.page-about {
  --ab-pad: 22px;
  --ab-ink: #06100d;
  --ab-ink-soft: #4b5d54;
  background: var(--dfb-900);
}

/* 面包屑 */
.page-about .ab-crumb {
  background: var(--dfb-900);
  padding-block: 14px 6px;
}
.page-about .ab-crumb .dfb-breadcrumb {
  font-size: 12px;
}

/* 首屏 */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(28px, 6vw, 64px) clamp(36px, 6vw, 68px);
  background:
    radial-gradient(110% 80% at 8% 0%, rgba(60, 242, 214, 0.12), transparent 60%),
    radial-gradient(80% 70% at 100% 20%, rgba(255, 122, 26, 0.10), transparent 62%),
    var(--dfb-900);
}
.page-about .ab-hero::after {
  content: "";
  position: absolute;
  right: -16%;
  top: 12%;
  width: 44%;
  aspect-ratio: 1 / 1;
  border: 1px solid rgba(60, 242, 214, 0.18);
  transform: rotate(18deg);
  pointer-events: none;
}
.page-about .ab-hero__kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--dfb-orange);
}
.page-about .ab-hero__title {
  position: relative;
  z-index: 1;
  margin: 14px 0 20px;
  font-size: clamp(34px, 8.4vw, 88px);
  line-height: 1.03;
  letter-spacing: -0.025em;
  font-weight: 300;
  color: var(--dfb-paper);
}
.page-about .ab-hero__title strong {
  display: block;
  font-weight: 800;
  color: var(--dfb-cyan);
}
.page-about .ab-hero__lead {
  position: relative;
  z-index: 1;
  max-width: 58ch;
  margin: 0;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: var(--dfb-mist);
}
.page-about .ab-hero__stats {
  position: relative;
  z-index: 1;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 34px 0 0;
  padding: 0;
  background: var(--dfb-line);
  border: 1px solid var(--dfb-line);
}
.page-about .ab-hero__stats li {
  background: var(--dfb-900);
  padding: 16px 14px 18px;
}
.page-about .ab-stat__num {
  display: block;
  font-size: clamp(26px, 6.4vw, 40px);
  font-weight: 700;
  line-height: 1.05;
  color: var(--dfb-cyan);
  letter-spacing: -0.02em;
}
.page-about .ab-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--dfb-mist);
}

/* 档案主轴 */
.page-about .ab-archive {
  background: var(--dfb-900);
  padding-block: clamp(20px, 4vw, 40px) clamp(48px, 7vw, 88px);
}
.page-about .ab-spine {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: clamp(26px, 4vw, 52px);
  padding-left: var(--ab-pad);
  border-left: 1px solid var(--dfb-line);
}
.page-about .ab-card {
  position: relative;
  background: var(--dfb-800);
  border: 1px solid var(--dfb-line);
  padding: clamp(20px, 3.2vw, 36px);
  color: var(--dfb-paper);
}
.page-about .ab-card::before {
  content: "";
  position: absolute;
  left: calc(var(--ab-pad) * -1 - 6px);
  top: 28px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--dfb-900);
  border: 2px solid var(--dfb-cyan);
}
.page-about .ab-card--paper {
  background: var(--dfb-paper);
  border-color: var(--dfb-700);
  color: var(--ab-ink);
}
.page-about .ab-card--paper::before {
  border-color: var(--dfb-orange);
}
.page-about .ab-card .dfb-kicker {
  color: var(--dfb-orange);
}
.page-about .ab-card__title {
  margin: 8px 0 18px;
  font-size: clamp(21px, 3.6vw, 32px);
  line-height: 1.25;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--dfb-paper);
}
.page-about .ab-card--paper .ab-card__title {
  color: var(--ab-ink);
}
.page-about .ab-card p {
  max-width: 62ch;
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--dfb-mist);
}
.page-about .ab-card--paper p {
  color: var(--ab-ink-soft);
}
.page-about .ab-card p strong {
  color: var(--dfb-cyan);
  font-weight: 700;
}
.page-about .ab-card--paper p strong {
  color: var(--dfb-700);
}
.page-about .ab-card__foot {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid rgba(7, 17, 14, 0.16);
  font-size: 14px;
  color: var(--ab-ink);
}

