border-bottom-color: var(--copper);
}
.page-about .about-next__line {
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: var(--on-ink-faint);
}
.page-about .about-next__aside .btn {
  text-decoration: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .stage__meta {
    grid-template-columns: 96px 1fr;
  }
  .page-about .review__flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .credits {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-lead__grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
  .page-about .timeline__grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
  .page-about .review__grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
  .page-about .review__card {
    position: sticky;
    top: calc(var(--header-h-compact) + 24px);
  }
  .page-about .partners__grid {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }
  .page-about .about-next__grid {
    grid-template-columns: 8fr 4fr;
    align-items: end;
  }
  .page-about .about-next__aside {
    text-align: right;
  }
}

@media (min-width: 1080px) {
  .page-about .review__flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage__name,
  .page-about .flow__item,
  .page-about .cluster-map .cluster-row circle,
  .page-about .cluster-map .cluster-row text,
  .page-about .link-line {
    transition: none;
  }
}
</main>