.page-about {
  --ab-rail: 104px;
  --ab-gap: 56px;
  --ab-cut: polygon(0 0, 100% 0, 100% calc(100% - 32px), calc(100% - 32px) 100%, 0 100%);
  display: block;
  background: var(--ink-green);
  color: var(--paper);
  font-family: var(--font-sans);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin: 0 0 26px;
  font-size: var(--step-1);
}

.page-about .crumbs__item + .crumbs__item {
  margin-left: 8px;
}

.page-about .crumbs__item + .crumbs__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .crumbs__link {
  color: var(--sage);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s ease, border-color .18s ease;
}

.page-about .crumbs__link:hover,
.page-about .crumbs__link:focus-visible {
  color: var(--neon-cyan);
  border-bottom-color: var(--neon-cyan);
}

.page-about .crumbs__current {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 26px 0 52px;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(115% 85% at 92% -12%, rgba(47, 227, 200, 0.16), transparent 60%),
    linear-gradient(175deg, var(--charcoal) 0%, var(--ink-green) 76%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 30px;
}

.page-about .about-hero__kicker {
  display: inline-block;
  margin: 0 0 18px;
  padding: 5px 14px 5px 12px;
  font-size: var(--step-1);
  letter-spacing: .1em;
  color: var(--ink-green);
  background: var(--neon-cyan);
  clip-path: polygon(0 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
}

.page-about .about-hero__title {
  margin: 0 0 20px;
  font-size: clamp(36px, 9.5vw, 64px);
  line-height: 1.04;
  letter-spacing: -.025em;
  font-weight: 900;
  color: var(--paper);
}

.page-about .about-hero__lede {
  max-width: 38ch;
  margin: 0 0 26px;
  font-size: var(--step0);
  line-height: 1.78;
  color: rgba(242, 247, 245, .84);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-hero__side {
  padding: 18px 18px 8px;
  border: 1px solid var(--line);
  background: rgba(16, 19, 20, .6);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .about-hero__sideLabel {
  margin: 0 0 10px;
  font-size: var(--step-1);
  letter-spacing: .2em;
  color: var(--sage);
}

.page-about .about-hero__stats {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__stats li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 0;
  border-top: 1px solid var(--line);
}

.page-about .about-hero__value {
  flex: 0 0 auto;
  font-family: var(--font-num);
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--neon-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__unit {
  font-size: var(--step-1);
  color: var(--sage);
}

/* ---------- 轨道 + 正文骨架 ---------- */
.page-about .about-body {
  display: grid;
  gap: 0;
  padding-bottom: 80px;
}

.page-about .about-rail {
  position: sticky;
  top: 0;
  z-index: 5;
  padding: 10px 0 12px;
  background: var(--ink-green);
  border-bottom: 1px solid var(--line);
}

.page-about .about-rail__cap {
  display: none;
  margin: 0 0 14px;
  font-size: var(--step-1);
  letter-spacing: .2em;
  color: var(--sage);
}

.page-about .about-rail__list {
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scrollbar-width: none;
}

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

.page-about .about-rail__link {
  display: block;
  padding: 6px 10px 6px 12px;
  font-family: var(--font-num);
  font-size: var(--step1);
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--sage);
  text-decoration: none;
  white-space: nowrap;
  border-left: 2px solid transparent;
  font-variant-numeric: tabular-nums;
  transition: color .18s ease, border-color .18s ease, background-color .18s ease;
}

.page-about .about-rail__link:hover {
  color: var(--neon-cyan);
  background: rgba(47, 227, 200, .07);
  border-left-color: var(--neon-cyan);
}

.page-about .about-rail__link:focus-visible {
  outline: 2px solid var(--neon-cyan);
  outline-offset: 2px;
  color: var(--neon-cyan);
}

/* ---------- 章节 ---------- */
.page-about .ab-sec {
  padding-top: 44px;
  margin-top: 44px;
  border-top: 1px solid var(--line);
}

.page-about .ab-sec__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 16px;
  align-items: start;
  margin-bottom: 22px;
}

.page-about .ab-sec__num {
  margin: 0;
  font-family: var(--font-num);
  font-size: clamp(40px, 12vw, 82px);
  font-weight: 800;
  line-height: .82;
  letter-spacing: -.05em;
  color: var(--deep-green);
  -webkit-text-stroke: 1.5px rgba(47, 227, 200, .45);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-sec__note {
  margin: 0 0 8px;
  font-size: var(--step-1);
  letter-spacing: .16em;
  color: var(--neon-cyan);
}

