.page-about {
  color: var(--paper);
  background: var(--ink-800);
  padding-bottom: clamp(40px, 7vw, 80px);
}

.page-about .breadcrumb {
  padding: clamp(16px, 3vw, 26px) 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
}

.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
}

.page-about .breadcrumb a:hover {
  color: var(--lime);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: clamp(26px, 5vw, 54px) 0 clamp(28px, 5vw, 52px);
  border-bottom: 1px solid var(--rule);
  background:
    radial-gradient(120% 90% at 12% -10%, rgba(198, 242, 78, .10) 0%, transparent 55%),
    radial-gradient(90% 70% at 100% 0%, rgba(255, 138, 61, .07) 0%, transparent 60%),
    var(--ink-800);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background: linear-gradient(90deg, var(--lime) 0%, rgba(198, 242, 78, .18) 32%, transparent 68%);
}

.page-about .about-hero .eyebrow {
  display: block;
  margin: 0 0 clamp(14px, 2.4vw, 22px);
}

.page-about .about-hero__title {
  margin: 0;
  max-width: 20ch;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.85rem, 6.2vw, 3.6rem);
  line-height: 1.08;
  letter-spacing: -.012em;
  text-wrap: balance;
}

.page-about .about-hero__mark {
  color: var(--lime);
  padding-right: .12em;
}

.page-about .about-hero__lede {
  margin: clamp(16px, 2.6vw, 24px) 0 0;
  max-width: 58ch;
  color: var(--mist);
  font-size: clamp(.95rem, 1.6vw, 1.06rem);
  line-height: 1.78;
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(24px, 4vw, 40px);
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .about-figure {
  background: var(--ink-800);
  padding: 14px 16px 16px;
}

.page-about .about-figure__num {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.25rem, 3.4vw, 1.7rem);
  line-height: 1.1;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-figure__label {
  margin: 6px 0 0;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--mist);
  letter-spacing: .02em;
}

/* ---------- 档案行 ---------- */

.page-about .dossier-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: clamp(30px, 5.5vw, 60px) 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .dossier-row--last {
  border-bottom: 0;
}

.page-about .dossier-row__tick {
  display: inline-block;
  padding-top: 8px;
  border-top: 1px solid var(--lime);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .09em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.page-about .dossier-row__body {
  min-width: 0;
}

.page-about .dossier-row__body > p {
  max-width: 66ch;
  margin: 0 0 12px;
  color: var(--mist);
  line-height: 1.78;
}

.page-about .dossier-row__body .serif-title {
  margin: 0 0 clamp(12px, 2vw, 18px);
  font-size: clamp(1.32rem, 3.2vw, 1.85rem);
  line-height: 1.3;
}

.page-about .about-note a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(198, 242, 78, .45);
}

.page-about .about-note a:hover {
  border-bottom-color: var(--lime);
}

/* ---------- 起点分栏 ---------- */

.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3.4vw, 34px);
}

.page-about .about-split__text p {
  margin: 0 0 14px;
  color: var(--mist);
  line-height: 1.8;
}

.page-about .about-media,
.page-about .about-media-wide,
.page-about .about-media-team {
  margin: 0;
}

.page-about .about-media img,
.page-about .about-media-wide img,
.page-about .about-media-team img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--rule);
  background: var(--panel);
}

.page-about .about-media-wide {
  margin-top: clamp(24px, 3.6vw, 36px);
}

.page-about .about-media-team {
  margin-top: clamp(24px, 3.6vw, 36px);
}

/* ---------- 版本刻度图 ---------- */

.page-about .phase-jump {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 16px 0 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--dim);
}

.page-about .phase-jump a {
  display: inline-block;
  padding: 3px 9px;
  border: 1px solid var(--rule);
  color: var(--mist);
  text-decoration: none;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .phase-jump a:hover,
.page-about .phase-jump a:focus-visible {
  color: var(--ink-900);
  background: var(--lime);
  border-color: var(--lime);
  outline: none;
}

.page-about .phase-list {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .phase {
  position: relative;
  padding: 22px 12px 22px 0;
  border-top: 2px solid var(--rule);
  transition: border-color .18s var(--ease), background .18s var(--ease);
}

.page-about .phase__node {
  position: absolute;
  top: -5px;
  left: 0;
  width: 8px;
  height: 8px;
  background: var(--rule);
  transform: rotate(45deg);
  transition: background .18s var(--ease);
}

