.page-about {
  --about-pad: clamp(48px, 7vw, 96px);
  --about-gap: clamp(20px, 3.2vw, 40px);
  background: var(--night);
  color: var(--ink);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs-wrap {
  padding-block: clamp(14px, 2vw, 20px) 0;
}
.page-about .about-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--steel);
}
.page-about .about-crumbs__link {
  color: var(--steel);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast), border-color var(--t-fast);
}
.page-about .about-crumbs__link:hover,
.page-about .about-crumbs__link:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}
.page-about .about-crumbs__sep {
  color: var(--line);
}
.page-about .about-crumbs__here {
  color: var(--ink);
}

/* ---------- 页头 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(26px, 4vw, 52px) clamp(42px, 6vw, 78px);
  background: linear-gradient(180deg, var(--night) 0%, var(--night) 58%, var(--pitch) 100%);
  overflow: hidden;
}
.page-about .about-hero__grid {
  display: grid;
  gap: clamp(26px, 4vw, 52px);
  align-items: center;
}
.page-about .about-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(32px, 6.2vw, 66px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ivory);
}
.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--ink);
}
.page-about .about-hero__strip {
  list-style: none;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}
.page-about .about-stat {
  padding: 14px 16px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(6, 10, 15, 0.55);
}
.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(23px, 3.4vw, 34px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lime);
}
.page-about .about-stat__label {
  display: block;
  margin-top: 7px;
  font-size: 12px;
  letter-spacing: 0.11em;
  color: var(--steel);
}
.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  overflow: hidden;
}
.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}
.page-about .about-hero__tag {
  position: absolute;
  right: 0;
  bottom: 0;
  padding: 9px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--carbon);
  background: var(--lime);
}

/* ---------- 目录条 ---------- */
.page-about .about-index {
  background: var(--carbon);
  border-block: 1px solid var(--line);
}
.page-about .about-index__inner {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-block: 10px;
}
.page-about .about-index__label {
  flex: 0 0 auto;
  padding-right: 14px;
  border-right: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--steel);
}
.page-about .about-index__scroll {
  flex: 1 1 auto;
  min-width: 0;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .about-index__scroll::-webkit-scrollbar {
  display: none;
}
.page-about .about-index__list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 12px;
  border: 1px solid transparent;
  font-size: 13px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--steel);
  transition: color var(--t-fast), border-color var(--t-fast), background var(--t-fast);
}
.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--lime);
  border-color: var(--line);
}
.page-about .about-index__link.is-current {
  color: var(--carbon);
  background: var(--lime);
  border-color: var(--lime);
}
.page-about .about-index__no {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--lime);
}
.page-about .about-index__link.is-current .about-index__no {
  color: var(--carbon);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  position: relative;
  padding-block: var(--about-pad);
}
.page-about .about-section--night {
  background: var(--night);
}
.page-about .about-section--pitch {
  background: var(--pitch);
}
.page-about .about-section--carbon {
  background: var(--carbon);
}
.page-about .about-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: clamp(22px, 4vw, 54px);
  pointer-events: none;
}
.page-about .about-section--pitch::before {
  background: linear-gradient(to bottom right, var(--carbon) 0 50%, transparent 50%);
}
.page-about .about-section--night::before {
  background: linear-gradient(to bottom right, var(--pitch) 0 50%, transparent 50%);
}
.page-about .about-section--carbon::before {
  background: linear-gradient(to bottom right, var(--night) 0 50%, transparent 50%);
}

.page-about .about-head {
  display: grid;
  gap: clamp(12px, 2.2vw, 28px);
  padding-bottom: clamp(18px, 3vw, 32px);
  margin-bottom: clamp(26px, 4vw, 50px);
  border-bottom: 1px solid var(--line);
}
.page-about .about-head__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(50px, 10vw, 102px);
  line-height: 0.8;
  letter-spacing: -0.05em;
  color: var(--line);
  transition: color var(--t-mid);
}
.page-about .about-section.is-current .about-head__num {
  color: var(--lime);
}
.page-about .about-head__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--ivory);
}
.page-about .about-head__lede {
  margin: 12px 0 0;
  max-width: 64ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--steel);
}

/* ---------- 01 平台定位 ---------- */
.page-about .topic-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .topic-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(20px, 2.6vw, 30px);
  background: var(--carbon);
}
.page-about .topic-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--lime);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform var(--t-mid);
}
.page-about .topic-card:hover::before,
.page-about .topic-card:focus-within::before {
  transform: scaleY(1);
}
.page-about .topic-card__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}
.page-about .topic-card__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(19px, 2.2vw, 24px);
  line-height: 1.26;
  color: var(--ivory);
}
.page-about .topic-card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.74;
  color: var(--ink);
}
.page-about .topic-card__meta {
  margin: auto 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.6;
  color: var(--steel);
}

/* ---------- 02 发展历程 ---------- */
.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}
.page-about .timeline__item {
  position: relative;
  padding-left: clamp(26px, 4vw, 48px);
  padding-bottom: clamp(26px, 3.6vw, 44px);
}
.page-about .timeline__item:last-child {
  padding-bottom: 0;
}
.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 9px;
  height: 9px;
  border: 1px solid var(--lime);
  background: var(--night);
  transform: rotate(45deg);
}
.page-about .timeline__year {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--lime);
}
.page-about .timeline__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(19px, 2.4vw, 28px);
  line-height: 1.2;
  color: var(--ivory);
}
.page-about .timeline__text {
  margin: 10px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--ink);
}

