.page-about {
  --about-rail-w: 208px;
  --about-glow: radial-gradient(60% 55% at 78% 10%, rgba(255, 106, 43, .2), transparent 70%);
  display: block;
  position: relative;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1rem, 3vw, 2rem) 0 clamp(2.25rem, 5vw, 3.5rem);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -25% -10% 0;
  background:
    var(--about-glow),
    radial-gradient(50% 45% at 10% 0%, rgba(33, 230, 210, .14), transparent 72%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(29, 78, 122, .18) 1px, transparent 1px),
    linear-gradient(90deg, rgba(29, 78, 122, .18) 1px, transparent 1px);
  background-size: 96px 96px;
  -webkit-mask-image: radial-gradient(70% 60% at 60% 18%, #000 15%, transparent 82%);
  mask-image: radial-gradient(70% 60% at 60% 18%, #000 15%, transparent 82%);
  pointer-events: none;
  z-index: 0;
}

.page-about .hero-slash {
  position: absolute;
  top: -12%;
  right: -14%;
  width: min(640px, 80vw);
  height: 480px;
  background: linear-gradient(152deg, rgba(255, 106, 43, .24), rgba(33, 230, 210, .12) 58%, transparent 88%);
  -webkit-clip-path: polygon(20% 0, 100% 0, 78% 100%, 0 100%);
  clip-path: polygon(20% 0, 100% 0, 78% 100%, 0 100%);
  transform: rotate(-6deg);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: center;
}

.page-about h1 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.9rem, 5.4vw, 3.35rem);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--serif-ink);
  margin: .6rem 0 0;
  max-width: 19ch;
}

.page-about .hero-copy .eyebrow {
  margin: 0;
}

.page-about .lede {
  margin: 1rem 0 0;
  max-width: 46ch;
  font-size: clamp(1rem, 1.7vw, 1.15rem);
  line-height: 1.8;
  color: var(--ink);
  opacity: .86;
}

.page-about .hero-facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(92px, 1fr));
  gap: 1rem;
  margin-top: clamp(1.5rem, 3vw, 2.25rem);
  padding-top: 1.25rem;
  border-top: 1px solid var(--line-soft);
}

.page-about .fact-num {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.5rem, 3.4vw, 2.35rem);
  line-height: 1;
  color: var(--orange);
}

.page-about .fact-unit {
  font-size: .55em;
  margin-left: .12em;
}

.page-about .fact-label {
  display: block;
  margin-top: .45rem;
  font-size: .8125rem;
  line-height: 1.5;
  color: var(--muted);
}

.page-about .about-media {
  margin: 0;
  border-radius: var(--radius-l);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--panel-deep);
  box-shadow: 0 26px 64px rgba(3, 12, 24, .55);
}

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

.page-about .hero-media {
  position: relative;
}

.page-about .hero-media::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 46%;
  background: linear-gradient(180deg, transparent, rgba(6, 26, 50, .72));
  pointer-events: none;
}

@media (min-width: 900px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: clamp(2rem, 4vw, 4rem);
  }
}

/* ---------- 长卷轴骨架 ---------- */
.page-about .about-body {
  padding: clamp(1rem, 3vw, 2rem) 0 clamp(3rem, 7vw, 5.5rem);
}

.page-about .about-layout {
  display: grid;
  gap: clamp(1.5rem, 4vw, 3rem);
}

.page-about .chapter-column {
  min-width: 0;
}

/* ---------- 章节轨道 ---------- */
.page-about .chapter-rail-title {
  margin: 0 0 .75rem;
  font-size: .75rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .chapter-list {
  list-style: none;
  margin: 0;
  padding: 0 0 .5rem;
  display: flex;
  gap: .5rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.page-about .chapter-list::-webkit-scrollbar {
  display: none;
}

.page-about .chapter-item {
  flex: 0 0 auto;
}

.page-about .chapter-link {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .5rem .85rem;
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  color: var(--muted);
  font-size: .875rem;
  line-height: 1.2;
  white-space: nowrap;
  text-decoration: none;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}

.page-about .chapter-link:hover,
.page-about .chapter-link:focus-visible {
  color: var(--ink);
  border-color: var(--cyan);
  background: rgba(33, 230, 210, .08);
}

