.page-about {
  --about-gutter: clamp(28px, 4vw, 56px);
  --about-idx-w: 208px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding-top: 18px;
  font-size: 13px;
  color: var(--mist);
}
.page-about .breadcrumbs a {
  color: var(--mist);
  text-decoration: none;
}
.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--cyan);
}
.page-about .breadcrumbs__sep {
  margin: 0 8px;
  color: var(--line-strong);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(28px, 4vw, 52px) 0 0;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(115% 95% at 86% -18%, rgba(26, 20, 64, .95), transparent 62%),
    linear-gradient(180deg, var(--ink-2), var(--ink));
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -90px;
  right: -110px;
  width: clamp(220px, 30vw, 400px);
  height: clamp(220px, 30vw, 400px);
  background: linear-gradient(140deg, rgba(47, 243, 224, .16), transparent 68%);
  transform: rotate(26deg);
  pointer-events: none;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: 900px;
}
.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 5.6vw, 66px);
  line-height: 1.08;
  letter-spacing: -0.025em;
  color: var(--paper);
  text-wrap: balance;
}
.page-about .about-hero__lede {
  margin: clamp(16px, 2vw, 24px) 0 0;
  max-width: 68ch;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.75;
  color: var(--mist);
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 34px);
}

/* ---------- 首屏数据条 ---------- */
.page-about .about-facts {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 20px;
  margin: clamp(30px, 4vw, 52px) 0 0;
  padding: clamp(20px, 3vw, 30px) 0 clamp(24px, 3vw, 34px);
  list-style: none;
  border-top: 1px solid var(--line);
}
.page-about .about-facts__num {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 3.6vw, 44px);
  line-height: 1;
  letter-spacing: 0.03em;
  color: var(--cyan);
}
.page-about .about-facts__label {
  display: block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--mist);
}
@media (min-width: 840px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .about-facts > li {
    padding: 0 26px;
    border-left: 1px solid var(--line);
  }
  .page-about .about-facts > li:first-child {
    padding-left: 0;
    border-left: 0;
  }
}

/* ---------- 主体两列 ---------- */
.page-about .about-body {
  padding: clamp(36px, 5vw, 72px) 0 clamp(48px, 6vw, 88px);
}
.page-about .about-body__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 3vw, 40px);
}

/* ---------- 章节索引 ---------- */
.page-about .chap-index__title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--mist);
}
.page-about .chap-index__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .chap-index__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  flex: 0 0 auto;
  padding: 8px 12px;
  border: 1px solid var(--line);
  background: var(--ink-2);
  color: var(--mist);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color .2s var(--ease), color .2s var(--ease), background .2s var(--ease);
}
.page-about .chap-index__no {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--term);
}
.page-about .chap-index__link:hover,
.page-about .chap-index__link:focus-visible {
  border-color: var(--cyan);
  color: var(--paper);
  background: var(--ink-3);
  outline: none;
}
@media (min-width: 1000px) {
  .page-about .about-body__grid {
    grid-template-columns: var(--about-idx-w) minmax(0, 1fr);
    gap: clamp(36px, 4vw, 76px);
  }
  .page-about .chap-index {
    position: sticky;
    top: calc(var(--head-h) + 28px);
    align-self: start;
  }
  .page-about .chap-index__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .chap-index__link {
    border: 0;
    border-left: 2px solid var(--line);
    background: transparent;
    padding: 7px 0 7px 14px;
  }
  .page-about .chap-index__link:hover,
  .page-about .chap-index__link:focus-visible {
    border-left-color: var(--cyan);
    background: transparent;
  }
}

