.page-about {
  display: block;
  padding: 0 0 96px;
  background: var(--ink);
  color: var(--sand);
  overflow-x: hidden;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 26px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--rock);
}

.page-about .about-crumb a {
  color: var(--rock);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .about-crumb a:hover,
.page-about .about-crumb a:focus-visible {
  color: var(--amber-lift);
  border-bottom-color: var(--amber-lift);
}

.page-about .about-crumb__sep {
  color: var(--ink-2);
}

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

/* ---------- 题头 ---------- */
.page-about .about-head {
  padding: 34px 0 52px;
  border-bottom: 3px solid var(--ink-2);
}

.page-about .about-head__kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 22px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .about-head__tick {
  display: block;
  width: 34px;
  height: 4px;
  background: var(--amber);
}

.page-about .about-head h1 {
  margin: 0 0 26px;
  max-width: 16ch;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(38px, 9vw, 88px);
  line-height: .98;
  letter-spacing: -.02em;
  color: var(--sand);
}

.page-about .about-head__lede {
  margin: 0;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--sand-dim);
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

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

/* ---------- 章节刻度 ---------- */
.page-about .about-rail {
  border-bottom: 3px solid var(--ink-2);
}

.page-about .about-rail__title {
  display: none;
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--rock);
}

.page-about .about-rail__list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 14px 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 14px;
  font-size: 13px;
  line-height: 1.2;
  color: var(--rock);
  text-decoration: none;
  white-space: nowrap;
  background: var(--ink-2);
  border: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--sand);
  border-color: var(--amber);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--amber);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding: 56px 0;
  border-bottom: 3px solid var(--ink-2);
}

.page-about .about-section--last {
  border-bottom: 0;
}

.page-about .about-sec-head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 26px;
}

.page-about .about-sec-num {
  flex: none;
  padding-top: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--amber);
}

.page-about .about-sec-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 5.2vw, 44px);
  line-height: 1.1;
  letter-spacing: -.01em;
  color: var(--sand);
}

.page-about .about-prose {
  margin: 0 0 20px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--sand-dim);
}

.page-about .about-prose:last-child {
  margin-bottom: 0;
}

/* ---------- 服务能力块 ---------- */
.page-about .about-cap {
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
  border-top: 3px solid var(--ink-2);
}

.page-about .about-cap__item {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 0 16px;
  padding: 24px 0;
  border-bottom: 1px solid var(--ink-2);
}

.page-about .about-cap__item:last-child {
  border-bottom: 0;
}

.page-about .about-cap__idx {
  font-family: var(--font-mono);
  font-size: 24px;
  line-height: 1;
  padding-top: 2px;
  color: var(--amber);
}

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

.page-about .about-cap__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.25;
  color: var(--sand);
}

.page-about .about-cap__text {
  margin: 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--sand-dim);
}

/* ---------- 三道校对流程图 ---------- */
.page-about .about-flow-wrap {
  margin: 32px 0 0;
  padding: 20px 18px;
  background: var(--ink-deep);
  border: 3px solid var(--ink-2);
  overflow-x: auto;
}

.page-about .about-flow {
  display: block;
  width: 100%;
  min-width: 680px;
  height: auto;
}

.page-about .about-flow__node rect {
  fill: var(--ink-2);
  stroke: var(--edge);
  stroke-width: 3;
  transition: fill 220ms var(--ease);
}

.page-about .about-flow__node:hover rect {
  fill: #1B3450;
}

.page-about .about-flow__step {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .14em;
  fill: var(--amber);
}

.page-about .about-flow__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  fill: var(--sand);
}

.page-about .about-flow__desc {
  font-family: var(--font-body);
  font-size: 14px;
  fill: var(--sand-dim);
}

.page-about .about-flow__time {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .04em;
  fill: var(--cyan);
}

.page-about .about-flow__arrow {
  fill: var(--amber);
}

/* ---------- 引用块 ---------- */
.page-about .about-quote {
  margin: 30px 0 0;
  padding: 24px 22px;
  background: var(--ink-2);
  border-left: 5px solid var(--amber);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 3.4vw, 25px);
  line-height: 1.5;
  color: var(--sand);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 32px 0 0;
  background: var(--ink-deep);
  border: 3px solid var(--ink-2);
}

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

.page-about .about-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--rock);
  border-top: 1px solid var(--ink-2);
}

.page-about .about-figure--compact {
  margin-top: 0;
}

/* ---------- 演进时间线 ---------- */
.page-about .about-timeline {
  margin-top: 28px;
  border-top: 3px solid var(--ink-2);
}

.page-about .about-tl {
  border-bottom: 3px solid var(--ink-2);
  border-left: 5px solid transparent;
  transition: border-left-color 220ms var(--ease), background 220ms var(--ease);
}

.page-about .about-tl[open] {
  border-left-color: var(--amber);
  background: var(--ink-2);
}

.page-about .about-tl > summary {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 22px;
  gap: 6px 16px;
  align-items: center;
  padding: 20px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-tl > summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1;
  text-align: right;
  color: var(--amber);
}

