.page-about {
  --about-rail: 134px;
  --about-gap: 32px;
  --about-rule: 1px solid var(--line-300);
  background: var(--paper-50);
  color: var(--ink-900);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */

.page-about .breadcrumb ol,
.page-about .breadcrumb ul {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 30px;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(247, 245, 240, 0.5);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: rgba(247, 245, 240, 0.3);
}

.page-about .breadcrumb a {
  color: rgba(247, 245, 240, 0.8);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .breadcrumb a:hover {
  color: var(--amber-500);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: 30px 0 62px;
  background: linear-gradient(168deg, var(--indigo-900) 0%, #0c1024 68%, var(--ink-900) 100%);
  color: var(--paper-50);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--indigo-600) 0%, var(--celadon-600) 45%, var(--amber-500) 100%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 38px;
}

.page-about .about-hero .eyebrow {
  margin: 0;
  color: var(--amber-500);
}

.page-about .about-hero h1 {
  margin: 14px 0 20px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 8.4vw, 66px);
  line-height: 1.02;
  letter-spacing: 0.01em;
  color: var(--paper-0);
}

.page-about .about-hero__lede {
  max-width: 44em;
  margin: 0 0 28px;
  font-size: 16px;
  line-height: 1.82;
  color: rgba(247, 245, 240, 0.76);
}

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

.page-about .about-hero__panel {
  display: grid;
  grid-template-columns: 1fr;
  margin: 0;
  padding: 4px 20px 0;
  border: 1px solid rgba(247, 245, 240, 0.18);
  border-radius: var(--radius-lg);
  background: rgba(247, 245, 240, 0.045);
}

.page-about .about-hero__stat {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid rgba(247, 245, 240, 0.1);
}

.page-about .about-hero__stat dt {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: rgba(247, 245, 240, 0.6);
}

.page-about .about-hero__stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  color: var(--paper-0);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__stat dd .mono {
  font-size: 26px;
  color: var(--amber-500);
  margin-right: 4px;
}

.page-about .about-hero__panel-note {
  margin: 0;
  padding: 12px 0 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: rgba(247, 245, 240, 0.45);
}

/* ---------- 章节通用 ---------- */

.page-about .section {
  padding: 58px 0;
}

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--ink-900);
  margin-bottom: 26px;
}

.page-about .chapter-no {
  flex: none;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--amber-500);
}

.page-about .chapter-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 750;
  font-size: clamp(23px, 4.4vw, 36px);
  line-height: 1.16;
  letter-spacing: 0.01em;
  color: var(--ink-900);
}

.page-about .frame {
  overflow: hidden;
  margin: 0;
  border: var(--about-rule);
  border-radius: var(--radius-lg);
  background: var(--paper-0);
  box-shadow: var(--shadow-1);
}

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

.page-about .frame figcaption {
  padding: 10px 14px;
  border-top: var(--about-rule);
  font-size: 12px;
  letter-spacing: 0.03em;
  color: var(--slate-500);
}

.page-about .link {
  color: var(--indigo-600);
  text-decoration: none;
  border-bottom: 1px solid rgba(42, 58, 107, 0.35);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .link:hover {
  color: var(--amber-500);
  border-bottom-color: var(--amber-500);
}

/* ---------- 01 时间轴 ---------- */

.page-about .timeline {
  display: grid;
  margin: 0;
}

.page-about .timeline__item {
  display: grid;
  gap: 18px;
  padding: 30px 0;
  border-top: var(--about-rule);
}

.page-about .timeline__item:nth-child(1) {
  --stage: var(--indigo-900);
  border-top: 0;
  padding-top: 0;
}

.page-about .timeline__item:nth-child(2) {
  --stage: var(--indigo-600);
}

.page-about .timeline__item:nth-child(3) {
  --stage: var(--celadon-600);
}

.page-about .timeline__item:nth-child(4) {
  --stage: var(--amber-500);
}

.page-about .timeline__marker {
  position: relative;
  padding-left: 20px;
  border-left: 3px solid var(--stage, var(--indigo-900));
}

.page-about .timeline__marker::after {
  content: "";
  position: absolute;
  left: -8px;
  top: 7px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--stage, var(--indigo-900));
  box-shadow: 0 0 0 4px var(--paper-50);
}

.page-about .timeline__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 25px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--stage, var(--ink-900));
  font-variant-numeric: tabular-nums;
}

.page-about .timeline__phase {
  display: block;
  margin-top: 6px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--slate-500);
}

.page-about .timeline__body h3 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.3;
  letter-spacing: 0.01em;
  color: var(--ink-900);
}

.page-about .timeline__body > p {
  max-width: 60ch;
  margin: 0 0 18px;
  font-size: 15px;
  color: var(--ink-700);
}

