.page-about {
  --about-body: #C4CEDE;
  --about-rail: 240px;
  --about-hair: 1px solid var(--ink-700);
  padding-bottom: clamp(64px, 9vw, 104px);
}

.page-about img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* 面包屑 */
.page-about .about-crumb {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--graphite);
}

.page-about .about-crumb a {
  color: var(--graphite);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

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

.page-about .about-crumb-sep {
  color: var(--ink-700);
}

.page-about .about-crumb [aria-current="page"] {
  color: var(--paper);
}

/* 首屏 */
.page-about .about-intro {
  padding: clamp(26px, 5vw, 46px) 0 clamp(46px, 7vw, 76px);
  border-bottom: var(--about-hair);
}

.page-about .about-intro h1 {
  margin: 20px 0 0;
  max-width: 13em;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(34px, 6.4vw, 74px);
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-lede {
  margin: 26px 0 0;
  max-width: 60ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .about-keyfigs {
  margin: 44px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ink-700);
  border: 1px solid var(--ink-700);
}

.page-about .about-keyfigs > div {
  background: var(--ink-900);
  padding: 18px 16px 20px;
}

.page-about .about-keyfigs dt {
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--graphite);
}

.page-about .about-keyfigs dd {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.5;
  color: var(--graphite);
}

.page-about .about-keyfigs dd .mono {
  font-size: 24px;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

/* 演进章节 */
.page-about .about-evolution {
  padding: clamp(52px, 8vw, 96px) 0 0;
}

.page-about .about-banner {
  margin: 0 0 clamp(38px, 6vw, 72px);
  aspect-ratio: 16 / 9;
  border: 1px solid var(--ink-700);
  overflow: hidden;
}

.page-about .about-banner img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-rail-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-years {
  border-top: 2px solid var(--orange);
  padding-top: 16px;
}

.page-about .about-years-title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--graphite);
}

.page-about .about-years ol {
  list-style: none;
  margin: 0;
  padding: 0 0 8px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
}

.page-about .about-years li {
  flex: 0 0 auto;
}

.page-about .about-years a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 13px;
  border: 1px solid var(--ink-700);
  font-size: 14px;
  color: var(--graphite);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-years a .mono {
  font-size: 13px;
  color: var(--orange);
}

.page-about .about-years a:hover,
.page-about .about-years a:focus-visible {
  color: var(--paper);
  border-color: var(--cyan);
  background: var(--ink-800);
}

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

.page-about .stage {
  padding: 32px 0 36px;
  border-top: var(--about-hair);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .about-stages .stage:last-of-type {
  border-bottom: var(--about-hair);
}

.page-about .stage-num {
  margin: 0;
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--orange);
}

.page-about .stage-year {
  margin: 0 0 12px;
  font-size: clamp(30px, 5vw, 46px);
  line-height: 1;
  color: var(--graphite);
  font-variant-numeric: tabular-nums;
}

.page-about .stage h3 {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(20px, 2.4vw, 27px);
  line-height: 1.38;
  color: var(--paper);
}

.page-about .stage-body p {
  margin: 0;
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .stage-points {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .stage-points li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--paper);
}

.page-about .stage-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .82em;
  width: 10px;
  height: 1px;
  background: var(--cyan);
}

.page-about .stage-points .mono,
.page-about .stage-body .mono {
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .about-merge {
  margin-top: 48px;
  padding-top: 30px;
  border-top: 2px solid var(--orange);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-merge h3 {
  margin: 0 0 16px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(21px, 2.6vw, 30px);
  line-height: 1.36;
  color: var(--paper);
}

.page-about .about-merge p {
  margin: 0 0 14px;
  max-width: 56ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .about-link {
  display: inline-block;
  margin-top: 6px;
  padding-bottom: 3px;
  font-size: 15px;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 211, 200, .35);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--orange);
}

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

.page-about .about-axis img {
  width: 100%;
  border: 1px solid var(--ink-700);
}

.page-about .about-axis .media-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--graphite);
}

/* 档案库 */
.page-about .about-archive {
  padding: clamp(60px, 9vw, 104px) 0 0;
}

.page-about .about-archive-grid {
  margin-top: 38px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ink-700);
  border: 1px solid var(--ink-700);
}

.page-about .archive-fact {
  background: var(--ink-900);
  padding: 24px 20px 26px;
}

.page-about .archive-fact .mono {
  display: block;
  font-size: 26px;
  line-height: 1;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .archive-fact h3 {
  margin: 14px 0 8px;
  font-size: 16px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .archive-fact p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-body);
}

.page-about .about-cats {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-cats li {
  padding: 7px 12px;
  border: 1px solid var(--ink-700);
  background: var(--ink-800);
  font-size: 14px;
  line-height: 1.4;
  color: var(--about-body);
}

/* 服务网络 */
.page-about .about-network {
  padding: clamp(60px, 9vw, 104px) 0 0;
}

