.page-about {
  --about-rail: 148px;
  --about-measure: 34em;
  --about-faint: rgba(242, 239, 231, 0.68);
  --about-soft: rgba(242, 239, 231, 0.6);
  --about-hair: rgba(140, 154, 163, 0.22);
  position: relative;
  overflow-x: hidden;
  color: var(--paper);
  background: var(--ink-900);
  padding-bottom: clamp(56px, 9vw, 132px);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  margin-top: clamp(20px, 3vw, 36px);
}
.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--stone);
}
.page-about .breadcrumb__link {
  color: var(--stone);
  text-decoration: none;
  transition: color 0.18s ease;
}
.page-about .breadcrumb__link:hover {
  color: var(--amber);
}
.page-about .breadcrumb__sep {
  color: rgba(140, 154, 163, 0.5);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(38px, 6.5vw, 92px) 0 clamp(30px, 4.6vw, 58px);
  border-bottom: 1px solid var(--about-hair);
}
.page-about .about-hero__kicker {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 0 0 clamp(20px, 3vw, 34px);
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--stone);
}
.page-about .about-hero__kicker::before {
  content: "";
  width: 34px;
  height: 1px;
  background: var(--amber);
}
.page-about .about-hero__title {
  margin: 0;
  max-width: 15em;
  font-size: clamp(32px, 6vw, 78px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
}
.page-about .about-hero__title em {
  font-style: normal;
  color: var(--amber);
}
.page-about .about-hero__lede {
  margin: clamp(20px, 3vw, 32px) 0 0;
  max-width: 34em;
  font-size: clamp(15px, 1.2vw, 18px);
  line-height: 1.75;
  color: var(--about-faint);
}
.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(26px, 5vw, 72px);
  margin: clamp(32px, 5vw, 56px) 0 0;
  padding: clamp(20px, 2.8vw, 32px) 0 0;
  list-style: none;
  border-top: 1px solid var(--about-hair);
}
.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 84px;
}
.page-about .about-hero__stat-num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 42px);
  font-weight: 600;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}
.page-about .about-hero__stat-label {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--stone);
}

/* ---------- 纵向章节骨架 ---------- */
.page-about .about-chapter {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  padding: clamp(42px, 6vw, 90px) 0;
  border-bottom: 1px solid var(--about-hair);
}
.page-about .about-chapter__aside {
  display: flex;
  align-items: flex-start;
}
.page-about .about-chapter__aside .vertical-note {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  white-space: nowrap;
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--stone);
}
.page-about .about-chapter__title {
  margin: 0 0 clamp(18px, 2.4vw, 28px);
  max-width: 20em;
  font-size: clamp(25px, 3.6vw, 44px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.02em;
}
.page-about .about-chapter__text {
  margin: 0 0 18px;
  max-width: var(--about-measure);
  font-size: clamp(15px, 1.1vw, 17px);
  line-height: 1.75;
  color: var(--about-faint);
}
.page-about .about-chapter__text strong {
  color: var(--paper);
  font-weight: 600;
}

/* ---------- 三块支柱 ---------- */
.page-about .about-pillars {
  display: grid;
  gap: 1px;
  margin-top: clamp(26px, 4vw, 42px);
  background: var(--about-hair);
  border-top: 1px solid var(--about-hair);
  border-bottom: 1px solid var(--about-hair);
}
.page-about .about-pillar {
  background: var(--ink-900);
  padding: clamp(20px, 2.6vw, 30px) clamp(18px, 2.4vw, 26px);
}
.page-about .about-pillar__label {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--amber);
}
.page-about .about-pillar__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--about-faint);
}

/* ---------- 历程时间线 ---------- */
.page-about .about-timeline {
  margin: clamp(24px, 3.6vw, 40px) 0 0;
}
.page-about .about-eras {
  margin-top: clamp(26px, 3.8vw, 42px);
  border-top: 1px solid var(--about-hair);
}
.page-about .about-era {
  border-bottom: 1px solid var(--about-hair);
}
.page-about .about-era__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 16px;
  padding: clamp(16px, 2.2vw, 24px) 0;
  cursor: pointer;
  list-style: none;
}
.page-about .about-era__head::-webkit-details-marker {
  display: none;
}
.page-about .about-era__head::marker {
  content: "";
}
.page-about .about-era__index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--clay);
  min-width: 3em;
}
.page-about .about-era__name {
  font-size: clamp(16px, 1.8vw, 21px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--paper);
  transition: color 0.18s ease;
}
.page-about .about-era[open] .about-era__name {
  color: var(--amber);
}
.page-about .about-era__chev {
  position: relative;
  width: 14px;
  height: 14px;
  flex: none;
}
.page-about .about-era__chev::before,
.page-about .about-era__chev::after {
  content: "";
  position: absolute;
  background: var(--stone);
  transition: opacity 0.18s ease, background-color 0.18s ease;
}
.page-about .about-era__chev::before {
  left: 0;
  right: 0;
  top: 6px;
  height: 1px;
}
.page-about .about-era__chev::after {
  top: 0;
  bottom: 0;
  left: 6px;
  width: 1px;
}
.page-about .about-era[open] .about-era__chev::after {
  opacity: 0;
}
.page-about .about-era[open] .about-era__chev::before {
  background: var(--amber);
}
.page-about .about-era__body {
  max-width: var(--about-measure);
  padding: 0 0 clamp(20px, 3vw, 30px);
}
.page-about .about-era__body p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-faint);
}
.page-about .about-era__points {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-era__points li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.65;
  color: var(--about-soft);
}
.page-about .about-era__points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 1px;
  background: var(--amber);
}