.page-about .chapter-index {
  font-family: var(--mono);
  font-weight: 700;
  font-size: .75rem;
  color: var(--orange);
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 4rem);
  }

  .page-about .chapter-rail {
    position: -webkit-sticky;
    position: sticky;
    top: calc(var(--topbar-h) + 1.75rem);
    align-self: start;
  }

  .page-about .chapter-list {
    flex-direction: column;
    overflow: visible;
    gap: .2rem;
    padding-bottom: 0;
  }

  .page-about .chapter-link {
    display: flex;
    padding: .5rem .7rem;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0 var(--radius-s) var(--radius-s) 0;
    background: transparent;
  }

  .page-about .chapter-link:hover,
  .page-about .chapter-link:focus-visible {
    border-left-color: var(--orange);
    background: rgba(13, 39, 69, .75);
  }
}

/* ---------- 章节内容 ---------- */
.page-about .chapter {
  padding: clamp(2.25rem, 5vw, 3.75rem) 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: calc(var(--topbar-h) + 1.5rem);
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .chapter-num {
  display: block;
  font-family: var(--serif);
  font-weight: 600;
  font-style: normal;
  font-size: clamp(2.35rem, 7vw, 4.25rem);
  line-height: .9;
  letter-spacing: .02em;
  color: var(--orange);
  opacity: .88;
}

.page-about .chapter-title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.45rem, 3.2vw, 2.15rem);
  line-height: 1.3;
  color: var(--serif-ink);
  margin: .5rem 0 .75rem;
}

.page-about .chapter .chapter-lede {
  margin: 0 0 1.1rem;
  max-width: 44ch;
  font-size: clamp(1.02rem, 1.8vw, 1.2rem);
  line-height: 1.7;
  color: var(--ink);
}

.page-about .chapter-text {
  margin: 0 0 1rem;
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .pullquote {
  margin: clamp(1.5rem, 3vw, 2.25rem) 0;
  padding: 1.1rem 1.25rem 1.1rem 1.35rem;
  border-left: 2px solid var(--orange);
  border-radius: 0 var(--radius-m) var(--radius-m) 0;
  background: linear-gradient(90deg, rgba(13, 39, 69, .95), rgba(13, 39, 69, .5));
  font-family: var(--serif);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  line-height: 1.62;
  color: var(--serif-ink);
}

/* ---------- 里程碑时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0 0 0 1.5rem;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: .55rem;
  bottom: .8rem;
  width: 1px;
  background: linear-gradient(180deg, var(--orange), var(--cyan-deep) 55%, transparent);
}

.page-about .timeline-item {
  position: relative;
  padding-bottom: clamp(1.35rem, 3vw, 2rem);
  outline-offset: 6px;
}

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: -1.5rem;
  top: .5rem;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--night);
  border: 2px solid var(--cyan);
  transition: background-color .2s var(--ease), border-color .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .timeline-item:hover::before,
.page-about .timeline-item:focus::before,
.page-about .timeline-item:focus-within::before {
  background: var(--orange);
  border-color: var(--orange);
  box-shadow: 0 0 0 6px rgba(255, 106, 43, .16);
}

.page-about .timeline-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .7rem;
  margin: 0;
}

.page-about .timeline-year {
  font-family: var(--mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: 1.05rem;
  color: var(--cyan);
}

.page-about .timeline-name {
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--ink);
}

.page-about .timeline-text {
  margin: .35rem 0 0;
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .timeline-detail {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--cyan);
  transition: max-height .3s var(--ease), opacity .25s var(--ease), margin-top .3s var(--ease);
}

.page-about .timeline-item:hover .timeline-detail,
.page-about .timeline-item:focus .timeline-detail,
.page-about .timeline-item:focus-within .timeline-detail {
  max-height: 8rem;
  opacity: 1;
  margin-top: .4rem;
}

/* ---------- 团队 ---------- */
.page-about .role-grid {
  display: grid;
  gap: clamp(.85rem, 2vw, 1.15rem);
  margin: 1.35rem 0 clamp(1.35rem, 3vw, 2rem);
}

.page-about .role-card {
  padding: 1.15rem 1.15rem 1.3rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  background: var(--panel);
  transition: border-color .18s var(--ease), transform .18s var(--ease);
}

