.page-about {
  --about-rail-w: 132px;
  --about-measure: 66ch;
}

/* ---------- 面包屑与首屏 ---------- */
.page-about .breadcrumb {
  margin-top: clamp(18px, 3vw, 28px);
}

.page-about .about-hero {
  padding-block: clamp(30px, 5vw, 72px) clamp(26px, 4vw, 52px);
  border-top: 1px solid var(--line-graphite);
  border-bottom: 1px solid var(--line-graphite);
  margin-top: clamp(16px, 2.4vw, 28px);
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  max-width: 20ch;
  font-family: var(--font-head);
  font-size: clamp(34px, 6.4vw, 72px);
  font-weight: 200;
  line-height: 1.08;
  letter-spacing: -0.015em;
  color: var(--text-on-dark);
}

.page-about .about-hero__lead {
  margin: clamp(18px, 2.6vw, 30px) 0 0;
  max-width: var(--about-measure);
  font-size: clamp(15px, 1.2vw, 17px);
  line-height: 1.68;
  color: var(--text-on-dark);
  opacity: 0.82;
}

.page-about .hero-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(24px, 5vw, 76px);
  margin-top: clamp(26px, 4vw, 46px);
}

.page-about .hero-metric {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .hero-metric__value {
  font-family: var(--font-mono);
  font-size: clamp(42px, 5.6vw, 68px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--cyan-signal);
  border-bottom: 1px solid var(--cyan-signal);
  padding-bottom: 8px;
  font-variant-numeric: tabular-nums;
}

.page-about .hero-metric__unit {
  font-size: 0.38em;
  margin-left: 2px;
  color: var(--cyan-deep);
}

.page-about .hero-metric__label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--paper-mute);
  letter-spacing: 0.02em;
}

/* ---------- 双栏骨架：正文 + 右侧档案轨 ---------- */
.page-about .dossier {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin-top: clamp(24px, 3.4vw, 44px);
}

.page-about .dossier__rail {
  order: -1;
  margin-bottom: clamp(16px, 2.4vw, 24px);
}

.page-about .rail-list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .rail-list__item {
  flex: 0 0 auto;
}

.page-about .rail-list__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-on-dark);
  text-decoration: none;
  border: 1px solid var(--line-graphite);
  border-radius: var(--radius);
  white-space: nowrap;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .rail-list__num {
  font-size: 11px;
  color: var(--cyan-deep);
}

.page-about .rail-list__link:hover,
.page-about .rail-list__link:focus-visible {
  border-color: var(--cyan-signal);
  color: var(--cyan-signal);
  background-color: rgba(55, 245, 200, 0.06);
}

.page-about .rail-list__link:hover .rail-list__num,
.page-about .rail-list__link:focus-visible .rail-list__num {
  color: var(--cyan-signal);
}

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

/* ---------- 章节通用 ---------- */
.page-about .chapter {
  padding-block: clamp(40px, 6vw, 78px);
  border-top: 1px solid var(--line-graphite);
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: clamp(8px, 1.6vw, 20px);
}

.page-about .chapter__head {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 16px;
  margin-bottom: clamp(24px, 3.4vw, 44px);
}

.page-about .chapter__index {
  padding-left: 12px;
  border-left: 2px solid var(--cyan-signal);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--cyan-signal);
  line-height: 1.6;
}

.page-about .chapter__title {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(24px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--text-on-dark);
}

.page-about .chapter__note {
  margin: 12px 0 0;
  max-width: var(--about-measure);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-on-dark);
  opacity: 0.72;
}

.page-about .chapter__foot {
  margin: clamp(20px, 2.8vw, 30px) 0 0;
  max-width: var(--about-measure);
  font-size: 14px;
  line-height: 1.7;
}

.page-about .inline-link {
  color: var(--cyan-signal);
  text-decoration: none;
  border-bottom: 1px solid rgba(55, 245, 200, 0.45);
  padding-bottom: 1px;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

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

/* ---------- 横向主题带 ---------- */
.page-about .quote-band {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  min-height: 108px;
  padding-block: clamp(24px, 3.4vw, 34px);
  margin-block: clamp(12px, 2vw, 24px);
  border-top: 1px solid var(--line-graphite);
  border-bottom: 1px solid var(--line-graphite);
}

.page-about .quote-band__index {
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan-deep);
}

.page-about .quote-band__text {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(20px, 3.2vw, 36px);
  font-weight: 200;
  line-height: 1.34;
  letter-spacing: 0.01em;
  color: var(--text-on-dark);
}

/* ---------- 01 日常业务 ---------- */
.page-about .duty-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .duty {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  column-gap: 16px;
  padding-block: clamp(18px, 2.4vw, 26px);
  border-bottom: 1px solid var(--line-graphite);
}

