.page-about {
  --ab-cut: 18px;
  display: block;
}

/* ============ 面包屑与首屏框景 ============ */
.page-about .og-breadcrumb {
  padding-top: clamp(14px, 2.4vw, 24px);
}

.page-about .ab-hero {
  padding-top: clamp(6px, 1.6vw, 18px);
}

.page-about .ab-hero__frame {
  padding: clamp(26px, 4.6vw, 62px) clamp(20px, 4vw, 56px) clamp(28px, 4.8vw, 58px);
  background-color: var(--night);
  background-image:
    linear-gradient(rgba(242, 245, 247, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(242, 245, 247, 0.05) 1px, transparent 1px),
    linear-gradient(135deg, #0B1B2B 0%, #122B45 100%);
  background-size: 24px 24px, 24px 24px, 100% 100%;
}

.page-about .ab-hero__title {
  margin: 14px 0 0;
  max-width: 22ch;
}

.page-about .ab-hero__lede {
  margin-top: clamp(16px, 2.4vw, 22px);
  max-width: 44rem;
}

.page-about .ab-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
  margin-top: clamp(26px, 4vw, 40px);
  padding-top: clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--line);
}

.page-about .ab-hero__num {
  display: block;
  font-family: var(--font-data);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.4vw, 2.125rem);
  line-height: 1.05;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-hero__label {
  display: block;
  margin-top: 8px;
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

/* ============ 通用区块标题 ============ */
.page-about .ab-head {
  max-width: 44rem;
  margin-bottom: clamp(24px, 3.6vw, 40px);
}

.page-about .ab-head__title {
  margin: 10px 0 0;
}

.page-about .ab-head__text {
  margin-top: 14px;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ============ 图像 ============ */
.page-about .og-media__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .ab-media {
  margin: 0 0 clamp(30px, 4.6vw, 52px);
}

/* ============ 时间线 ============ */
.page-about .ab-tl {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(18px, 2.6vw, 26px);
}

.page-about .ab-tl__node {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  align-items: start;
}

.page-about .ab-tl__year {
  display: block;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(1.9rem, 6.4vw, 2.5rem);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-node {
  background: linear-gradient(160deg, rgba(18, 43, 69, 0.92), rgba(11, 27, 43, 0.94));
  border: 1px solid var(--line-soft);
  clip-path: polygon(0 0, calc(100% - var(--ab-cut)) 0, 100% var(--ab-cut), 100% 100%, 0 100%);
  transition: border-color 280ms var(--ease);
}

.page-about .ab-node:hover {
  border-color: rgba(63, 224, 196, 0.45);
}

.page-about .ab-node[open] {
  border-color: rgba(224, 169, 75, 0.5);
}

.page-about .ab-node__sum {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px 18px;
  align-items: center;
  padding: clamp(16px, 2.4vw, 24px) clamp(18px, 2.6vw, 28px);
  cursor: pointer;
  list-style: none;
}

.page-about .ab-node__sum::-webkit-details-marker {
  display: none;
}

.page-about .ab-node__sum::marker {
  content: none;
}

.page-about .ab-node__sum:focus-visible {
  outline: 2px solid var(--violet);
  outline-offset: -2px;
}

.page-about .ab-node__kicker {
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--teal);
  text-transform: uppercase;
}

.page-about .ab-node__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.0625rem, 2.6vw, 1.25rem);
  line-height: 1.4;
  color: var(--mist);
}

.page-about .ab-node__chev {
  grid-column: 2;
  grid-row: 1 / span 2;
  width: 10px;
  height: 10px;
  margin-top: -4px;
  border-right: 1.5px solid var(--gold);
  border-bottom: 1.5px solid var(--gold);
  transform: rotate(45deg);
  transition: transform 260ms var(--ease);
}

.page-about .ab-node[open] .ab-node__chev {
  transform: rotate(-135deg);
}

.page-about .ab-node__panel {
  margin: 0 clamp(18px, 2.6vw, 28px);
  padding: clamp(14px, 2vw, 18px) 0 clamp(18px, 2.6vw, 26px);
  border-top: 1px dashed var(--line-soft);
}

.page-about .ab-node__panel p {
  margin: 0 0 12px;
  max-width: 40em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .ab-node__panel p:last-child {
  margin-bottom: 0;
}

@media (min-width: 900px) {
  .page-about .ab-tl__node {
    grid-template-columns: 20% minmax(0, 1fr);
    gap: 0 clamp(24px, 3.5vw, 48px);
  }

  .page-about .ab-tl__year {
    position: relative;
    font-size: clamp(2.2rem, 3.4vw, 3.1rem);
    text-align: right;
    padding-right: clamp(24px, 3.5vw, 48px);
    border-right: 1px solid var(--line);
  }

  .page-about .ab-tl__year::after {
    content: "";
    position: absolute;
    top: 9px;
    right: -4.5px;
    width: 8px;
    height: 8px;
    background: var(--night);
    border: 1px solid var(--gold);
    transform: rotate(45deg);
  }
}

/* ============ 分栏骨架 ============ */
.page-about .ab-split {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