.page-about .timeline__facts {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline__facts li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 10px 14px;
  border: var(--about-rule);
  border-left: 3px solid var(--stage, var(--indigo-900));
  border-radius: var(--radius);
  background: var(--paper-0);
  font-size: 13.5px;
  color: var(--ink-700);
}

.page-about .timeline__facts .mono {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--ink-900);
  font-variant-numeric: tabular-nums;
}

.page-about .timeline__figure {
  margin-top: 22px;
  max-width: 640px;
}

/* ---------- 02 供应链 ---------- */

.page-about .about-supply {
  background: var(--paper-0);
  border-top: var(--about-rule);
  border-bottom: var(--about-rule);
}

.page-about .supply-grid {
  display: grid;
  gap: 30px;
}

.page-about .supply-grid__lede {
  max-width: 60ch;
  margin: 0;
  font-size: 15.5px;
  color: var(--ink-700);
}

.page-about .supply-list {
  display: grid;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .supply-row {
  padding: 16px 0 18px;
  border-top: var(--about-rule);
}

.page-about .supply-row:last-child {
  border-bottom: var(--about-rule);
}

.page-about .supply-row dt {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.01em;
  color: var(--ink-900);
}

.page-about .supply-row dt .mono {
  font-family: var(--font-mono);
  font-size: 23px;
  color: var(--amber-500);
  font-variant-numeric: tabular-nums;
}

.page-about .supply-row dd {
  margin: 0;
  max-width: 58ch;
  font-size: 14.5px;
  color: var(--slate-500);
}

.page-about .supply-grid__figure {
  align-self: start;
}

/* ---------- 03 工程师团队 ---------- */

.page-about .crew-grid {
  display: grid;
  gap: 32px;
}

.page-about .crew-grid__intro > p {
  max-width: 58ch;
  margin: 0;
  font-size: 15.5px;
  color: var(--ink-700);
}

.page-about .crew-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  border: var(--about-rule);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--paper-0);
}

.page-about .crew-stats li {
  padding: 18px 16px;
  border-right: var(--about-rule);
  border-bottom: var(--about-rule);
}

.page-about .crew-stats li:nth-child(2n) {
  border-right: 0;
}

.page-about .crew-stats li:nth-last-child(-n + 2) {
  border-bottom: 0;
}

.page-about .crew-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--indigo-900);
  font-variant-numeric: tabular-nums;
}

.page-about .crew-stats__label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--slate-500);
}

.page-about .acc {
  margin-bottom: 10px;
  border: var(--about-rule);
  border-radius: var(--radius-lg);
  background: var(--paper-0);
  overflow: hidden;
  transition: box-shadow var(--dur) var(--ease);
}

.page-about .acc[open] {
  box-shadow: var(--shadow-1);
}

.page-about .acc summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 18px;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.01em;
  color: var(--ink-900);
}

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

.page-about .acc summary::before {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 19px;
  line-height: 1;
  color: var(--amber-500);
}

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

.page-about .acc p {
  margin: 0;
  padding: 14px 18px 18px;
  border-top: 1px dashed var(--line-300);
  font-size: 14.5px;
  color: var(--slate-500);
}

/* ---------- 04 区域网络 ---------- */

.page-about .about-network {
  position: relative;
  background: var(--indigo-900);
  color: var(--paper-50);
}

.page-about .about-network .chapter-head {
  border-bottom-color: rgba(247, 245, 240, 0.28);
}

.page-about .about-network .chapter-head h2 {
  color: var(--paper-0);
}

.page-about .network-grid {
  display: grid;
  gap: 30px;
}

.page-about .network-grid__text > p {
  max-width: 58ch;
  margin: 0 0 22px;
  font-size: 15.5px;
  color: rgba(247, 245, 240, 0.76);
}

.page-about .network-numbers {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  background: rgba(247, 245, 240, 0.16);
  border: 1px solid rgba(247, 245, 240, 0.16);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .network-numbers li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 12px;
  background: var(--indigo-900);
}

.page-about .network-numbers .mono {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--amber-500);
  font-variant-numeric: tabular-nums;
}

.page-about .network-numbers span:last-child {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(247, 245, 240, 0.6);
}

.page-about .network-grid__note {
  margin: 0;
  font-size: 14px;
  color: rgba(247, 245, 240, 0.66);
}

.page-about .about-network .link {
  color: var(--amber-500);
  border-bottom-color: rgba(245, 158, 11, 0.45);
}

.page-about .about-network .link:hover {
  color: var(--paper-0);
  border-bottom-color: var(--paper-0);
}

.page-about .network-grid__map {
  border-color: rgba(247, 245, 240, 0.2);
  background: #0c1024;
  box-shadow: var(--shadow-2);
}

.page-about .region-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .region-list__item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 15px;
  border: 1px solid rgba(247, 245, 240, 0.18);
  border-radius: var(--radius);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .region-list__item:hover {
  border-color: var(--celadon-600);
  background: rgba(47, 143, 122, 0.14);
}