.page-about .phase__ver {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--lime);
}

.page-about .phase__name {
  margin: 0 0 8px;
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--paper);
  letter-spacing: .01em;
}

.page-about .phase__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .phase:target,
.page-about .phase:hover {
  border-top-color: var(--lime);
  background: linear-gradient(180deg, rgba(198, 242, 78, .08), transparent 78%);
}

.page-about .phase:target .phase__node,
.page-about .phase:hover .phase__node {
  background: var(--lime);
}

/* ---------- 团队三栏 ---------- */

.page-about .team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(20px, 3vw, 28px);
  background: var(--rule);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.page-about .team__col {
  background: var(--ink-800);
  padding: 22px 4px 26px;
}

.page-about .team__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--dim);
  font-variant-numeric: tabular-nums;
}

.page-about .team__name {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.05rem, 2.4vw, 1.22rem);
  line-height: 1.4;
  color: var(--paper);
}

.page-about .team__text {
  margin: 0;
  font-size: .91rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 流程清单 ---------- */

.page-about .flow {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
}

.page-about .flow--plain {
  margin-top: 14px;
}

.page-about .flow__item {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  column-gap: 12px;
  padding: 16px 0;
  border-top: 1px solid var(--rule);
}

.page-about .flow__item:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .flow__num {
  grid-row: 1 / span 2;
  align-self: start;
  padding-top: 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .flow__title {
  margin: 0 0 4px;
  font-size: .98rem;
  font-weight: 600;
  color: var(--paper);
}

.page-about .flow__item p {
  margin: 0;
  font-size: .9rem;
  line-height: 1.74;
  color: var(--mist);
}

.page-about .about-sub {
  margin: clamp(28px, 4vw, 40px) 0 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.05rem, 2.6vw, 1.24rem);
  line-height: 1.45;
  color: var(--paper);
}

/* ---------- 合作索引 ---------- */

.page-about .partners {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
}

.page-about .partners__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 16px 0;
  border-top: 1px solid var(--rule);
}

.page-about .partners__item:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .partners__key {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .partners__desc {
  font-size: .92rem;
  line-height: 1.76;
  color: var(--mist);
}

.page-about .partners__desc strong {
  color: var(--paper);
  font-weight: 600;
}

/* ---------- 规模 ---------- */

.page-about .scale {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(18px, 3vw, 26px) 0 clamp(18px, 3vw, 24px);
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .scale__cell {
  background: var(--panel);
  padding: 18px 16px 20px;
}

.page-about .scale__num {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.15rem, 3vw, 1.5rem);
  line-height: 1.15;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .scale__label {
  margin: 7px 0 0;
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--mist);
}

/* ---------- 结尾行动区 ---------- */

.page-about .about-cta {
  margin-top: clamp(8px, 2vw, 18px);
  padding: clamp(34px, 6vw, 64px) 0;
  border-top: 1px solid var(--rule);
}

.page-about .about-cta__title {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.3rem, 3.4vw, 1.9rem);
  line-height: 1.3;
}

.page-about .about-cta__text {
  max-width: 60ch;
  margin: 0 0 clamp(20px, 3.4vw, 28px);
  line-height: 1.78;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta__ghost {
  border-color: rgba(11, 20, 16, .38);
  color: var(--ink-800);
}

.page-about .about-cta__ghost:hover,
.page-about .about-cta__ghost:focus-visible {
  border-color: var(--ink-800);
  color: var(--ink-900);
}

/* ---------- 断点 ---------- */

@media (min-width: 620px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .partners__item {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }

  .page-about .scale {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .phase-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 20px;
  }

  .page-about .phase {
    padding-right: 0;
  }

  .page-about .team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .team__col {
    padding: 26px 22px 30px;
  }

  .page-about .team__col:first-child {
    padding-left: 0;
  }

  .page-about .team__col:last-child {
    padding-right: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }

  .page-about .dossier-row {
    grid-template-columns: 108px minmax(0, 1fr);
    gap: clamp(22px, 3.6vw, 52px);
    padding: clamp(40px, 5vw, 66px) 0;
  }

  .page-about .dossier-row__rail {
    position: sticky;
    top: calc(var(--header-h) + 26px);
    align-self: start;
  }

  .page-about .dossier-row__tick {
    white-space: normal;
    line-height: 1.5;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .phase,
  .page-about .phase__node,
  .page-about .phase-jump a {
    transition: none;
  }
}