.page-about {
  --about-cut: 14px;
  --about-dot: 9px;
  background: var(--paper);
  color: var(--ink);
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: 36px 0 52px;
  background: var(--indigo-900);
  color: var(--paper);
}

.page-about .about-hero__figure {
  position: absolute;
  inset: 0;
  z-index: 0;
  margin: 0;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.42;
}

.page-about .about-hero__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(120% 90% at 16% 8%, rgba(46, 74, 133, 0.58), transparent 62%),
    linear-gradient(180deg, rgba(15, 27, 51, 0.58) 0%, rgba(15, 27, 51, 0.9) 66%, var(--indigo-900) 100%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0 0 30px;
  padding: 0;
  list-style: none;
  font-size: 0.8125rem;
  color: rgba(246, 241, 231, 0.62);
}

.page-about .about-hero .breadcrumb__item {
  display: inline-flex;
  align-items: center;
}

.page-about .about-hero .breadcrumb__item + .breadcrumb__item::before {
  content: "／";
  margin-right: 6px;
  color: var(--ochre);
}

.page-about .about-hero .breadcrumb__item a {
  color: rgba(246, 241, 231, 0.88);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb__item a:hover,
.page-about .about-hero .breadcrumb__item a:focus-visible {
  color: var(--paper);
  text-decoration: underline;
}

.page-about .about-hero .eyebrow {
  color: var(--ochre);
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  max-width: 20ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.05rem, 7.2vw, 4.25rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
}

.page-about .about-hero__lead {
  margin: 22px 0 0;
  max-width: 40ch;
  font-size: 1rem;
  line-height: 1.82;
  color: rgba(246, 241, 231, 0.82);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 18px;
  margin: 34px 0 0;
  padding: 20px 0 0;
  list-style: none;
  border-top: 1px solid var(--line-dark);
}

.page-about .about-fact__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .about-fact__label {
  display: block;
  margin-top: 8px;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: rgba(246, 241, 231, 0.58);
}

/* ---------- 通用小节标题 ---------- */
.page-about .about-h2 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.55rem, 4.6vw, 2.5rem);
  line-height: 1.18;
  letter-spacing: -0.02em;
  max-width: 24ch;
}

/* ---------- 编年轴 ---------- */
.page-about .about-era {
  display: grid;
  gap: 34px;
}

.page-about .about-era__rail {
  border-left: 2px solid var(--red);
  padding-left: 14px;
}

.page-about .about-era__rail-title {
  margin: 0 0 12px;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--stone);
}

.page-about .about-era__toc {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-era__toc .toc-link {
  display: inline-block;
  padding: 5px 0;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--stone);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-era__toc .toc-link:hover,
.page-about .about-era__toc .toc-link:focus-visible {
  color: var(--indigo-900);
  border-bottom-color: var(--indigo-500);
}

.page-about .about-era__toc .toc-link.is-active {
  color: var(--red);
  font-weight: 700;
  border-bottom-color: var(--red);
}

.page-about .about-era__intro {
  margin: 16px 0 0;
  max-width: 44ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .about-era__list {
  position: relative;
  margin-top: 30px;
  padding-left: 26px;
  display: grid;
  gap: 18px;
}

.page-about .about-era__list::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 22px;
  width: 1px;
  background: var(--line-light);
}

.page-about .era {
  position: relative;
  padding: 22px 20px 20px;
  background: var(--paper-hi);
  border-left: 3px solid var(--indigo-500);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .era::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 26px;
  width: var(--about-dot);
  height: var(--about-dot);
  background: var(--paper);
  border: 2px solid var(--indigo-500);
  transform: rotate(45deg);
}

.page-about .era__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.14em;
  color: var(--red);
  font-variant-numeric: tabular-nums;
}

.page-about .era__title {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.3125rem;
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--indigo-900);
}

.page-about .era__text {
  margin: 0;
  max-width: 46ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .era__more {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed var(--line-light);
}

.page-about .era__more summary {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  list-style: none;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--indigo-500);
}

.page-about .era__more summary::-webkit-details-marker {
  display: none;
}

.page-about .era__more summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  color: var(--red);
}