/* ---------- 章节 ---------- */
.page-about .chap-stack {
  display: grid;
  gap: clamp(34px, 4vw, 60px);
  min-width: 0;
}
.page-about .chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  padding-top: clamp(22px, 3vw, 34px);
  border-top: 1px solid var(--line);
  min-width: 0;
}
.page-about .chapter:target {
  border-top-color: var(--cyan);
}
.page-about .chapter__num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(38px, 7.5vw, 68px);
  line-height: 0.88;
  letter-spacing: -0.03em;
  color: rgba(47, 243, 224, .18);
  -webkit-text-stroke: 1.4px rgba(47, 243, 224, .52);
}
.page-about .chapter__body {
  min-width: 0;
}
@media (min-width: 760px) {
  .page-about .chapter {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: clamp(20px, 3vw, 40px);
  }
}
@media (min-width: 1200px) {
  .page-about .chapter {
    grid-template-columns: 118px minmax(0, 1fr);
  }
  .page-about .chapter__num {
    font-size: clamp(64px, 5vw, 84px);
  }
}

.page-about .chapter__title {
  margin: 0 0 clamp(14px, 2vw, 20px);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3vw, 36px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--paper);
  text-wrap: balance;
}
.page-about .chapter__intro {
  margin: 0 0 clamp(20px, 2.6vw, 28px);
  color: var(--mist);
}
.page-about .chapter__prose p {
  margin: 0 0 1em;
  color: var(--paper);
  font-size: clamp(15px, 1.2vw, 16.5px);
  line-height: 1.78;
}
.page-about .chapter__prose a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 243, 224, .4);
}
.page-about .chapter__prose a:hover,
.page-about .chapter__prose a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .chapter__cols {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
  grid-template-columns: minmax(0, 1fr);
}
@media (min-width: 900px) {
  .page-about .chapter__cols {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }
}

/* ---------- 图片 ---------- */
.page-about .media {
  margin: 0;
  overflow: hidden;
}
.page-about .media img {
  position: static;
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}
.page-about .chapter__wide {
  margin: clamp(22px, 3vw, 34px) 0 0;
}
.page-about .media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 数据摘要行 ---------- */
.page-about .sum-line {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line-strong);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.05em;
  color: var(--term);
}
.page-about .sum-line span {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.page-about .sum-line span + span::before {
  content: "";
  width: 5px;
  height: 5px;
  background: var(--orange);
  transform: rotate(45deg);
}

/* ---------- 时间线 ---------- */
.page-about .tl {
  position: relative;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0 0 0 30px;
  list-style: none;
}
.page-about .tl::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), rgba(47, 243, 224, .06));
}
.page-about .tl__item + .tl__item {
  margin-top: 18px;
}
.page-about .tl__node {
  position: relative;
  border: 1px solid var(--line);
  background: var(--ink-2);
  padding: 16px 18px;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.page-about .tl__node::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 22px;
  width: 14px;
  height: 14px;
  background: var(--ink);
  border: 2px solid var(--line-strong);
  transition: background .2s var(--ease), border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.page-about .tl__node:hover {
  border-color: rgba(47, 243, 224, .5);
}
.page-about .tl__node[open] {
  border-color: rgba(47, 243, 224, .45);
  background: var(--ink-3);
}
.page-about .tl__node[open]::before {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 243, 224, .14);
}
.page-about .tl__sum {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  cursor: pointer;
  list-style: none;
}
.page-about .tl__sum::-webkit-details-marker {
  display: none;
}
.page-about .tl__sum:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}
.page-about .tl__season {
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--orange);
  border: 1px solid rgba(255, 122, 26, .45);
  padding: 2px 8px;
}
.page-about .tl__head {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(17px, 1.8vw, 21px);
  letter-spacing: -0.01em;
  color: var(--paper);
}
.page-about .tl__desc {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
  max-width: 68ch;
}

