.page-about {
  --about-soft: #B7C0CE;
  --about-rail: 236px;
  --about-gap: 64px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 40px 0 40px;
  background: linear-gradient(180deg, rgba(20, 22, 26, .92), rgba(10, 11, 13, 0) 82%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -34%;
  right: -20%;
  width: 64%;
  height: 130%;
  transform: rotate(-4deg);
  background: linear-gradient(112deg, rgba(242, 193, 78, .12), rgba(53, 214, 226, .07) 48%, transparent 74%);
  pointer-events: none;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  left: -6%;
  right: -6%;
  bottom: 0;
  height: 5px;
  transform: skewY(-1.2deg);
  opacity: .45;
  background: linear-gradient(90deg, transparent, var(--amber) 28%, var(--cyan) 72%, transparent);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .about-hero__kicker {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--display);
  font-weight: 900;
  font-size: clamp(32px, 8.2vw, 66px);
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--white);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 40ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-soft);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px 30px;
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-hero__fv {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 21px;
  font-weight: 600;
  color: var(--gold);
  line-height: 1;
}

.page-about .about-hero__fk {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mist);
}

.page-about .about-hero__fig {
  margin: 0;
  position: relative;
}

.page-about .about-hero__fig img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-left: 2px solid var(--gold);
  background: var(--ink-2);
  object-fit: cover;
}

.page-about .about-hero__fig figcaption {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  padding: 16px 0 72px;
}

.page-about .about-rail {
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.page-about .about-rail__title {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist);
}

.page-about .about-toc {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px 16px;
}

.page-about .about-toc__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-toc__num {
  color: var(--amber);
}

.page-about .about-toc__link:hover {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

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

/* ---------- 章节 ---------- */
.page-about .about-sec {
  position: relative;
  padding-top: 44px;
}

.page-about .about-sec + .about-sec {
  margin-top: 48px;
}

.page-about .about-sec::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 24px;
  height: 1px;
  background: var(--line);
}

.page-about .about-sec__index {
  margin: 0 0 2px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .about-sec__num {
  display: block;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(56px, 13vw, 104px);
  line-height: .9;
  letter-spacing: -.02em;
  color: var(--gold);
  opacity: .36;
  transition: opacity 220ms var(--ease);
}

.page-about .about-sec__num:hover {
  opacity: .88;
  -webkit-text-stroke: 1px var(--gold);
}

.page-about .about-sec__title {
  margin: 12px 0 0;
  font-family: var(--display);
  font-weight: 900;
  font-size: clamp(25px, 5.4vw, 42px);
  line-height: 1.16;
  letter-spacing: -.02em;
  color: var(--white);
}

.page-about .about-sec__body {
  margin-top: 26px;
  max-width: 70ch;
}

.page-about .about-sec__body > p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-soft);
}

.page-about .about-sec__body > p:last-child {
  margin-bottom: 0;
}

/* ---------- 栏目行 ---------- */
.page-about .about-rows {
  display: grid;
  gap: 1px;
  margin: 26px 0 26px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-row {
  padding: 20px 20px 20px 20px;
  background: var(--ink-2);
  border-left: 2px solid transparent;
  transition: border-left-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-row:hover {
  border-left-color: var(--gold);
  background: var(--slab);
}

.page-about .about-row__k {
  margin: 0 0 7px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--amber);
}

.page-about .about-row__t {
  margin: 0 0 8px;
  font-family: var(--display);
  font-weight: 900;
  font-size: 17px;
  letter-spacing: -.01em;
  color: var(--white);
}

.page-about .about-row__d {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 图片 ---------- */
.page-about .about-media {
  margin: 0;
}

.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  background: var(--ink-2);
  object-fit: cover;
}

.page-about .about-media figcaption {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .06em;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .about-media--wide {
  margin: 30px 0 4px;
  max-width: 900px;
}

/* ---------- 规模 ---------- */
.page-about .about-scale {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-figures {
  list-style: none;
  margin: 26px 0 24px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-fig {
  background: var(--ink-2);
  padding: 18px 16px;
}