.page-about .duty:first-child {
  border-top: 1px solid var(--line-graphite);
}

.page-about .duty__num {
  grid-column: 1;
  grid-row: 1;
  align-self: start;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--cyan-deep);
  padding-top: 5px;
}

.page-about .duty__title {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-size: clamp(18px, 2vw, 21px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text-on-dark);
}

.page-about .duty__text {
  grid-column: 2;
  grid-row: 2;
  margin: 8px 0 0;
  max-width: var(--about-measure);
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--text-on-dark);
  opacity: 0.78;
}

.page-about .duty__out {
  grid-column: 2;
  grid-row: 3;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin: 12px 0 0;
  font-size: 13px;
  color: var(--paper-mute);
}

/* ---------- 02 校订四步 ---------- */
.page-about .figure--review {
  margin: 0 0 clamp(26px, 3.6vw, 42px);
  aspect-ratio: 14 / 9;
}

.page-about .steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .step {
  position: relative;
  padding: 20px 20px 20px 24px;
  background-color: var(--deep-pitch);
  border: 2px solid var(--line-graphite);
  border-left: 4px solid var(--cyan-deep);
  border-radius: var(--radius);
  transition: border-color 0.25s var(--ease), background-color 0.25s var(--ease);
}

.page-about .step:hover {
  border-color: var(--cyan-signal);
  background-color: var(--pitch-layer);
}

.page-about .step__num {
  display: block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--cyan-signal);
}

.page-about .step__title {
  margin: 8px 0 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-on-dark);
}

.page-about .step__text {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-on-dark);
  opacity: 0.76;
}

.page-about .step__time {
  display: inline-block;
  margin-top: 14px;
  padding: 4px 10px;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--amber-tick);
  border: 1px solid rgba(255, 176, 32, 0.42);
  border-radius: var(--radius);
}

/* ---------- 03 时间线 ---------- */
.page-about .timeline {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline__item {
  position: relative;
  padding: 18px 0 18px 28px;
  border-left: 1px solid var(--line-graphite);
}

.page-about .timeline__item:first-child {
  padding-top: 6px;
}

.page-about .timeline__item:last-child {
  padding-bottom: 6px;
}

.page-about .timeline__tick {
  position: absolute;
  left: -5px;
  top: 24px;
  width: 9px;
  height: 9px;
  background-color: var(--cyan-signal);
  transition: background-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .timeline__item:first-child .timeline__tick {
  top: 12px;
}

.page-about .timeline__item:hover .timeline__tick {
  background-color: var(--signal-orange);
  transform: scale(1.25);
}

.page-about .timeline__era {
  display: block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--cyan-signal);
}

.page-about .timeline__text {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-on-dark);
  opacity: 0.78;
}

.page-about .years-side {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 32px);
  margin-top: clamp(30px, 4vw, 52px);
  padding-top: clamp(24px, 3vw, 36px);
  border-top: 1px solid var(--line-graphite);
}

.page-about .figure--city {
  margin: 0;
  aspect-ratio: 3 / 2;
}

.page-about .years-side__title {
  margin: 0;
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-on-dark);
}

.page-about .years-side__text p {
  margin: 12px 0 0;
  max-width: var(--about-measure);
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--text-on-dark);
  opacity: 0.78;
}

/* ---------- 04 团队 ---------- */
.page-about .crew {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .crew__card {
  padding: 22px 22px 18px;
  background-color: var(--pitch-layer);
  border: 2px solid var(--line-graphite);
  border-radius: var(--radius);
  box-shadow: 6px 6px 0 rgba(6, 21, 18, 0.5);
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.page-about .crew__card:hover {
  transform: translate(-3px, -3px);
  border-color: var(--cyan-signal);
  box-shadow: 9px 9px 0 rgba(6, 21, 18, 0.55);
}

.page-about .crew__tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--ink-night);
  background-color: var(--cyan-signal);
  padding: 2px 8px;
  border-radius: var(--radius);
}

.page-about .crew__role {
  margin: 12px 0 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-on-dark);
}

.page-about .crew__duty {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-on-dark);
  opacity: 0.78;
}

.page-about .crew__with {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line-graphite);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--cyan-deep);
}

.page-about .observer {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: clamp(26px, 3.4vw, 40px);
  padding: clamp(20px, 2.8vw, 30px);
  border: 2px solid var(--line-graphite);
  border-radius: var(--radius);
  background-color: var(--deep-pitch);
}

.page-about .observer__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(48px, 7vw, 84px);
  font-weight: 600;
  line-height: 0.95;
  letter-spacing: -0.04em;
  color: var(--cyan-signal);
  font-variant-numeric: tabular-nums;
}

