.page-about {
  --about-chapter-pad: clamp(56px, 8vw, 112px);
  --about-mark-w: 96px;
}

.page-about .about-crumb {
  padding-top: 22px;
  padding-bottom: 8px;
}

.page-about .about-crumb .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--concrete);
}

.page-about .about-crumb .breadcrumb a {
  color: var(--concrete);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .about-crumb .breadcrumb a:hover {
  color: var(--warm);
  border-bottom-color: var(--signal);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(30px, 5vw, 64px) 0 clamp(34px, 5vw, 72px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, var(--signal) 0%, var(--signal) 18%, var(--line) 18%, var(--line) 100%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(28px, 4vw, 56px);
  align-items: end;
}

.page-about .about-hero__text {
  min-width: 0;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(34px, 7.4vw, 76px);
  line-height: 1.02;
  letter-spacing: -.035em;
  margin: 14px 0 0;
  color: var(--warm);
}

.page-about .about-hero__lead {
  margin: clamp(18px, 2.4vw, 28px) 0 0;
  max-width: 46ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--concrete);
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  margin: 26px 0 0;
  padding: 16px 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--concrete);
}

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

.page-about .about-hero__facts .data-text {
  font-family: var(--font-mono);
  font-size: 18px;
  letter-spacing: .02em;
  color: var(--warm);
}

.page-about .about-hero__facts li:first-child .data-text {
  color: var(--signal);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 46px;
  padding: 0 22px;
  border: 0;
  border-radius: 0;
  background: var(--signal);
  color: var(--warm);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: .04em;
  text-decoration: none;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  transition: background .18s var(--ease), transform .18s var(--ease);
}

.page-about .about-btn:hover {
  background: var(--signal-dark);
  transform: translateY(-1px);
}

.page-about .about-btn .btn-arrow {
  display: inline-block;
  transition: transform .2s var(--ease);
}

.page-about .about-btn:hover .btn-arrow {
  transform: translateX(3px);
}

.page-about .about-btn-ghost {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 0 20px;
  border: 1px solid var(--line-strong);
  background: transparent;
  color: var(--warm);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: .04em;
  text-decoration: none;
  border-radius: 0;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}

.page-about .about-btn-ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .about-hero__media {
  min-width: 0;
}

.page-about .about-hero__figure {
  position: relative;
  border: 1px solid var(--line-strong);
  background: linear-gradient(150deg, var(--stand) 0%, var(--night) 62%);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-hero__figure .media__caption {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--concrete);
}

/* ---------- 章节索引 ---------- */
.page-about .about-chapters {
  position: sticky;
  top: var(--bar-h);
  z-index: 5;
  background: rgba(10, 18, 38, .92);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(6px);
}

.page-about .about-chapters__inner {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  padding-top: 10px;
  padding-bottom: 10px;
  scrollbar-width: none;
}

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

.page-about .about-chapters a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
  min-height: 40px;
  padding: 0 14px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--concrete);
  text-decoration: none;
  border: 1px solid transparent;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
  transition: color .18s var(--ease), border-color .18s var(--ease), background .18s var(--ease);
}

.page-about .about-chapters a:hover {
  color: var(--warm);
  border-color: var(--line-strong);
  background: rgba(20, 33, 61, .8);
}

.page-about .about-chapters__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--signal);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  position: relative;
  padding: var(--about-chapter-pad) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-chapter::after {
  content: "";
  position: absolute;
  right: 0;
  top: 0;
  width: 46%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong));
  transform: skewY(-1.2deg);
  transform-origin: right top;
  pointer-events: none;
}

.page-about .about-chapter__grid {
  display: grid;
  gap: 22px;
}

.page-about .about-chapter__mark {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-chapter__num {
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(52px, 12vw, 92px);
  line-height: .82;
  letter-spacing: -.05em;
  color: transparent;
  -webkit-text-stroke: 1px var(--line-strong);
}

.page-about .about-chapter__mark .section-index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--concrete);
}

.page-about .about-chapter__body {
  min-width: 0;
}

.page-about .about-chapter__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.14;
  letter-spacing: -.02em;
  margin: 0 0 clamp(18px, 2.4vw, 28px);
  color: var(--warm);
}