.page-about .era__more[open] summary::before {
  content: "–";
}

.page-about .era__more summary:hover,
.page-about .era__more summary:focus-visible {
  color: var(--indigo-900);
}

.page-about .era__more p {
  margin: 10px 0 0;
  max-width: 46ch;
  font-size: 0.875rem;
  line-height: 1.78;
  color: var(--stone);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  align-items: start;
}

.page-about .about-team .about-h2 {
  color: var(--paper);
}

.page-about .about-team .eyebrow {
  color: var(--ochre);
}

.page-about .about-team__lead {
  margin: 16px 0 0;
  max-width: 42ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: rgba(246, 241, 231, 0.76);
}

.page-about .about-roles {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-dark);
}

.page-about .about-role {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-dark);
}

.page-about .about-role__num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  line-height: 1.1;
  color: var(--ochre);
  font-variant-numeric: tabular-nums;
}

.page-about .about-role__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-role__duty {
  margin: 6px 0 0;
  font-size: 0.875rem;
  line-height: 1.72;
  color: rgba(246, 241, 231, 0.6);
}

.page-about .about-role__track {
  display: block;
  margin-top: 12px;
  height: 6px;
  background: rgba(246, 241, 231, 0.14);
}

.page-about .about-role__fill {
  display: block;
  height: 100%;
  width: var(--fill, 0%);
  background: linear-gradient(90deg, var(--teal), var(--mist));
  transition: filter 0.3s var(--ease);
}

.page-about .about-role:hover .about-role__fill,
.page-about .about-role:focus-within .about-role__fill {
  filter: brightness(1.3);
}

.page-about .about-team__figure {
  margin: 32px 0 0;
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-team__figure figcaption {
  margin-top: 12px;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: rgba(246, 241, 231, 0.5);
}

/* ---------- 规模 ---------- */
.page-about .about-scale__intro {
  margin: 16px 0 0;
  max-width: 42ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .about-scale {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px 20px;
  margin-top: 34px;
}

.page-about .about-scale__cell {
  padding-top: 14px;
  border-top: 2px solid var(--indigo-900);
}

.page-about .about-scale__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(2.2rem, 9vw, 3.4rem);
  line-height: 1;
  letter-spacing: -0.05em;
  color: var(--indigo-900);
  font-variant-numeric: tabular-nums;
}

.page-about .about-scale__suffix {
  font-size: 0.44em;
  letter-spacing: 0;
  margin-left: 2px;
  color: var(--red);
}

.page-about .about-scale__unit {
  display: block;
  margin-top: 10px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.page-about .about-scale__note {
  margin: 10px 0 0;
  font-size: 0.875rem;
  line-height: 1.76;
  color: var(--ink);
}

/* ---------- 质量体系 ---------- */
.page-about .about-quality {
  display: grid;
  gap: 30px;
}

.page-about .about-quality__figure {
  margin: 0;
  max-width: 340px;
}

.page-about .about-quality__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 0;
}

.page-about .about-quality__lead {
  margin: 16px 0 0;
  max-width: 44ch;
  font-size: 0.9375rem;
  line-height: 1.82;
  color: var(--ink);
}

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

.page-about .about-quality__item {
  display: grid;
  grid-template-columns: 20px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-top: 1px solid var(--line-light);
}

.page-about .about-quality__item:last-child {
  border-bottom: 1px solid var(--line-light);
}

.page-about .about-quality__check {
  margin-top: 3px;
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1;
  color: var(--teal);
}

.page-about .about-quality__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.0625rem;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--indigo-900);
}

.page-about .about-quality__text {
  margin: 7px 0 0;
  max-width: 48ch;
  font-size: 0.875rem;
  line-height: 1.78;
  color: var(--stone);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners__lead {
  margin: 16px 0 0;
  max-width: 46ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: rgba(246, 241, 231, 0.76);
}

.page-about .about-partners__strip {
  display: flex;
  gap: 10px;
  margin: 28px 0 0;
  padding: 4px 0 16px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-partners__strip > li {
  flex: 0 0 auto;
  scroll-snap-align: start;
}