.page-about .region-list__no {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--celadon-600);
}

.page-about .region-list__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.04em;
  color: var(--paper-0);
}

/* ---------- 05 资质 ---------- */

.page-about .credit-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: credit;
}

.page-about .credit-list__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px 18px;
  align-items: start;
  padding: 22px 0;
  border-top: var(--about-rule);
}

.page-about .credit-list__item:last-child {
  border-bottom: var(--about-rule);
}

.page-about .credit-list__no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--amber-500);
  padding-top: 5px;
}

.page-about .credit-list__body h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.01em;
  color: var(--ink-900);
}

.page-about .credit-list__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  color: var(--slate-500);
}

.page-about .credit-list__item .tag {
  grid-column: 2 / -1;
  justify-self: start;
}

/* ---------- 06 合作生态 ---------- */

.page-about .about-partner {
  background: var(--paper-0);
  border-top: var(--about-rule);
}

.page-about .partner-grid {
  display: grid;
  gap: 32px;
}

.page-about .partner-grid__text > p {
  max-width: 60ch;
  margin: 0 0 24px;
  font-size: 15.5px;
  color: var(--ink-700);
}

.page-about .partner-scenes {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .partner-scenes li {
  padding: 16px 0 18px;
  border-top: var(--about-rule);
}

.page-about .partner-scenes li:last-child {
  border-bottom: var(--about-rule);
}

.page-about .partner-scenes h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.02em;
  color: var(--indigo-600);
}

.page-about .partner-scenes p {
  margin: 0;
  max-width: 56ch;
  font-size: 14.5px;
  color: var(--slate-500);
}

.page-about .partner-promise {
  align-self: start;
  padding: 24px 22px;
  border: var(--about-rule);
  border-top: 4px solid var(--celadon-600);
  border-radius: var(--radius-lg);
  background: var(--paper-50);
  box-shadow: var(--shadow-1);
}

.page-about .partner-promise h3 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: 0.03em;
  color: var(--ink-900);
}

.page-about .partner-promise__list {
  display: grid;
  gap: 0;
  margin: 0;
}

.page-about .partner-promise__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 12px 0;
  border-top: var(--about-rule);
}

.page-about .partner-promise__row:last-child {
  border-bottom: var(--about-rule);
}

.page-about .partner-promise__row dt {
  font-size: 13.5px;
  letter-spacing: 0.03em;
  color: var(--slate-500);
}

.page-about .partner-promise__row dd {
  margin: 0;
  font-size: 14px;
  color: var(--ink-900);
}

.page-about .partner-promise__row dd .mono {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  color: var(--amber-500);
  font-variant-numeric: tabular-nums;
}

.page-about .partner-promise__note {
  margin: 18px 0 0;
  font-size: 13px;
  color: var(--slate-500);
}

/* ---------- 收尾行动区 ---------- */

.page-about .about-cta {
  padding-top: 8px;
  padding-bottom: 72px;
}

.page-about .about-cta__box {
  display: grid;
  gap: 24px;
  padding: 30px 24px;
  border: var(--about-rule);
  border-left: 6px solid var(--amber-500);
  border-radius: var(--radius-lg);
  background: var(--paper-0);
  box-shadow: var(--shadow-1);
}

.page-about .about-cta__text h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 750;
  font-size: clamp(22px, 4vw, 32px);
  line-height: 1.18;
  color: var(--ink-900);
}

.page-about .about-cta__text p {
  max-width: 60ch;
  margin: 0;
  font-size: 15px;
  color: var(--slate-500);
}

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

/* ---------- 响应式 ---------- */

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

  .page-about .credit-list__item {
    grid-template-columns: auto minmax(0, 1fr) auto;
  }

  .page-about .credit-list__item .tag {
    grid-column: 3;
    justify-self: end;
    align-self: center;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-gap: 44px;
  }

  .page-about .about-hero {
    padding: 36px 0 78px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    gap: 56px;
    align-items: end;
  }

  .page-about .section {
    padding: 82px 0;
  }

  .page-about .timeline__item {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    padding: 42px 0;
    align-items: start;
  }

  .page-about .timeline__item:nth-child(even) .timeline__body {
    padding-left: 26px;
    border-left: 1px dashed var(--line-300);
  }

  .page-about .supply-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .crew-grid {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .network-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.08fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .region-list {
    grid-template-columns: repeat(7, minmax(0, 1fr));
    margin-top: 44px;
  }

  .page-about .region-list__item {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .page-about .partner-grid {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, 1fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-cta__box {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 36px;
    padding: 40px 36px;
  }

  .page-about .about-cta__actions {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (min-width: 1180px) {
  .page-about .timeline__item:nth-child(even) .timeline__body {
    padding-left: 56px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .acc,
  .page-about .region-list__item,
  .page-about .link,
  .page-about .breadcrumb a {
    transition: none;
  }
}