.page-about .about-chapter__body .prose {
  max-width: 62ch;
  color: var(--concrete);
  font-size: clamp(15px, 1.4vw, 16px);
  line-height: 1.85;
}

.page-about .about-chapter__body .prose p {
  margin: 0 0 1.1em;
}

.page-about .about-chapter__body .prose p:first-child::first-letter {
  float: left;
  font-family: var(--font-display);
  font-size: 3.1em;
  line-height: .92;
  font-weight: 700;
  padding-right: .12em;
  color: var(--signal);
}

.page-about .about-inline-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-left: 4px;
  color: var(--cyan);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid rgba(50, 230, 208, .38);
}

.page-about .about-inline-link:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 起点卡片 ---------- */
.page-about .about-origin__cards {
  display: grid;
  gap: 1px;
  margin-top: clamp(24px, 3vw, 36px);
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-origin__card {
  padding: 20px 20px 22px;
  background: var(--stand);
  border: 0;
  border-radius: 0;
}

.page-about .about-origin__card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--concrete);
}

.page-about .about-origin__kicker {
  margin-bottom: 8px !important;
  font-family: var(--font-mono);
  font-size: 11px !important;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--signal) !important;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline__lead {
  max-width: 58ch;
  margin: 0 0 clamp(22px, 3vw, 34px);
  color: var(--concrete);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--signal), var(--line-strong) 55%, transparent);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 26px 4px;
}

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

.page-about .about-timeline__dot {
  position: absolute;
  left: -26px;
  top: 6px;
  width: 11px;
  height: 11px;
  background: var(--night);
  border: 1px solid var(--signal);
  transform: rotate(45deg);
}

.page-about .about-timeline__item:first-child .about-timeline__dot {
  background: var(--signal);
}

.page-about .about-timeline__stage {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--cyan);
}

.page-about .about-timeline__heading {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.3;
  color: var(--warm);
}

.page-about .about-timeline__text {
  margin: 0;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--concrete);
}

.page-about .about-timeline__figure {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
}

.page-about .about-timeline__figure .media {
  border: 1px solid var(--line-strong);
  background: linear-gradient(160deg, var(--stand) 0%, var(--night) 70%);
}

.page-about .about-timeline__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-timeline__figure .media__caption {
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--concrete);
}

.page-about .about-timeline__more {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--concrete);
}

/* ---------- 团队 ---------- */
.page-about .about-team__lead {
  max-width: 58ch;
  margin: 0 0 clamp(22px, 3vw, 32px);
  color: var(--concrete);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-team__layout {
  display: grid;
  gap: 22px;
}

.page-about .about-team__grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-role {
  padding: 18px 18px 20px;
  background: var(--night);
  border: 0;
  border-radius: 0;
  transition: background .2s var(--ease);
}

.page-about .about-role:hover,
.page-about .about-role:focus-within {
  background: var(--stand);
}

.page-about .about-role__count {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--amber);
}

.page-about .about-role__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.35;
  color: var(--warm);
}

.page-about .about-role__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--concrete);
}

.page-about .about-role__more {
  max-height: 0;
  margin: 0;
  overflow: hidden;
  font-size: 13px;
  line-height: 1.7;
  color: var(--cyan);
  opacity: 0;
  transition: max-height .26s var(--ease), opacity .26s var(--ease), margin .26s var(--ease);
}

.page-about .about-role:hover .about-role__more,
.page-about .about-role:focus-within .about-role__more {
  max-height: 6em;
  margin-top: 10px;
  opacity: 1;
}

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__figure .media {
  border: 1px solid var(--line-strong);
  background: linear-gradient(150deg, var(--stand) 0%, var(--night) 70%);
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-team__figure .media__caption {
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--concrete);
}

.page-about .about-team__note {
  margin: 20px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--signal);
  font-size: 13px;
  line-height: 1.8;
  color: var(--concrete);
}

/* ---------- 合作 ---------- */
.page-about .about-chapter--partners {
  background: linear-gradient(180deg, rgba(20, 33, 61, .55) 0%, rgba(10, 18, 38, 0) 100%);
}