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

.page-about .about-chip {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 10px 15px;
  border: 1px solid var(--line-dark);
  background: rgba(246, 241, 231, 0.05);
  color: var(--paper);
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  white-space: nowrap;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 10px), calc(100% - 10px) 100%, 0 100%);
}

.page-about .about-chip__dot {
  width: 6px;
  height: 6px;
  background: var(--mist);
  display: inline-block;
}

.page-about .about-partners__note {
  margin: 6px 0 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: rgba(246, 241, 231, 0.58);
}

.page-about .about-partners__note a {
  color: var(--mist);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-partners__note a:hover,
.page-about .about-partners__note a:focus-visible {
  color: var(--paper);
}

/* ---------- 工作准则 ---------- */
.page-about .about-rules {
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
}

.page-about .about-rule {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-top: 1px solid var(--line-light);
}

.page-about .about-rule:last-child {
  border-bottom: 1px solid var(--line-light);
}

.page-about .about-rule__num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--red);
  font-variant-numeric: tabular-nums;
}

.page-about .about-rule__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.0625rem;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--indigo-900);
}

.page-about .about-rule__text {
  margin: 7px 0 0;
  max-width: 46ch;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .about-rule__text a {
  color: var(--indigo-500);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-rule__text a:hover,
.page-about .about-rule__text a:focus-visible {
  color: var(--red);
}

/* ---------- CTA ---------- */
.page-about .about-cta {
  display: grid;
  gap: 20px;
  margin-top: 40px;
  padding: 28px 22px 30px;
  background: var(--indigo-900);
  color: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.375rem;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.page-about .about-cta__text {
  margin: 10px 0 0;
  max-width: 40ch;
  font-size: 0.875rem;
  line-height: 1.78;
  color: rgba(246, 241, 231, 0.72);
}

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

/* ---------- 媒体查询 ---------- */
@media (min-width: 620px) {
  .page-about .about-hero {
    padding: 44px 0 64px;
  }

  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    max-width: 720px;
    gap: 18px 24px;
  }

  .page-about .about-scale {
    gap: 30px 26px;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 32px 30px 34px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 52px 0 76px;
  }

  .page-about .about-hero__lead {
    margin-left: auto;
    max-width: 33ch;
  }

  .page-about .about-era {
    grid-template-columns: 186px minmax(0, 1fr);
    gap: 58px;
    align-items: start;
  }

  .page-about .about-era__rail {
    position: sticky;
    top: 26px;
  }

  .page-about .about-era__toc {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
  }

  .page-about .about-era__toc .toc-link {
    display: block;
    padding: 7px 0;
  }

  .page-about .about-era__list {
    padding-left: 30px;
  }

  .page-about .about-era__list::before {
    left: 8px;
  }

  .page-about .era {
    padding: 26px 28px 24px 26px;
  }

  .page-about .era:nth-child(odd) {
    margin-right: 42px;
  }

  .page-about .era:nth-child(even) {
    margin-left: 30px;
  }

  .page-about .era::before {
    left: -34px;
  }

  .page-about .era__title {
    font-size: 1.5rem;
  }

  .page-about .about-team__figure {
    margin-top: 6px;
  }

  .page-about .about-quality {
    grid-template-columns: 300px minmax(0, 1fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-quality__figure {
    position: sticky;
    top: 26px;
  }

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

  .page-about .about-rules {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 46px;
  }

  .page-about .about-rule:nth-child(odd) {
    border-top: 1px solid var(--line-light);
  }

  .page-about .about-rule:last-child {
    grid-column: 1 / -1;
    border-bottom: none;
  }

  .page-about .about-rule:last-child .about-rule__text {
    max-width: 62ch;
  }
}

@media (min-width: 1140px) {
  .page-about .about-hero__title {
    max-width: 18ch;
  }

  .page-about .about-era {
    grid-template-columns: 200px minmax(0, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-role__fill,
  .page-about .about-era__toc .toc-link {
    transition: none;
  }
}

.page-about {
  --fill: currentColor;
}