/* ---------- 团队卡片 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: clamp(20px, 3vw, 28px);
}
@media (min-width: 780px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}
.page-about .team-card {
  position: relative;
  min-height: 220px;
  perspective: 1100px;
  outline: none;
}
.page-about .team-card__inner {
  position: absolute;
  inset: 0;
  transform-style: preserve-3d;
  transition: transform .52s var(--ease);
}
.page-about .team-card:hover .team-card__inner,
.page-about .team-card:focus-within .team-card__inner,
.page-about .team-card:focus .team-card__inner {
  transform: rotateY(180deg);
}
.page-about .team-card__face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  border: 1px solid var(--line);
  background: var(--ink-2);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}
.page-about .team-card__face--front {
  justify-content: space-between;
  border-left: 3px solid var(--cyan);
}
.page-about .team-card__face--back {
  transform: rotateY(180deg);
  border-color: rgba(47, 243, 224, .42);
  background: linear-gradient(160deg, var(--indigo), var(--ink-2) 78%);
}
.page-about .team-card__num {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--term);
}
.page-about .team-card__role {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 2.2vw, 26px);
  letter-spacing: -0.01em;
  color: var(--paper);
}
.page-about .team-card__hint {
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--mist);
}
.page-about .team-card__face--back p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--paper);
}
@media (hover: none) {
  .page-about .team-card {
    min-height: 0;
    perspective: none;
  }
  .page-about .team-card__inner {
    position: static;
    inset: auto;
    transform: none;
    transform-style: flat;
    display: grid;
    gap: 12px;
  }
  .page-about .team-card__face {
    position: static;
    inset: auto;
    transform: none;
    backface-visibility: visible;
    -webkit-backface-visibility: visible;
  }
  .page-about .team-card__face--back {
    transform: none;
  }
  .page-about .team-card__hint {
    display: none;
  }
}

/* ---------- 协作生态引框 ---------- */
.page-about .collab-quote {
  position: relative;
  margin-top: clamp(18px, 2.4vw, 26px);
  padding: clamp(24px, 3.6vw, 42px);
  border: 1px solid rgba(47, 243, 224, .26);
  border-left: 4px solid var(--gold);
  background: linear-gradient(160deg, var(--indigo), rgba(26, 20, 64, .34) 72%);
}
.page-about .collab-quote::before,
.page-about .collab-quote::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border: 1px solid rgba(233, 185, 73, .55);
  pointer-events: none;
}
.page-about .collab-quote::before {
  top: 8px;
  right: 8px;
  border-left: 0;
  border-bottom: 0;
}
.page-about .collab-quote::after {
  bottom: 8px;
  right: 8px;
  border-left: 0;
  border-top: 0;
}
.page-about .collab-quote p {
  margin: 0 0 1em;
  max-width: 68ch;
  font-size: clamp(15px, 1.2vw, 16.5px);
  line-height: 1.78;
  color: var(--paper);
}
.page-about .collab-quote p:last-child {
  margin-bottom: 0;
}
.page-about .collab-quote a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(233, 185, 73, .5);
}
.page-about .collab-quote a:hover,
.page-about .collab-quote a:focus-visible {
  border-bottom-color: var(--gold);
}

/* ---------- 收口 CTA ---------- */
.page-about .about-cta {
  border-top: 1px solid var(--line);
  background:
    radial-gradient(90% 130% at 12% 0%, rgba(11, 46, 44, .9), transparent 62%),
    var(--ink-2);
  padding: clamp(38px, 5vw, 70px) 0;
}
.page-about .about-cta__inner {
  max-width: 760px;
}
.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.2vw, 38px);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--paper);
}
.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--mist);
}
.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 30px);
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .team-card__inner,
  .page-about .tl__node,
  .page-about .tl__node::before,
  .page-about .chap-index__link {
    transition: none;
  }
  .page-about .team-card:hover .team-card__inner,
  .page-about .team-card:focus .team-card__inner,
  .page-about .team-card:focus-within .team-card__inner {
    transform: none;
  }
  .page-about .team-card:hover .team-card__face--front {
    opacity: 0;
  }
  .page-about .team-card__face--back {
    transform: none;
    opacity: 0;
    transition: opacity .2s linear;
  }
  .page-about .team-card:hover .team-card__face--back,
  .page-about .team-card:focus .team-card__face--back,
  .page-about .team-card:focus-within .team-card__face--back {
    opacity: 1;
  }
}
<<<END>>>