.page-about {
  --about-hair: var(--grid-line);
  --about-panel: var(--navy-deck);
  --about-accent: var(--electric-cyan);
  --about-mark: var(--warm-gold);
  padding-bottom: clamp(3.5rem, 8vw, 6rem);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5rem;
  padding-top: clamp(1.25rem, 3vw, 2rem);
  padding-bottom: clamp(1rem, 2vw, 1.5rem);
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .04em;
}
.page-about .breadcrumbs__item {
  color: var(--slate-mist);
  text-decoration: none;
}
.page-about .breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  margin-right: .5rem;
  color: var(--muted-ink);
}
.page-about .breadcrumbs__item:hover {
  color: var(--electric-cyan);
}
.page-about .breadcrumbs__item[aria-current="page"] {
  color: var(--cream-paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(2.5rem, 6vw, 4.5rem);
}
.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3rem);
  border-top: 1px solid var(--grid-line);
  padding-top: clamp(1.75rem, 4vw, 3rem);
}
.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.4rem, 6.4vw, 4.1rem);
  line-height: 1.04;
  letter-spacing: -.01em;
  color: var(--cream-paper);
  margin: .5rem 0 0;
  max-width: 18ch;
}
.page-about .about-hero__sub {
  margin-top: clamp(1.1rem, 2.5vw, 1.6rem);
  max-width: 44ch;
  color: var(--slate-mist);
  line-height: 1.75;
}
.page-about .about-hero__note {
  margin-top: .9rem;
  max-width: 42ch;
  color: var(--cream-paper);
  font-size: .9375rem;
  line-height: 1.7;
  padding-left: 1rem;
  border-left: 2px solid var(--teal-deep);
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: clamp(1.5rem, 3vw, 2.25rem);
}

.page-about .about-hero__panel {
  background: var(--navy-deck);
  border: 1px solid var(--grid-line);
  padding: clamp(1.25rem, 3vw, 1.75rem);
  align-self: start;
}
.page-about .about-hero__panel-label {
  font-size: .75rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--warm-gold);
  margin: 0 0 1rem;
}
.page-about .fact-list {
  margin: 0;
  display: grid;
  gap: 0;
}
.page-about .fact-list__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: .85rem 0;
  border-bottom: 1px solid var(--grid-line);
}
.page-about .fact-list__row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}
.page-about .fact-list__row:first-child {
  padding-top: 0;
}
.page-about .fact-list dt {
  color: var(--slate-mist);
  font-size: .875rem;
}
.page-about .fact-list dd {
  margin: 0;
  color: var(--electric-cyan);
  font-size: 1.0625rem;
  font-weight: 700;
  white-space: nowrap;
}

/* ---------- 区块通用 ---------- */
.page-about .section {
  padding-top: clamp(2.75rem, 7vw, 5rem);
}
.page-about .section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .65rem 1.25rem;
  border-bottom: 1px solid var(--grid-line);
  padding-bottom: .9rem;
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}
.page-about .section__index {
  font-size: .8125rem;
  color: var(--about-accent);
  letter-spacing: .1em;
  margin: 0;
}
.page-about .section__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.6rem, 4vw, 2.1rem);
  letter-spacing: -.01em;
  color: var(--cream-paper);
  margin: 0;
}
.page-about .section__meta {
  margin: 0 0 0 auto;
  font-size: .8125rem;
  color: var(--slate-mist);
}

/* ---------- 01 起点 ---------- */
.page-about .origin-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3.5rem);
}
.page-about .origin-copy p {
  margin: 0 0 1.2rem;
  max-width: 62ch;
  color: var(--slate-mist);
  line-height: 1.78;
}
.page-about .origin-copy p:first-child {
  color: var(--cream-paper);
  font-size: 1.0625rem;
}
.page-about .origin-copy p:last-child {
  margin-bottom: 0;
}
.page-about .origin-visual .media-frame__caption {
  margin-top: .85rem;
  font-size: .8125rem;
  line-height: 1.65;
  color: var(--muted-ink);
}