.page-about .observer__text {
  margin: 0;
  max-width: var(--about-measure);
  font-size: 14.5px;
  line-height: 1.74;
  color: var(--text-on-dark);
  opacity: 0.8;
}

/* ---------- 05 协作生态 ---------- */
.page-about .network {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .network__row {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  column-gap: 18px;
  padding-block: clamp(18px, 2.4vw, 26px);
  border-bottom: 1px solid var(--line-graphite);
}

.page-about .network__row:first-child {
  border-top: 1px solid var(--line-graphite);
}

.page-about .network__count {
  font-size: clamp(28px, 3.6vw, 40px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--signal-orange);
  font-variant-numeric: tabular-nums;
}

.page-about .network__name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-on-dark);
}

.page-about .network__text {
  margin: 8px 0 0;
  max-width: var(--about-measure);
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-on-dark);
  opacity: 0.76;
}

/* ---------- 06 长期做法 ---------- */
.page-about .creed {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
}

.page-about .creed__item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  column-gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line-graphite);
}

.page-about .creed__item:first-child {
  border-top: 1px solid var(--line-graphite);
}

.page-about .creed__num {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--cyan-deep);
  padding-top: 5px;
}

.page-about .creed__title {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-on-dark);
}

.page-about .creed__text {
  margin: 8px 0 0;
  max-width: var(--about-measure);
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-on-dark);
  opacity: 0.78;
}

/* ---------- 07 年度回顾 ---------- */
.page-about .annual {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 36px);
}

.page-about .annual__body p {
  margin: 0 0 14px;
  max-width: var(--about-measure);
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--text-on-dark);
  opacity: 0.8;
}

.page-about .annual__link {
  margin-bottom: 0;
}

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

/* ---------- 图片基础保障 ---------- */
.page-about img {
  max-width: 100%;
  height: auto;
}

.page-about .media {
  width: 100%;
}

.page-about .media__img {
  object-fit: cover;
}

/* ---------- 窄屏修正 ---------- */
@media (max-width: 560px) {
  .page-about .chapter__head {
    grid-template-columns: 40px minmax(0, 1fr);
    gap: 12px;
  }

  .page-about .chapter__index {
    padding-left: 8px;
    font-size: 12px;
  }

  .page-about .duty,
  .page-about .creed__item {
    grid-template-columns: 32px minmax(0, 1fr);
    column-gap: 12px;
  }

  .page-about .network__row {
    grid-template-columns: 46px minmax(0, 1fr);
    column-gap: 14px;
  }

  .page-about .crew__card {
    box-shadow: 4px 4px 0 rgba(6, 21, 18, 0.5);
  }
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 720px) {
  .page-about .quote-band {
    flex-direction: row;
    align-items: center;
    gap: 28px;
  }

  .page-about .quote-band__index {
    flex: 0 0 auto;
    padding-top: 0;
  }

  .page-about .steps,
  .page-about .crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .observer {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: 28px;
  }
}

@media (min-width: 900px) {
  .page-about .years-side {
    grid-template-columns: 320px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .annual {
    grid-template-columns: minmax(0, 1fr) 300px;
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .timeline {
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    column-gap: 18px;
  }

  .page-about .timeline__item,
  .page-about .timeline__item:first-child,
  .page-about .timeline__item:last-child {
    padding: 30px 16px 0 0;
    border-left: 0;
    border-top: 1px solid var(--line-graphite);
  }

  .page-about .timeline__tick,
  .page-about .timeline__item:first-child .timeline__tick {
    left: 0;
    top: -5px;
  }

  .page-about .timeline__text {
    font-size: 13px;
    line-height: 1.66;
  }
}

@media (min-width: 1080px) {
  .page-about .dossier {
    grid-template-columns: minmax(0, 1fr) var(--about-rail-w);
    column-gap: clamp(40px, 4vw, 64px);
    align-items: start;
  }

  .page-about .dossier__rail {
    order: 0;
    grid-column: 2;
    grid-row: 1;
    position: sticky;
    top: calc(var(--frame-h) + 32px);
    margin-bottom: 0;
  }

  .page-about .dossier__body {
    grid-column: 1;
    grid-row: 1;
  }

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

  .page-about .rail-list__link {
    border: 0;
    border-left: 2px solid var(--line-graphite);
    border-radius: 0;
    padding: 10px 4px 10px 12px;
    width: 100%;
  }

  .page-about .rail-list__link:hover,
  .page-about .rail-list__link:focus-visible {
    border-left-color: var(--signal-orange);
    background-color: rgba(55, 245, 200, 0.05);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .crew__card,
  .page-about .step,
  .page-about .rail-list__link,
  .page-about .timeline__tick {
    transition: none;
  }

  .page-about .crew__card:hover {
    transform: none;
  }
}