.page-about .ab-sec__title {
  margin: 0;
  font-size: clamp(23px, 5vw, 34px);
  line-height: 1.22;
  letter-spacing: -.015em;
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-sec__intro,
.page-about .ab-sec__tail {
  max-width: 50ch;
  margin: 0 0 20px;
  font-size: 15.5px;
  line-height: 1.78;
  color: rgba(242, 247, 245, .8);
}

.page-about .ab-sec__tail {
  margin: 20px 0 0;
}

.page-about .ab-sec__tail a {
  color: var(--neon-cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .ab-sec__body p {
  max-width: 46ch;
  margin: 0 0 16px;
  font-size: var(--step0);
  line-height: 1.8;
  color: rgba(242, 247, 245, .84);
}

.page-about .ab-sec__lead {
  font-size: var(--step1);
  line-height: 1.7;
  color: var(--paper);
}

/* ---------- 图片 ---------- */
.page-about .ab-fig {
  margin: 26px 0 0;
}

.page-about .ab-fig img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .ab-fig figcaption {
  margin-top: 10px;
  font-size: var(--step-1);
  line-height: 1.6;
  color: var(--sage);
}

.page-about .ab-fig--wide img {
  aspect-ratio: 16 / 9;
}

.page-about .ab-fig--cut {
  position: relative;
}

.page-about .ab-fig--cut img {
  aspect-ratio: 3 / 2;
  border: 0;
  clip-path: var(--ab-cut);
}

.page-about .ab-fig--cut::after {
  content: "";
  position: absolute;
  inset: 0;
  clip-path: var(--ab-cut);
  background: linear-gradient(200deg, rgba(47, 227, 200, .16), transparent 46%);
  pointer-events: none;
}

/* ---------- 三层内容 ---------- */
.page-about .ab-split {
  display: grid;
  gap: 28px;
}

.page-about .ab-layers {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-layers__item {
  position: relative;
  padding: 18px 20px 18px 24px;
  background: var(--deep-green);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .ab-layers__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 14px;
  width: 3px;
  background: var(--neon-cyan);
}

.page-about .ab-layers__tag {
  display: inline-block;
  margin-bottom: 9px;
  padding: 2px 10px 2px 8px;
  font-size: var(--step-1);
  letter-spacing: .12em;
  color: var(--ink-green);
  background: var(--neon-cyan);
  clip-path: polygon(0 0, 100% 0, calc(100% - 8px) 100%, 0 100%);
}

.page-about .ab-layers__tag--signal {
  color: var(--charcoal);
  background: var(--signal-orange);
}

.page-about .ab-layers__title {
  margin: 0 0 6px;
  font-size: var(--step1);
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-layers__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(242, 247, 245, .78);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 14px;
  margin-top: 4px;
}

.page-about .ab-team__item {
  padding: 20px;
  background: var(--charcoal);
  border: 1px solid var(--line);
  border-top: 2px solid var(--neon-cyan);
}

.page-about .ab-team__n {
  margin: 0;
  font-family: var(--font-num);
  font-size: 40px;
  font-weight: 700;
  line-height: 1;
  color: var(--neon-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-team__role {
  margin: 10px 0 8px;
  font-size: var(--step1);
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-team__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: rgba(242, 247, 245, .76);
}

.page-about .ab-fig--work {
  margin-top: 24px;
}

/* ---------- 数据条 ---------- */
.page-about .ab-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 6px 0 4px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-metrics__item {
  padding: 18px 16px;
  background: var(--ink-green);
}

.page-about .ab-metrics__n {
  margin: 0 0 6px;
  font-family: var(--font-num);
  font-size: clamp(26px, 7vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-metrics__l {
  margin: 0;
  font-size: var(--step-1);
  letter-spacing: .06em;
  color: var(--sage);
}

/* ---------- 年份时间轴 ---------- */
.page-about .ab-tl {
  position: relative;
  margin: 6px 0 0;
  padding: 0 0 0 24px;
  list-style: none;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--neon-cyan) 0%, var(--line) 28%, var(--line) 100%);
}

.page-about .ab-tl > li {
  position: relative;
  margin-bottom: 4px;
}

.page-about .ab-tl > li::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 20px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--neon-cyan);
  box-shadow: 0 0 0 4px rgba(47, 227, 200, .14);
}

.page-about .ab-tl__node {
  border-bottom: 1px solid var(--line);
  scroll-margin-top: 96px;
}

.page-about .ab-tl__sum {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 14px;
  padding: 14px 0;
  cursor: pointer;
  list-style: none;
}

.page-about .ab-tl__sum::-webkit-details-marker {
  display: none;
}

.page-about .ab-tl__sum::marker {
  content: "";
}

.page-about .ab-tl__year {
  font-family: var(--font-num);
  font-size: var(--step2);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.01em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-tl__name {
  font-size: var(--step0);
  color: rgba(242, 247, 245, .78);
}