/* 数据生产线 */
.page-about .ab-flow-svg {
  display: block;
  width: 100%;
  height: auto;
  margin: 4px 0 20px;
}
.page-about .ab-flow-svg__line {
  stroke: var(--dfb-line);
  stroke-width: 1;
}
.page-about .ab-flow-svg__node circle {
  fill: var(--dfb-900);
  stroke: var(--dfb-cyan);
  stroke-width: 1.5;
}
.page-about .ab-flow-svg__idx {
  fill: var(--dfb-cyan);
  font-family: var(--dfb-font-mono);
  font-size: 13px;
  font-weight: 700;
}
.page-about .ab-flow-svg__label {
  fill: var(--dfb-paper);
  font-size: 15px;
  font-weight: 700;
}
.page-about .ab-flow-svg__note {
  fill: var(--dfb-mist);
  font-size: 11px;
}
.page-about .ab-pipeline__grid {
  display: grid;
  gap: 22px;
}
.page-about .ab-pipeline__figure {
  margin: 0;
}
.page-about .ab-pipeline__figure img {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}

/* 团队 */
.page-about .ab-team__grid {
  display: grid;
  gap: 22px;
}
.page-about .ab-team__figure {
  margin: 0;
}
.page-about .ab-team__figure img {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}
.page-about .ab-team__nums {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 20px 0 0;
  padding: 0;
  background: var(--dfb-line);
  border: 1px solid var(--dfb-line);
}
.page-about .ab-team__nums li {
  background: var(--dfb-900);
  padding: 14px 12px 16px;
}
.page-about .ab-team__num {
  display: block;
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--dfb-lime);
}
.page-about .ab-team__cap {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  color: var(--dfb-mist);
}

/* 版本年表 */
.page-about .ab-timeline__figure {
  margin: 0 0 24px;
}
.page-about .ab-timeline__figure img {
  width: 100%;
  max-width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}
.page-about .ab-timeline__filter {
  flex-wrap: wrap;
}
.page-about .ab-timeline {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.page-about .ab-node__year {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--dfb-lime);
}
.page-about .ab-node__panel {
  background: var(--dfb-900);
  border: 1px solid var(--dfb-line);
  border-left: 2px solid var(--dfb-700);
  padding: 16px 16px 18px;
}
.page-about .ab-node__title {
  margin: 0 0 8px;
  font-size: 16px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--dfb-paper);
}
.page-about .ab-node__panel p {
  margin: 0;
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--dfb-mist);
}

/* 覆盖范围纸面层 */
.page-about .ab-scope {
  position: relative;
  background: var(--dfb-paper);
  color: var(--ab-ink);
  padding-block: clamp(58px, 8vw, 100px);
  clip-path: polygon(0 24px, 100% 0, 100% 100%, 0 100%);
}
.page-about .ab-scope__kicker {
  margin: 0;
  color: var(--dfb-orange);
}
.page-about .ab-scope__title {
  margin: 12px 0 16px;
  max-width: 24ch;
  font-size: clamp(25px, 4.6vw, 46px);
  line-height: 1.18;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--ab-ink);
}
.page-about .ab-scope__lead {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ab-ink-soft);
}
.page-about .ab-scope__grid {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  padding: 0;
  background: rgba(7, 17, 14, 0.16);
  border: 1px solid rgba(7, 17, 14, 0.16);
}
.page-about .ab-scope__item {
  background: var(--dfb-paper);
  padding: 18px 14px 20px;
}
.page-about .ab-scope__fig {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 0;
}
.page-about .ab-scope__num {
  font-size: clamp(28px, 6vw, 42px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--dfb-700);
}
.page-about .ab-scope__unit {
  font-size: 13px;
  font-weight: 700;
  color: var(--dfb-orange);
}
.page-about .ab-scope__label {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--ab-ink-soft);
}
.page-about .ab-scope__tail {
  margin: 28px 0 0;
  padding-top: 20px;
  border-top: 1px solid rgba(7, 17, 14, 0.16);
  font-size: 14px;
  line-height: 1.85;
  color: var(--ab-ink-soft);
}