@media (min-width: 940px) {
  .page-about .ab-split {
    grid-template-columns: 22% minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .ab-split__aside {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }
}

/* ============ 版本节奏 ============ */
.page-about .ab-data {
  display: grid;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-data__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: baseline;
  padding: 15px 0;
  border-bottom: 1px dashed var(--line-soft);
}

.page-about .ab-data__k {
  font-size: 0.875rem;
  letter-spacing: 0.04em;
  color: var(--ink-soft);
}

.page-about .ab-data__v {
  font-family: var(--font-data);
  font-size: 1rem;
  font-variant-numeric: tabular-nums;
  color: var(--gold);
  white-space: nowrap;
}

.page-about .ab-rhythm__note {
  margin: clamp(20px, 3vw, 28px) 0 0;
  max-width: 42em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ============ 数据治理（浅色分区） ============ */
.page-about .ab-gov {
  --ink: rgba(11, 27, 43, 0.88);
  --ink-soft: rgba(11, 27, 43, 0.66);
  --line: rgba(138, 107, 74, 0.48);
  --line-soft: rgba(11, 27, 43, 0.14);
}

.page-about .ab-gov__grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .ab-gov__text p {
  margin: 0 0 16px;
  max-width: 40em;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .ab-gov__text p:last-child {
  margin-bottom: 0;
}

.page-about .ab-gov__stats {
  display: grid;
  border-top: 1px solid var(--line);
}

.page-about .ab-stats__row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 18px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px dashed var(--line-soft);
}

.page-about .ab-stats__num {
  font-family: var(--font-data);
  font-weight: 700;
  font-size: clamp(1.25rem, 3vw, 1.5rem);
  line-height: 1;
  color: var(--sand);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-stats__label {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

@media (min-width: 880px) {
  .page-about .ab-gov__grid {
    grid-template-columns: 7fr 5fr;
  }
}

/* ============ 团队与分工 ============ */
.page-about .ab-bars {
  display: grid;
  gap: clamp(18px, 2.6vw, 26px);
}

.page-about .ab-bar__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 10px;
}

.page-about .ab-bar__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  color: var(--mist);
}

.page-about .ab-bar__val {
  font-family: var(--font-data);
  font-size: 0.875rem;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-bar__track {
  height: 10px;
  background: rgba(242, 245, 247, 0.09);
  overflow: hidden;
}

.page-about .ab-bar__fill {
  display: block;
  height: 100%;
}

.page-about .ab-bar__fill--a {
  width: 35.7%;
  background: linear-gradient(90deg, var(--sand), var(--gold));
}

.page-about .ab-bar__fill--b {
  width: 38.1%;
  background: linear-gradient(90deg, #1B5E6E, var(--teal));
}

.page-about .ab-bar__fill--c {
  width: 26.2%;
  background: linear-gradient(90deg, #4A3A96, var(--violet));
}

.page-about .ab-bar__desc {
  margin: 10px 0 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

.page-about .ab-team__media {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

/* ============ 服务范围 ============ */
.page-about .ab-region__grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .ab-region__media {
  margin: 0;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.page-about .ab-region__text p {
  margin: 14px 0 0;
  max-width: 40em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .ab-region__text .og-list {
  margin-top: 18px;
}

.page-about .ab-region__link a {
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 224, 196, 0.4);
}

.page-about .ab-region__link a:hover {
  border-bottom-color: var(--teal);
}

@media (min-width: 880px) {
  .page-about .ab-region__grid {
    grid-template-columns: 5fr 7fr;
    align-items: center;
  }
}

/* ============ 长期使用场景 ============ */
.page-about .ab-return__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-return__row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 18px;
  padding: clamp(20px, 3vw, 28px) 0;
  border-bottom: 1px dashed var(--line-soft);
}

.page-about .ab-return__num {
  padding-top: 5px;
  font-family: var(--font-data);
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--teal);
}

.page-about .ab-return__body h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.0625rem, 2.4vw, 1.1875rem);
  line-height: 1.4;
  color: var(--mist);
}

.page-about .ab-return__body p {
  margin: 0;
  max-width: 42em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

@media (min-width: 760px) {
  .page-about .ab-return__row {
    grid-template-columns: 64px minmax(0, 1fr);
    gap: 26px;
  }
}

/* ============ 结尾入口 ============ */
.page-about .ab-cta__box {
  display: grid;
  gap: clamp(22px, 3.4vw, 38px);
  padding: clamp(26px, 4vw, 48px);
  background: linear-gradient(135deg, rgba(18, 43, 69, 0.96), rgba(11, 27, 43, 0.96));
  border: 1px solid var(--line);
  clip-path: polygon(0 0, calc(100% - var(--ab-cut)) 0, 100% var(--ab-cut), 100% 100%, var(--ab-cut) 100%, 0 calc(100% - var(--ab-cut)));
}

.page-about .ab-cta__text p {
  margin: 14px 0 0;
  max-width: 38em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

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

@media (min-width: 880px) {
  .page-about .ab-cta__box {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

/* ============ 动效降级 ============ */
@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node,
  .page-about .ab-node__chev {
    transition: none;
  }
}