.page-about .about-fig__v {
  display: block;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 3.2vw, 28px);
  font-weight: 600;
  line-height: 1.15;
  color: var(--gold);
}

.page-about .about-fig__k {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--mist);
}

/* ---------- 发展历程 ---------- */
.page-about .about-phases {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-phases::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), var(--cyan) 52%, var(--line));
}

.page-about .phase {
  position: relative;
  padding: 0 0 30px 38px;
  outline: none;
}

.page-about .phase:last-child {
  padding-bottom: 0;
}

.page-about .phase__dot {
  position: absolute;
  left: 0;
  top: 5px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--gold);
  transition: box-shadow var(--dur) var(--ease);
}

.page-about .phase__dot::after {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 50%;
  background: var(--gold);
}

.page-about .phase:hover .phase__dot,
.page-about .phase:focus .phase__dot {
  box-shadow: 0 0 0 5px rgba(242, 193, 78, .16);
}

.page-about .phase:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .phase__era {
  margin: 0;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .phase__title {
  margin: 7px 0 8px;
  font-family: var(--display);
  font-weight: 900;
  font-size: 18px;
  letter-spacing: -.01em;
  color: var(--white);
}

.page-about .phase__note {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 26px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-team__item {
  padding: 22px 20px 24px;
  background: var(--ink-2);
  border-top: 2px solid var(--line);
  transition: background-color var(--dur) var(--ease), border-top-color var(--dur) var(--ease);
}

.page-about .about-team__item:nth-child(1) {
  border-top-color: var(--gold);
}

.page-about .about-team__item:nth-child(2) {
  border-top-color: var(--cyan);
}

.page-about .about-team__item:nth-child(3) {
  border-top-color: var(--rose);
}

.page-about .about-team__item:hover {
  background: var(--slab);
}

.page-about .about-team__k {
  margin: 0 0 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist);
}

.page-about .about-team__t {
  margin: 0 0 10px;
  font-family: var(--display);
  font-weight: 900;
  font-size: 17px;
  line-height: 1.35;
  color: var(--white);
}

.page-about .about-team__d {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 合作 ---------- */
.page-about .about-partners {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-partners__side {
  padding: 22px 20px;
  background: var(--ink-2);
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan);
}

.page-about .about-partners__n {
  margin: 0;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 34px;
  font-weight: 600;
  line-height: 1;
  color: var(--gold);
}

.page-about .about-partners__l {
  margin: 6px 0 18px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--mist);
}

.page-about .about-partners__l:last-of-type {
  margin-bottom: 0;
}

.page-about .about-partners__note {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 26px 0 0;
}

.page-about .about-cta__link {
  display: inline-flex;
  align-items: center;
  padding: 11px 20px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--white);
  background: transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-cta__link:hover {
  border-color: var(--gold);
  color: var(--gold);
}

.page-about .about-cta__link--gold {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}

.page-about .about-cta__link--gold:hover {
  background: var(--amber);
  border-color: var(--amber);
  color: var(--ink);
}

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

.page-about .about-back {
  margin: 24px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-back a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: border-color var(--dur) var(--ease);
}

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

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

/* ---------- 宽屏 ---------- */
@media (min-width: 720px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 68px 0 56px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    gap: 48px 56px;
    align-items: end;
  }

  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    padding: 40px 0 120px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--bar-h-sm, 48px) + 28px);
    align-self: start;
    border-top: none;
    border-left: 1px solid var(--line);
    padding: 0 0 0 20px;
  }

  .page-about .about-toc {
    grid-template-columns: 1fr;
    gap: 0;
  }

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

  .page-about .about-sec + .about-sec {
    margin-top: 64px;
  }

  .page-about .about-scale {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, .75fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-partners {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .phase__note {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 280ms var(--ease), opacity 220ms var(--ease);
  }

  .page-about .phase:hover .phase__note,
  .page-about .phase:focus .phase__note {
    max-height: 180px;
    opacity: 1;
  }
}

@media (min-width: 1180px) {
  .page-about {
    --about-rail: 268px;
    --about-gap: 80px;
  }
}