/* ---------- 03 数据来源 ---------- */
.page-about .flow-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--night);
}
.page-about .flow-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1400 / 720;
  object-fit: cover;
}
.page-about .flow-figure figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--steel);
}
.page-about .flow-steps {
  list-style: none;
  margin: clamp(22px, 3.4vw, 38px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .flow-step {
  padding: clamp(18px, 2.4vw, 28px);
  background: var(--night);
}
.page-about .flow-step__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}
.page-about .flow-step__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(18px, 2vw, 22px);
  color: var(--ivory);
}
.page-about .flow-step__text {
  margin: 9px 0 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--ink);
}

/* ---------- 04 团队与值守 ---------- */
.page-about .team-grid {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
}
.page-about .team-col {
  min-width: 0;
}
.page-about .team-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .team-fact {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 16px;
  background: var(--carbon);
}
.page-about .team-fact__num {
  flex: 0 0 auto;
  min-width: 2.2em;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lime);
}
.page-about .team-fact__label {
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
}
.page-about .duty {
  margin-top: clamp(20px, 3vw, 32px);
  border: 1px solid var(--line);
  background: var(--carbon);
}
.page-about .duty__head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px;
  margin: 0;
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--steel);
}
.page-about .duty__bar {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.page-about .duty__seg {
  position: relative;
  padding: 40px 14px 16px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--carbon);
  outline-offset: -2px;
  transition: background var(--t-fast);
}
.page-about .duty__seg::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 3px;
  transition: height var(--t-fast);
}
.page-about .duty__seg--s1::before {
  background: rgba(198, 255, 61, 0.26);
}
.page-about .duty__seg--s2::before {
  background: rgba(198, 255, 61, 0.5);
}
.page-about .duty__seg--s3::before {
  background: rgba(198, 255, 61, 0.74);
}
.page-about .duty__seg--s4::before {
  background: var(--lime);
}
.page-about .duty__seg:hover,
.page-about .duty__seg:focus-visible,
.page-about .duty__seg:focus-within {
  background: var(--pitch);
}
.page-about .duty__seg:hover::before,
.page-about .duty__seg:focus-visible::before,
.page-about .duty__seg:focus-within::before {
  height: 6px;
}
.page-about .duty__time {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 14px;
  color: var(--ivory);
}
.page-about .duty__name {
  display: block;
  margin-top: 7px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--steel);
}
.page-about .duty__note {
  margin: 0;
  padding: 13px 16px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--steel);
}
.page-about .team-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--carbon);
  align-self: start;
}
.page-about .team-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}
.page-about .team-figure figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--steel);
}

/* ---------- 05 用户覆盖 ---------- */
.page-about .reach-grid {
  display: grid;
  gap: clamp(22px, 3.2vw, 38px);
}
.page-about .reach-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .reach-stat {
  padding: clamp(18px, 2.6vw, 30px);
  background: var(--night);
}
.page-about .reach-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(28px, 4.6vw, 46px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--ivory);
}
.page-about .reach-stat__num em {
  font-style: normal;
  font-size: 0.48em;
  margin-left: 4px;
  color: var(--lime);
}
.page-about .reach-stat__label {
  display: block;
  margin-top: 9px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--steel);
}
.page-about .reach-side {
  min-width: 0;
}
.page-about .reach-side__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(18px, 2.2vw, 24px);
  color: var(--ivory);
}
.page-about .region-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}
.page-about .region-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .region-row__name {
  flex: 0 0 auto;
  min-width: 3.6em;
  font-size: 15px;
  color: var(--ink);
}
.page-about .region-row__bar {
  position: relative;
  flex: 1 1 auto;
  min-width: 48px;
  height: 4px;
  background: var(--line);
}
.page-about .region-row__bar::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: var(--w, 50%);
  background: var(--lime);
}
.page-about .region-row__bar--a {
  --w: 100%;
}
.page-about .region-row__bar--b {
  --w: 86%;
}
.page-about .region-row__bar--c {
  --w: 74%;
}
.page-about .region-row__val {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--steel);
}
.page-about .reach-side__note {
  margin: 16px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--steel);
}

/* ---------- 06 内容协作 ---------- */
.page-about .next-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.page-about .next-card {
  background: var(--night);
}
.page-about .next-card__link {
  display: flex;
  flex-direction: column;
  gap: 9px;
  height: 100%;
  padding: clamp(18px, 2.4vw, 26px);
  text-decoration: none;
  transition: background var(--t-fast);
}
.page-about .next-card__link:hover,
.page-about .next-card__link:focus-visible {
  background: var(--pitch);
}
.page-about .next-card__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}
.page-about .next-card__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(17px, 1.9vw, 21px);
  line-height: 1.28;
  color: var(--ivory);
}
.page-about .next-card__text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
}
.page-about .next-card__cta {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--lime);
}
.page-about .next-card__link:hover .next-card__cta,
.page-about .next-card__link:focus-visible .next-card__cta {
  color: var(--lime);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .flow-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .duty__bar {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .duty__seg:last-child {
    border-right: 0;
  }
}

@media (min-width: 860px) {
  .page-about .about-head {
    grid-template-columns: minmax(84px, 150px) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .reach-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, 0.96fr);
  }
  .page-about .about-hero__figure {
    clip-path: polygon(7% 0, 100% 0, 100% 100%, 0 100%);
  }
  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    align-items: start;
  }
  .page-about .team-figure {
    position: sticky;
    top: 96px;
  }
}

@media (min-width: 1080px) {
  .page-about .next-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .topic-card::before,
  .page-about .about-head__num,
  .page-about .duty__seg::before,
  .page-about .next-card__link {
    transition: none;
  }
}