/* 服务承诺 */
.page-about .ab-promise {
  background: var(--dfb-900);
  padding-block: clamp(46px, 7vw, 88px);
}
.page-about .ab-promise__grid {
  display: grid;
  gap: 28px;
}
.page-about .ab-promise__title {
  margin: 12px 0 16px;
  font-size: clamp(25px, 4.4vw, 42px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--dfb-paper);
}
.page-about .ab-promise__lead {
  margin: 0 0 18px;
  max-width: 46ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--dfb-mist);
}
.page-about .ab-promise__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.page-about .ab-promise__list li {
  position: relative;
  padding: 18px 18px 18px 22px;
  background: var(--dfb-800);
  border: 1px solid var(--dfb-line);
  border-left: 3px solid var(--dfb-cyan);
}
.page-about .ab-promise__item-title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--dfb-paper);
}
.page-about .ab-promise__list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--dfb-mist);
}
.page-about .ab-promise__contact {
  margin: 30px 0 0;
  padding-top: 22px;
  border-top: 1px solid var(--dfb-line);
  font-family: var(--dfb-font-mono);
  font-size: 13px;
  line-height: 1.9;
  color: var(--dfb-mist);
}
.page-about .ab-link {
  color: var(--dfb-cyan);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid rgba(60, 242, 214, 0.4);
}
.page-about .ab-link:hover,
.page-about .ab-link:focus-visible {
  border-bottom-color: var(--dfb-cyan);
}

/* 收尾行动 */
.page-about .ab-cta {
  background: linear-gradient(120deg, #0E2019 0%, #14322A 58%, #0E2019 100%);
  border-top: 1px solid var(--dfb-line);
  padding-block: clamp(40px, 6vw, 72px);
}
.page-about .ab-cta__inner {
  display: grid;
  gap: 24px;
  align-items: center;
}
.page-about .ab-cta__title {
  margin: 0 0 12px;
  font-size: clamp(22px, 3.6vw, 34px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--dfb-paper);
}
.page-about .ab-cta__text p {
  margin: 0;
  max-width: 48ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--dfb-mist);
}
.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* 平板及以上 */
@media (min-width: 720px) {
  .page-about {
    --ab-pad: 36px;
  }
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-team__nums {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-scope__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-node {
    display: grid;
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 20px;
    align-items: start;
  }
  .page-about .ab-node__year {
    margin: 0;
    padding-top: 4px;
    font-size: 18px;
    text-align: right;
    position: sticky;
    top: 92px;
  }
  .page-about .ab-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
  }
}

/* 桌面及以上：档案卡由窄到宽 */
@media (min-width: 900px) {
  .page-about .ab-hero__lead {
    max-width: 52ch;
  }
  .page-about .ab-spine > .ab-card:nth-child(1) {
    max-width: 78%;
  }
  .page-about .ab-spine > .ab-card:nth-child(2) {
    max-width: 88%;
  }
  .page-about .ab-spine > .ab-card:nth-child(3) {
    max-width: 94%;
  }
  .page-about .ab-spine > .ab-card:nth-child(n + 4) {
    max-width: 100%;
  }
  .page-about .ab-pipeline__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 30px;
    align-items: start;
  }
  .page-about .ab-team__grid {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 30px;
    align-items: start;
  }
  .page-about .ab-scope__title {
    max-width: 26ch;
  }
  .page-about .ab-promise__grid {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 44px;
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node__year {
    position: static;
  }
}