.page-about .role-card:hover {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .role-num {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: 1.75rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .role-name {
  margin: .5rem 0 .5rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
}

.page-about .role-card p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--muted);
}

@media (min-width: 760px) {
  .page-about .role-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 数据 ---------- */
.page-about .data-split {
  display: grid;
  gap: clamp(1.25rem, 3vw, 2rem);
  align-items: center;
  margin: 1.35rem 0 clamp(1.35rem, 3vw, 2rem);
}

.page-about .data-list {
  display: grid;
  gap: .9rem;
}

.page-about .data-item {
  padding: .15rem 0 .15rem .95rem;
  border-left: 2px solid var(--cyan-deep);
}

.page-about .data-item:nth-child(2) {
  border-left-color: var(--orange);
}

.page-about .data-value {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.2rem, 2.4vw, 1.6rem);
  line-height: 1.2;
  color: var(--ink);
}

.page-about .data-text {
  margin: .35rem 0 0;
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--muted);
}

@media (min-width: 860px) {
  .page-about .data-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, .85fr);
  }
}

/* ---------- 观赛记录 ---------- */
.page-about .record-list {
  list-style: none;
  margin: 1.35rem 0 clamp(1.2rem, 2.5vw, 1.75rem);
  padding: 0;
  display: grid;
  gap: clamp(1rem, 2.2vw, 1.4rem);
  counter-reset: record;
}

.page-about .record-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: .9rem;
  align-items: start;
  padding-bottom: clamp(1rem, 2.2vw, 1.4rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .record-item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .record-index {
  font-family: var(--mono);
  font-weight: 700;
  font-size: .875rem;
  letter-spacing: .06em;
  color: var(--orange);
  padding-top: .25rem;
  border-top: 2px solid var(--orange);
  min-width: 2.2rem;
}

.page-about .record-text {
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--ink);
  opacity: .88;
}

/* ---------- 共建 ---------- */
.page-about .community-grid {
  display: grid;
  gap: clamp(.9rem, 2vw, 1.25rem);
  margin-top: 1.35rem;
}

.page-about .community-card {
  padding: clamp(1.15rem, 2.4vw, 1.6rem);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-l);
  background: linear-gradient(160deg, rgba(13, 39, 69, .95), rgba(8, 32, 59, .95));
  transition: border-color .18s var(--ease);
}

.page-about .community-card:hover {
  border-color: var(--orange);
}

.page-about .community-num {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.75rem, 4vw, 2.4rem);
  line-height: 1;
  color: var(--orange-soft);
}

.page-about .community-name {
  margin: .6rem 0 .55rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
}

.page-about .community-card p {
  margin: 0 0 1rem;
  font-size: .9375rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .community-link {
  display: inline-block;
  font-size: .875rem;
  font-weight: 500;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(33, 230, 210, .4);
  padding-bottom: 1px;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}

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

@media (min-width: 760px) {
  .page-about .community-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 下一步入口 ---------- */
.page-about .about-next {
  margin-top: clamp(2rem, 5vw, 3.5rem);
  padding-top: clamp(1.5rem, 4vw, 2.5rem);
  border-top: 1px solid var(--line-soft);
}

.page-about .next-title {
  margin: 0 0 .6rem;
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.3rem, 2.6vw, 1.75rem);
  color: var(--serif-ink);
}

.page-about .next-lede {
  margin: 0 0 1.25rem;
  max-width: 48ch;
  font-size: .9688rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .next-grid {
  display: grid;
  gap: .75rem;
}

.page-about .next-link {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: .5rem 1rem;
  padding: 1rem 1.15rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  background: var(--panel);
  color: var(--ink);
  font-weight: 500;
  text-decoration: none;
  transition: border-color .18s var(--ease), background-color .18s var(--ease);
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  border-color: var(--orange);
  background: rgba(255, 106, 43, .08);
}

.page-about .next-hint {
  font-size: .8125rem;
  font-weight: 400;
  color: var(--muted);
}

@media (min-width: 700px) {
  .page-about .next-grid {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  }
}

/* ---------- 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .timeline-detail {
    transition: none;
  }

  .page-about .role-card:hover {
    transform: none;
  }

  .page-about .chapter-link,
  .page-about .next-link,
  .page-about .community-link {
    transition: none;
  }
}