/* ---------- 02 时间轴 ---------- */
.page-about .path-figure {
  margin-bottom: clamp(2rem, 5vw, 3.25rem);
}
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.5rem;
}
.page-about .timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 11px;
  width: 1px;
  background: var(--grid-line);
  pointer-events: none;
}
.page-about .tl-item {
  position: relative;
  padding-left: 2.25rem;
  outline: none;
}
.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: 6px;
  top: .55rem;
  width: 11px;
  height: 11px;
  background: var(--ink-abyss);
  border: 1px solid var(--grid-line);
  transition: background-color 240ms var(--ease), border-color 240ms var(--ease);
}
.page-about .tl-item:hover::before,
.page-about .tl-item:focus-visible::before {
  background: var(--warm-gold);
  border-color: var(--warm-gold);
}
.page-about .tl-item:focus-visible {
  outline: 2px solid var(--electric-cyan);
  outline-offset: 6px;
}
.page-about .tl-item__year {
  display: inline-block;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--electric-cyan);
  letter-spacing: .06em;
}
.page-about .tl-item__title {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--cream-paper);
  margin: .28rem 0 .45rem;
  letter-spacing: -.005em;
}
.page-about .tl-item__text {
  margin: 0;
  max-width: 46ch;
  color: var(--slate-mist);
  font-size: .9375rem;
  line-height: 1.72;
}
.page-about .tl-item__more {
  display: grid;
  grid-template-rows: 0fr;
  opacity: 0;
  transition: grid-template-rows 300ms var(--ease), opacity 300ms var(--ease);
}
.page-about .tl-item__more > p {
  overflow: hidden;
  margin: 0;
  max-width: 46ch;
  color: var(--cream-paper);
  font-size: .875rem;
  line-height: 1.75;
}
.page-about .tl-item__more > p::before {
  content: "";
  display: block;
  width: 2rem;
  height: 1px;
  background: var(--teal-deep);
  margin: .85rem 0 .6rem;
}
.page-about .tl-item:hover .tl-item__more,
.page-about .tl-item:focus-within .tl-item__more,
.page-about .tl-item:focus-visible .tl-item__more {
  grid-template-rows: 1fr;
  opacity: 1;
}

/* ---------- 03 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3rem);
}
.page-about .team-meters {
  display: grid;
  gap: clamp(1.25rem, 3vw, 1.75rem);
}
.page-about .team-meter {
  border-top: 1px solid var(--grid-line);
  padding-top: 1rem;
}
.page-about .team-meter__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: .75rem;
}
.page-about .team-meter__name {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--cream-paper);
  letter-spacing: -.005em;
}
.page-about .team-meter__num {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--warm-gold);
}
.page-about .team-meter__track {
  position: relative;
  height: 10px;
  background: var(--ink-abyss);
  border: 1px solid var(--grid-line);
  overflow: hidden;
}
.page-about .team-meter__fill {
  display: block;
  height: 100%;
  width: var(--pct, 0%);
  background: linear-gradient(90deg, var(--teal-deep), var(--electric-cyan));
  transform-origin: left center;
  animation: about-meter-grow 760ms var(--ease) both;
  animation-delay: var(--meter-delay, 0ms);
}
@keyframes about-meter-grow {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}
.page-about .team-meter__desc {
  margin: .85rem 0 0;
  max-width: 52ch;
  color: var(--slate-mist);
  font-size: .9375rem;
  line-height: 1.72;
}

/* ---------- 04 内容体系 ---------- */
.page-about .system-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4vw, 3rem);
}
.page-about .system-copy p {
  margin: 0 0 1.2rem;
  max-width: 58ch;
  color: var(--slate-mist);
  line-height: 1.78;
}
.page-about .system-copy p:last-child {
  margin-bottom: 0;
}
.page-about .system-index {
  background: var(--navy-deck);
  border: 1px solid var(--grid-line);
  padding: clamp(1.1rem, 3vw, 1.6rem);
}
.page-about .system-index__label {
  margin: 0 0 .9rem;
  font-size: .75rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--warm-gold);
}
.page-about .system-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}
.page-about .system-index__item {
  border-top: 1px solid var(--grid-line);
}
.page-about .system-index__item:first-child {
  border-top: 0;
}
.page-about .system-index__item a {
  display: grid;
  grid-template-columns: 2.25rem 1fr;
  grid-template-rows: auto auto;
  column-gap: .75rem;
  align-items: baseline;
  padding: .9rem .25rem;
  min-height: 44px;
  text-decoration: none;
  transition: transform 200ms var(--ease), background-color 200ms var(--ease);
}
.page-about .system-index__item a:hover,
.page-about .system-index__item a:focus-visible {
  transform: translate(-4px, -4px);
  background: rgba(31, 224, 232, .06);
  outline: 1px solid var(--electric-cyan);
}
.page-about .system-index__num {
  grid-row: 1 / span 2;
  font-size: .8125rem;
  color: var(--electric-cyan);
  letter-spacing: .08em;
}
.page-about .system-index__name {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--cream-paper);
}
.page-about .system-index__hint {
  grid-column: 2;
  font-size: .8125rem;
  color: var(--muted-ink);
  line-height: 1.6;
}