.page-about .about-tl[open] > summary::after {
  content: "–";
}

.page-about .about-tl__stage {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--amber-lift);
}

.page-about .about-tl__title {
  display: block;
  margin-top: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.35;
  color: var(--sand);
}

.page-about .about-tl__body {
  padding: 0 16px 24px;
}

.page-about .about-tl__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--sand-dim);
}

/* ---------- 5/7 非对称分栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

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

.page-about .about-split__text .about-prose:last-child {
  margin-bottom: 0;
}

/* ---------- 数字块 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 32px;
  border-top: 3px solid var(--ink-2);
  border-left: 3px solid var(--ink-2);
}

.page-about .about-stat {
  padding: 20px 16px 24px;
  border-right: 3px solid var(--ink-2);
  border-bottom: 3px solid var(--ink-2);
}

.page-about .about-stat__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(30px, 7vw, 50px);
  line-height: 1;
  color: var(--amber);
}

.page-about .about-stat__num--oasis {
  color: var(--oasis);
}

.page-about .about-stat__unit {
  margin-left: 6px;
  font-size: 13px;
  color: var(--sand-dim);
}

.page-about .about-stat__key {
  display: block;
  margin-top: 14px;
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--rock);
}

/* ---------- 三条标准 ---------- */
.page-about .about-rules {
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rule {
  padding: 24px 0 24px 20px;
  border-left: 5px solid var(--amber);
  border-bottom: 1px solid var(--ink-2);
}

.page-about .about-rule:last-child {
  border-bottom: 0;
  padding-bottom: 8px;
}

.page-about .about-rule__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.3;
  color: var(--sand);
}

.page-about .about-rule__text {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--sand-dim);
}

/* ---------- 后续入口 ---------- */
.page-about .about-next {
  padding: 52px 0 0;
}

.page-about .about-next__heading {
  margin: 0 0 22px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--rock);
}

.page-about .about-next__list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 3px solid var(--ink-2);
}

.page-about .about-next__item {
  border-bottom: 3px solid var(--ink-2);
}

.page-about .about-next__link {
  display: block;
  padding: 20px 4px;
  text-decoration: none;
  transition: background 200ms var(--ease), padding-left 200ms var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--ink-2);
  padding-left: 16px;
}

.page-about .about-next__label {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.25;
  color: var(--amber-lift);
}

.page-about .about-next__desc {
  display: block;
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--rock);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 700px) {
  .page-about .about-section {
    padding: 68px 0;
  }

  .page-about .about-cap__item {
    grid-template-columns: 64px minmax(0, 1fr);
    gap: 0 22px;
    padding: 32px 0;
  }

  .page-about .about-cap__idx {
    font-size: 30px;
  }

  .page-about .about-cap__title {
    font-size: 24px;
  }

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

  .page-about .about-stats--wide {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-stat {
    padding: 26px 20px 30px;
  }

  .page-about .about-tl > summary {
    padding: 24px 22px;
  }

  .page-about .about-tl__body {
    padding: 0 22px 28px 22px;
  }

  .page-about .about-tl__body p {
    padding-left: 0;
  }

  .page-about .about-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-next__item:nth-child(odd) {
    border-right: 3px solid var(--ink-2);
  }
}

/* ---------- 桌面双栏 ---------- */
@media (min-width: 1000px) {
  .page-about {
    padding-bottom: 120px;
  }

  .page-about .about-head {
    padding: 48px 0 68px;
  }

  .page-about .about-body {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 0 68px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 28px;
    align-self: start;
    padding-top: 68px;
    border-bottom: 0;
  }

  .page-about .about-rail__title {
    display: block;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-rail__link {
    display: flex;
    align-items: flex-start;
    width: 100%;
    padding: 12px 10px 12px 14px;
    font-size: 14px;
    background: transparent;
    border: 0;
    border-left: 3px solid transparent;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    color: var(--sand);
    background: var(--ink-2);
    border-left-color: var(--amber-lift);
  }

  .page-about .about-rail__num {
    display: block;
    margin-bottom: 4px;
  }

  .page-about .about-rail__link > span:last-child {
    display: block;
    white-space: normal;
    line-height: 1.4;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    margin-top: 44px;
  }

  .page-about .about-split--reverse .about-figure {
    margin-top: 0;
  }

  .page-about .about-figure--compact {
    margin-top: 0;
  }

  .page-about .about-stats--wide {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

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

  .page-about .about-next__item {
    border-right: 3px solid var(--ink-2);
  }

  .page-about .about-next__item:last-child {
    border-right: 0;
  }

  .page-about .about-next__link:hover,
  .page-about .about-next__link:focus-visible {
    padding-left: 12px;
  }
}

@media (min-width: 1280px) {
  .page-about .about-body {
    grid-template-columns: 232px minmax(0, 1fr);
    gap: 0 80px;
  }

  .page-about .about-stats--wide {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .page-about .about-stat__num {
    font-size: 54px;
  }
}

/* ---------- 减少动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow__node rect,
  .page-about .about-tl,
  .page-about .about-next__link,
  .page-about .about-rail__link,
  .page-about .about-crumb a {
    transition: none;
  }
}