.page-about .ab-tl__node[open] > .ab-tl__sum .ab-tl__name {
  color: var(--neon-cyan);
}

.page-about .ab-tl__mark {
  position: relative;
  flex: 0 0 auto;
  align-self: center;
  width: 18px;
  height: 18px;
  margin-left: auto;
  border: 1px solid var(--line);
}

.page-about .ab-tl__mark::before,
.page-about .ab-tl__mark::after {
  content: "";
  position: absolute;
  background: var(--neon-cyan);
  transition: transform .2s ease, opacity .2s ease;
}

.page-about .ab-tl__mark::before {
  left: 4px;
  right: 4px;
  top: 8px;
  height: 1.5px;
}

.page-about .ab-tl__mark::after {
  top: 4px;
  bottom: 4px;
  left: 8px;
  width: 1.5px;
}

.page-about .ab-tl__node[open] .ab-tl__mark::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .ab-tl__body {
  padding: 0 0 20px;
}

.page-about .ab-tl__body p {
  max-width: 52ch;
  margin: 0;
  padding-left: 14px;
  border-left: 2px solid var(--deep-green);
  font-size: 15.5px;
  line-height: 1.78;
  color: rgba(242, 247, 245, .74);
}

/* ---------- 合作 ---------- */
.page-about .ab-partners {
  display: grid;
  gap: 14px;
  margin: 4px 0 0;
}

.page-about .ab-partners__item {
  padding: 20px;
  border: 1px solid var(--line);
  background: linear-gradient(160deg, var(--deep-green), var(--ink-green));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .ab-partners__item h3 {
  margin: 0 0 8px;
  font-size: var(--step1);
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--neon-cyan);
}

.page-about .ab-partners__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.74;
  color: rgba(242, 247, 245, .76);
}

/* ---------- 纸张引用块 ---------- */
.page-about .ab-quoteWrap {
  position: relative;
  margin: 4px 0 34px;
}

.page-about .ab-quoteWrap::before {
  content: "";
  position: absolute;
  inset: 0;
  transform: translate(12px, 12px);
  border: 1px solid var(--line);
  pointer-events: none;
}

.page-about .ab-quote {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 26px 24px 22px;
  color: var(--charcoal);
  background: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .ab-quote p {
  max-width: 44ch;
  margin: 0 0 12px;
  font-size: var(--step1);
  line-height: 1.74;
  color: var(--charcoal);
}

.page-about .ab-quote p:last-child {
  margin-bottom: 0;
}

/* ---------- 收束入口 ---------- */
.page-about .ab-next {
  margin-top: 26px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .ab-next__label {
  margin: 0 0 12px;
  font-size: var(--step-1);
  letter-spacing: .16em;
  color: var(--sage);
}

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

.page-about .ab-next__links a {
  display: inline-block;
  padding: 10px 18px 10px 16px;
  font-size: 15px;
  color: var(--paper);
  text-decoration: none;
  background: var(--deep-green);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
  transition: color .18s ease, background-color .18s ease, border-color .18s ease;
}

.page-about .ab-next__links a:hover {
  color: var(--ink-green);
  background: var(--neon-cyan);
  border-color: var(--neon-cyan);
}

.page-about .ab-next__links a:focus-visible {
  outline: 2px solid var(--neon-cyan);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .ab-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .ab-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 780px) {
  .page-about .ab-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .ab-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, .78fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .ab-split .ab-fig--cut {
    margin-top: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 34px 0 68px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) 268px;
    gap: 56px;
    align-items: end;
  }

  .page-about .about-hero__lede {
    font-size: 18px;
  }
}

@media (min-width: 1040px) {
  .page-about .about-body {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: var(--ab-gap);
    align-items: start;
  }

  .page-about .about-rail {
    top: 32px;
    padding: 0;
    background: transparent;
    border-bottom: 0;
  }

  .page-about .about-rail__cap {
    display: block;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
  }

  .page-about .ab-sec {
    padding-top: 56px;
    margin-top: 56px;
  }

  .page-about .ab-sec:first-child {
    padding-top: 0;
    margin-top: 0;
    border-top: 0;
  }

  .page-about .ab-quote {
    padding: 34px 36px 30px;
  }
}

@media (min-width: 1240px) {
  .page-about .ab-fig--wide {
    margin-right: calc(-1 * var(--ab-gap));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .crumbs__link,
  .page-about .ab-next__links a,
  .page-about .ab-tl__mark::before,
  .page-about .ab-tl__mark::after {
    transition: none;
  }
}