/* ---------- 05 合作与荣誉 ---------- */
.page-about .partners-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.5rem, 4vw, 2.75rem);
  align-items: start;
}
.page-about .partners-tags {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
}
.page-about .partners-tags .tag {
  border-radius: 2px;
}
.page-about .partners-copy {
  margin: 0;
  max-width: 52ch;
  color: var(--slate-mist);
  line-height: 1.78;
}
.page-about .honor {
  display: flex;
  align-items: flex-start;
  gap: .9rem;
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  padding: 1rem 1.15rem;
  background: var(--navy-deck);
  border: 1px solid var(--grid-line);
  border-left: 3px solid var(--signal-rust);
}
.page-about .honor__mark {
  flex: 0 0 auto;
  width: 10px;
  height: 10px;
  margin-top: .45rem;
  background: var(--warm-gold);
}
.page-about .honor__text {
  margin: 0;
  color: var(--cream-paper);
  font-size: .9375rem;
  line-height: 1.72;
}
.page-about .honor__text strong {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--warm-gold);
  margin-right: .25rem;
}

/* ---------- 06 规模 ---------- */
.page-about .scale-band {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--grid-line);
  border: 1px solid var(--grid-line);
}
.page-about .scale-cell {
  background: var(--navy-deck);
  padding: clamp(1.1rem, 3vw, 1.75rem);
  display: grid;
  gap: .4rem;
}
.page-about .scale-cell__num {
  font-size: clamp(1.75rem, 5vw, 2.4rem);
  font-weight: 700;
  color: var(--electric-cyan);
  letter-spacing: -.01em;
  line-height: 1;
}
.page-about .scale-cell__num small {
  font-size: .4375em;
  margin-left: .2em;
  color: var(--slate-mist);
  font-weight: 700;
}
.page-about .scale-cell__label {
  color: var(--slate-mist);
  font-size: .875rem;
  line-height: 1.65;
}
.page-about .scale-foot {
  margin: clamp(1.5rem, 3vw, 2rem) 0 0;
  max-width: 68ch;
  color: var(--slate-mist);
  font-size: .9375rem;
  line-height: 1.78;
}
.page-about .scale-foot a {
  color: var(--electric-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--teal-deep);
}
.page-about .scale-foot a:hover,
.page-about .scale-foot a:focus-visible {
  border-bottom-color: var(--electric-cyan);
}

/* ---------- 媒体容器 ---------- */
.page-about .media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--grid-line);
  background: var(--navy-deck);
}
.page-about .media-frame img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}
.page-about .media-frame--slant img {
  clip-path: polygon(0 0, 100% 4%, 100% 100%, 0 96%);
}

/* ---------- 窄屏保护 ---------- */
@media (max-width: 380px) {
  .page-about .about-hero__title {
    font-size: 2.1rem;
  }
  .page-about .scale-band {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* ---------- 平板 ---------- */
@media (min-width: 760px) {
  .page-about .origin-grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
  .page-about .team-grid {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }
  .page-about .system-grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
  .page-about .partners-grid {
    grid-template-columns: 6fr 6fr;
  }
  .page-about .scale-band {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 桌面：斜向交错时间轴 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 4fr;
    column-gap: clamp(2rem, 5vw, 5rem);
  }

  .page-about .timeline {
    display: block;
    position: relative;
    padding: 1rem 0 .5rem;
  }
  .page-about .timeline::before {
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    width: auto;
    height: auto;
    background: linear-gradient(
      to bottom right,
      transparent calc(50% - 1px),
      var(--grid-line) calc(50% - 1px),
      var(--grid-line) calc(50% + 1px),
      transparent calc(50% + 1px)
    );
  }
  .page-about .tl-item {
    width: 44%;
    padding: 1.75rem 0 1.75rem 0;
    margin-bottom: 1.25rem;
  }
  .page-about .tl-item:nth-child(odd) {
    margin-right: auto;
    margin-left: 0;
  }
  .page-about .tl-item:nth-child(even) {
    margin-left: auto;
    margin-right: 0;
  }
  .page-about .tl-item::before {
    top: 2.1rem;
    width: 13px;
    height: 13px;
  }
  .page-about .tl-item:nth-child(odd)::before {
    left: auto;
    right: -1.6rem;
  }
  .page-about .tl-item:nth-child(even)::before {
    left: -1.6rem;
  }
  .page-about .tl-item:hover,
  .page-about .tl-item:focus-visible {
    transform: translate(-4px, -4px);
    transition: transform 200ms var(--ease);
  }
  .page-about .path-figure {
    max-width: 940px;
    margin-left: auto;
    margin-right: auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-meter__fill {
    animation: none;
  }
  .page-about .tl-item__more,
  .page-about .system-index__item a,
  .page-about .tl-item::before {
    transition: none;
  }
  .page-about .tl-item:hover,
  .page-about .tl-item:focus-visible {
    transform: none;
  }
}

.page-about {
  --meter-delay: inherit;
  --pct: 1rem;
}