/* ---------- 团队 ---------- */
.page-about .about-team-figure {
  margin: clamp(24px, 3.6vw, 40px) 0 0;
}
.page-about .about-team {
  display: grid;
  gap: 1px;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--about-hair);
}
.page-about .about-team__item {
  background: var(--ink-900);
  padding: clamp(20px, 2.6vw, 28px) clamp(18px, 2.4vw, 26px);
}
.page-about .about-team__role {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--mint);
}
.page-about .about-team__name {
  display: block;
  margin-bottom: 12px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}
.page-about .about-team__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--about-faint);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  margin-top: clamp(24px, 3.4vw, 38px);
}
.page-about .about-partners__figure {
  margin: 0;
  max-width: 460px;
}
.page-about .about-partners__list {
  display: grid;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-hair);
}
.page-about .about-partner {
  position: relative;
  padding: clamp(16px, 2.2vw, 24px) 0 clamp(16px, 2.2vw, 24px) 18px;
  border-bottom: 1px solid var(--about-hair);
}
.page-about .about-partner::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--amber);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.18s ease;
}
.page-about .about-partner:hover::before {
  transform: scaleY(1);
}
.page-about .about-partner__tag {
  display: inline-block;
  margin-bottom: 10px;
}
.page-about .about-partner__text {
  margin: 0;
  max-width: 34em;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--about-faint);
}

/* ---------- 四条原则 ---------- */
.page-about .about-principles {
  margin-top: clamp(24px, 3.4vw, 38px);
  border-top: 1px solid var(--about-hair);
}
.page-about .about-principle {
  border-bottom: 1px solid var(--about-hair);
}
.page-about .about-principle__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 18px;
  padding: clamp(18px, 2.4vw, 26px) 0;
  cursor: pointer;
  list-style: none;
}
.page-about .about-principle__head::-webkit-details-marker {
  display: none;
}
.page-about .about-principle__head::marker {
  content: "";
}
.page-about .about-principle__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--clay);
}
.page-about .about-principle__name {
  font-size: clamp(17px, 2vw, 24px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--paper);
  transition: color 0.18s ease;
}
.page-about .about-principle[open] .about-principle__name {
  color: var(--mint);
}
.page-about .about-principle__chev {
  position: relative;
  width: 14px;
  height: 14px;
  flex: none;
}
.page-about .about-principle__chev::before,
.page-about .about-principle__chev::after {
  content: "";
  position: absolute;
  background: var(--stone);
  transition: opacity 0.18s ease, background-color 0.18s ease;
}
.page-about .about-principle__chev::before {
  left: 0;
  right: 0;
  top: 6px;
  height: 1px;
}
.page-about .about-principle__chev::after {
  top: 0;
  bottom: 0;
  left: 6px;
  width: 1px;
}
.page-about .about-principle[open] .about-principle__chev::after {
  opacity: 0;
}
.page-about .about-principle[open] .about-principle__chev::before {
  background: var(--mint);
}
.page-about .about-principle__scene {
  margin: 0;
  max-width: var(--about-measure);
  padding: 0 0 clamp(18px, 2.4vw, 26px);
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-faint);
}

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 16px;
  margin-top: clamp(48px, 7vw, 96px);
  padding: clamp(30px, 4.6vw, 58px) clamp(22px, 3.6vw, 54px);
  background: var(--ink-800);
  border: 1px solid var(--about-hair);
}
.page-about .about-cta__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--coral);
}
.page-about .about-cta__title {
  margin: 0;
  max-width: 18em;
  font-size: clamp(24px, 3.2vw, 38px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
}
.page-about .about-cta__text {
  margin: 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-faint);
}
.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-top: 6px;
}
.page-about .about-cta__note {
  margin: 4px 0 0;
  max-width: 46em;
  font-size: 13px;
  line-height: 1.75;
  color: var(--stone);
}
.page-about .about-cta__note .mono {
  color: var(--paper);
}

/* ---------- 媒体容器 ---------- */
.page-about .media-frame {
  overflow: hidden;
  border: 1px solid var(--about-hair);
}
.page-about .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .about-pillars {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-rail: 168px;
  }
  .page-about .about-chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 0 clamp(32px, 6vw, 80px);
  }
  .page-about .about-chapter__aside {
    position: sticky;
    top: 108px;
    align-self: start;
    padding-top: 8px;
  }
  .page-about .about-chapter__aside .vertical-note {
    font-size: 12px;
  }
}

@media (min-width: 920px) {
  .page-about .about-partners {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    align-items: start;
  }
  .page-about .about-partners__figure {
    max-width: none;
  }
}

@media (min-width: 1060px) {
  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
    column-gap: clamp(32px, 5vw, 72px);
  }
  .page-about .about-cta__kicker {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  .page-about .about-hero__stats {
    gap: 22px;
  }
  .page-about .about-hero__stat-num {
    font-size: 28px;
  }
  .page-about .about-era__head,
  .page-about .about-principle__head {
    gap: 12px;
  }
  .page-about .about-partner {
    padding-left: 14px;
  }
  .page-about .about-cta__actions {
    gap: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-era__chev::before,
  .page-about .about-era__chev::after,
  .page-about .about-principle__chev::before,
  .page-about .about-principle__chev::after,
  .page-about .about-partner::before,
  .page-about .about-era__name,
  .page-about .about-principle__name {
    transition: none;
  }
  .page-about .about-partner::before {
    transform: scaleY(1);
    opacity: 0;
  }
  .page-about .about-partner:hover::before {
    opacity: 1;
  }
}