.page-about .network-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  align-items: start;
}

.page-about .about-map {
  margin: 0;
  aspect-ratio: 3 / 2;
  border: 1px solid var(--ink-700);
  overflow: hidden;
}

.page-about .about-map img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .network-text {
  min-width: 0;
}

.page-about .network-nodes {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--ink-700);
  border-top: 1px solid var(--ink-700);
  border-bottom: 1px solid var(--ink-700);
}

.page-about .network-nodes li {
  background: var(--ink-900);
  padding: 12px 14px;
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  font-size: 15px;
  line-height: 1.7;
  color: var(--about-body);
  transition: background-color var(--dur) var(--ease);
}

.page-about .network-nodes li:hover {
  background: var(--ink-800);
}

.page-about .network-nodes b {
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 14px;
  letter-spacing: .02em;
  color: var(--paper);
}

/* 协作生态 */
.page-about .about-partners {
  padding: clamp(56px, 8vw, 96px) 0 0;
}

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

.page-about .partner-col {
  padding-top: 18px;
  border-top: 1px solid var(--ink-700);
}

.page-about .partner-col--note {
  border-top-color: var(--cyan);
}

.page-about .partner-num {
  margin: 0;
  font-size: clamp(34px, 5vw, 52px);
  line-height: 1;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .partner-col--note .partner-num {
  color: var(--cyan);
}

.page-about .partner-col h3 {
  margin: 14px 0 10px;
  font-size: 17px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .partner-col p:last-child {
  margin: 0;
  max-width: 42ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-body);
}

/* 资质（浅底章节） */
.page-about .about-band {
  margin-top: clamp(60px, 9vw, 104px);
  padding: clamp(52px, 8vw, 86px) 0;
}

.page-about .about-band--mist {
  background: var(--mist);
}

.page-about .about-band--mist .eyebrow {
  color: var(--ink-700);
}

.page-about .about-band--mist h2 {
  color: var(--ink-900);
}

.page-about .about-band--mist .section-head p {
  color: #44506A;
}

.page-about .credit-grid {
  margin-top: 34px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.page-about .credit-item {
  padding-top: 18px;
  border-top: 2px solid var(--orange);
}

.page-about .credit-item h3 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 21px;
  line-height: 1.4;
  color: var(--ink-900);
}

.page-about .credit-item p {
  margin: 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.82;
  color: #3C4761;
}

/* 服务对象规模 */
.page-about .about-scale {
  padding: clamp(60px, 9vw, 104px) 0 0;
}

.page-about .scale-grid {
  margin-top: 36px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ink-700);
  border-top: 1px solid var(--ink-700);
  border-bottom: 1px solid var(--ink-700);
}

.page-about .scale-item {
  background: var(--ink-900);
  padding: 26px 20px 28px;
}

.page-about .scale-num {
  margin: 0;
  font-size: clamp(30px, 4.6vw, 48px);
  line-height: 1;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .scale-label {
  margin: 14px 0 0;
  max-width: 30ch;
  font-size: 15px;
  line-height: 1.72;
  color: var(--about-body);
}

.page-about .about-scale-note {
  margin: 32px 0 0;
  max-width: 66ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .about-scale-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 211, 200, .35);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-scale-note a:hover,
.page-about .about-scale-note a:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--orange);
}

/* 结尾动作 */
.page-about .about-cta {
  padding: clamp(56px, 8vw, 96px) 0 0;
}

.page-about .cta-inner {
  padding: clamp(26px, 4vw, 48px);
  border: 1px solid var(--ink-700);
  border-left: 3px solid var(--orange);
  background: var(--ink-800);
  display: grid;
  gap: 18px;
}

.page-about .cta-inner h2 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(22px, 3vw, 34px);
  line-height: 1.32;
  color: var(--paper);
}

.page-about .cta-inner p {
  margin: 0;
  max-width: 56ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}

/* 响应式 */
@media (min-width: 640px) {
  .page-about .about-archive-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .stage {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: 32px;
    padding: 40px 0 48px;
  }

  .page-about .stage-num {
    padding-top: 8px;
  }

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

@media (min-width: 800px) {
  .page-about .credit-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 44px;
  }

  .page-about .partner-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 32px;
  }
}

@media (min-width: 900px) {
  .page-about .scale-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-rail-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-years {
    position: sticky;
    top: 120px;
  }

  .page-about .about-years ol {
    flex-direction: column;
    gap: 0;
    overflow-x: visible;
    padding-bottom: 0;
  }

  .page-about .about-years a {
    border: 0;
    border-left: 1px solid var(--ink-700);
    padding: 12px 14px;
  }

  .page-about .about-years a:hover,
  .page-about .about-years a:focus-visible {
    border-left-color: var(--cyan);
  }

  .page-about .about-merge {
    grid-template-columns: minmax(0, 1fr) 280px;
    gap: 48px;
    align-items: start;
  }

  .page-about .network-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 56px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-archive-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}