.page-about .about-partners__lead {
  max-width: 58ch;
  margin: 0 0 clamp(22px, 3vw, 32px);
  color: var(--concrete);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-partners__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

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

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(30px, 5vw, 44px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--warm);
}

.page-about .about-stat:first-child .about-stat__num {
  color: var(--signal);
}

.page-about .about-stat__unit {
  color: var(--cyan);
}

.page-about .about-stat__label {
  margin: 10px 0 6px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--warm);
}

.page-about .about-stat__text {
  margin: 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--concrete);
}

.page-about .about-partners__note {
  margin: 22px 0 0;
  max-width: 62ch;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--concrete);
}

.page-about .about-partners__more {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--concrete);
}

/* ---------- 原则 ---------- */
.page-about .about-principles__lead {
  max-width: 58ch;
  margin: 0 0 clamp(22px, 3vw, 32px);
  color: var(--concrete);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-principles__grid {
  display: grid;
  gap: 12px;
}

.page-about .about-principle {
  position: relative;
  padding: 22px 20px 24px;
  background: var(--stand);
  border: 1px solid var(--line);
  border-radius: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
  transition: border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-principle:hover {
  border-color: var(--signal);
  background: #172648;
}

.page-about .about-principle__no {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--cyan);
}

.page-about .about-principle__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.3;
  color: var(--warm);
}

.page-about .about-principle__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--concrete);
}

.page-about .about-principle--wide {
  background: var(--night);
  border-color: var(--line-strong);
}

.page-about .about-principle__path {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 16px 0 0;
  font-size: 13px;
  color: var(--line-strong);
}

.page-about .about-principle__path a {
  display: inline-block;
  padding: 6px 10px;
  color: var(--warm);
  font-weight: 700;
  text-decoration: none;
  border: 1px solid var(--signal-dark);
  border-radius: 0;
  transition: background .18s var(--ease), color .18s var(--ease);
}

.page-about .about-principle__path a:hover {
  background: var(--signal);
  color: var(--warm);
}

/* ---------- 结尾行动 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 18px;
  margin-top: clamp(26px, 3.4vw, 40px);
  padding: clamp(22px, 3vw, 32px);
  background: linear-gradient(120deg, var(--signal-dark) 0%, var(--signal) 45%, var(--night) 100%);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.page-about .about-cta__text .eyebrow {
  color: rgba(245, 242, 234, .78);
  letter-spacing: .18em;
}

.page-about .about-cta__headline {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 2.8vw, 30px);
  line-height: 1.22;
  letter-spacing: -.02em;
  color: var(--warm);
}

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

.page-about .about-cta .about-btn {
  background: var(--night);
}

.page-about .about-cta .about-btn:hover {
  background: var(--stand);
}

.page-about .about-cta .about-btn-ghost {
  border-color: rgba(245, 242, 234, .55);
  color: var(--warm);
}

.page-about .about-cta .about-btn-ghost:hover {
  border-color: var(--warm);
  color: var(--warm);
  background: rgba(10, 18, 38, .35);
}

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

  .page-about .about-team__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

  .page-about .about-principle--wide {
    grid-column: span 3;
  }

  .page-about .about-cta {
    grid-template-columns: 1.4fr 1fr;
    align-items: center;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-mark-w) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
  }

  .page-about .about-chapter__mark {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: calc(var(--bar-h) + 74px);
    align-self: start;
  }

  .page-about .about-chapter__num {
    font-size: clamp(64px, 6vw, 96px);
  }

  .page-about .about-team__layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: clamp(20px, 2.4vw, 32px);
    align-items: start;
  }

  .page-about .about-team__figure {
    position: sticky;
    top: calc(var(--bar-h) + 74px);
  }

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

  .page-about .about-principle--wide {
    grid-column: span 3;
  }
}

@media (min-width: 1100px) {
  .page-about .about-chapters__inner {
    gap: 8px;
  }

  .page-about .about-team__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-btn,
  .page-about .about-btn .btn-arrow,
  .page-about .about-role,
  .page-about .about-role__more,
  .page-about .about-principle {
    transition: none;
  }

  .page-about .about-btn:hover,
  .page-about .about-btn:hover .btn-arrow {
    transform: none;
  }
}