.page-about {
  --about-card: rgba(18, 58, 102, 0.4);
  --about-ink-soft: rgba(8, 26, 47, 0.06);
  background: var(--night);
  color: var(--silver);
  padding-bottom: clamp(32px, 5vw, 72px);
  overflow-x: hidden;
}

.page-about [id^="chapter-"] {
  scroll-margin-top: 84px;
}

.page-about .about-crumbs {
  padding-top: clamp(14px, 2.4vw, 26px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(18px, 3.4vw, 40px) 0 clamp(28px, 5vw, 64px);
  background:
    radial-gradient(120% 90% at 8% 0%, rgba(0, 229, 255, 0.12), transparent 58%),
    radial-gradient(90% 80% at 96% 96%, rgba(255, 107, 26, 0.12), transparent 56%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
  align-items: end;
}

.page-about .about-hero__copy h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(32px, 6vw, 74px);
  line-height: 1.02;
  letter-spacing: -0.03em;
  color: var(--fog);
  max-width: 18em;
}

.page-about .about-hero__lede {
  margin: clamp(14px, 2vw, 22px) 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.5vw, 18px);
  line-height: 1.75;
  color: var(--silver);
}

.page-about .about-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .sk-chip--static {
  display: inline-flex;
  align-items: center;
  padding: 6px 14px;
  border: 1px solid var(--line-cyan);
  border-radius: var(--radius-pill);
  background: rgba(0, 229, 255, 0.06);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: linear-gradient(150deg, var(--steel), var(--pit));
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-hero__caption {
  position: absolute;
  left: 14px;
  bottom: 12px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  background: rgba(8, 26, 47, 0.72);
  color: var(--cyan);
  font-size: 11px;
  letter-spacing: 0.12em;
}

/* ---------- 长卷骨架与刻度导航 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
  align-items: start;
}

.page-about .about-rail {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 4px;
}

.page-about .about-rail__nav {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  padding: 4px 2px;
  scrollbar-width: thin;
}

.page-about .about-rail__label {
  display: none;
  color: var(--silver);
  font-size: 11px;
  letter-spacing: 0.14em;
  opacity: 0.7;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  flex: 0 0 auto;
  padding: 6px 12px 6px 8px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  color: var(--silver);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease), background 0.25s var(--ease);
}

.page-about .about-rail__tick {
  display: block;
  width: 3px;
  height: 14px;
  border-radius: 2px;
  background: var(--line-cyan);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--fog);
  border-color: var(--line-cyan);
  background: rgba(0, 229, 255, 0.08);
  outline: none;
}

.page-about .about-rail__link:hover .about-rail__tick,
.page-about .about-rail__link:focus-visible .about-rail__tick {
  background: var(--orange);
}

.page-about .about-rail__top {
  display: none;
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  border-radius: 50%;
  border: 1px solid var(--line-cyan);
  background: var(--slate);
  color: var(--cyan);
  font-size: 17px;
  line-height: 1;
  cursor: pointer;
  transition: background 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .about-rail__top:hover,
.page-about .about-rail__top:focus-visible {
  background: var(--cyan);
  color: var(--night);
  outline: none;
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  position: relative;
  margin-bottom: clamp(22px, 3.6vw, 44px);
  padding: clamp(22px, 3.4vw, 48px) clamp(18px, 3vw, 44px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line-soft);
  overflow: hidden;
}

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

.page-about .chapter--band {
  background: linear-gradient(135deg, rgba(18, 58, 102, 0.92), rgba(8, 26, 47, 0.97) 48%, rgba(30, 42, 56, 0.92));
}

.page-about .chapter--pit {
  background: linear-gradient(160deg, rgba(11, 15, 20, 0.96), rgba(8, 26, 47, 0.92));
}

.page-about .chapter--band::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(45deg, rgba(199, 208, 217, 0.05) 0 2px, transparent 2px 7px);
  opacity: 0.55;
}

.page-about .chapter--light {
  background: var(--fog);
  border-color: rgba(8, 26, 47, 0.12);
  color: var(--night);
}

.page-about .chapter__head {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: clamp(12px, 2vw, 24px);
  margin-bottom: clamp(16px, 2.4vw, 26px);
}

.page-about .chapter__num {
  font-family: var(--font-display);
  font-size: clamp(48px, 7vw, 92px);
  line-height: 0.82;
  letter-spacing: -0.04em;
  color: rgba(0, 229, 255, 0.18);
  -webkit-text-stroke: 1px rgba(0, 229, 255, 0.5);
}

.page-about .chapter--light .chapter__num {
  color: rgba(8, 26, 47, 0.08);
  -webkit-text-stroke: 1px rgba(18, 58, 102, 0.45);
}

.page-about .chapter__headtext {
  flex: 1 1 240px;
  min-width: 0;
}

.page-about .chapter--light .sk-eyebrow {
  color: var(--steel);
}

.page-about .chapter__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(25px, 3.4vw, 42px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--fog);
}

.page-about .chapter--light .chapter__title {
  color: var(--night);
}

.page-about .chapter__body {
  position: relative;
  max-width: 72ch;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.78;
}

.page-about .chapter__body p {
  margin: 0 0 0.9em;
}

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

.page-about .chapter--light .chapter__body {
  color: rgba(8, 26, 47, 0.82);
}

.page-about .chapter__split {
  display: grid;
  gap: clamp(16px, 2.6vw, 30px);
  margin-bottom: clamp(16px, 2.6vw, 28px);
}

/* ---------- 三主线 ---------- */
.page-about .pillar-list {
  position: relative;
  display: grid;
  gap: 10px;
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .pillar {
  padding: 14px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line-soft);
  background: rgba(11, 15, 20, 0.45);
}

.page-about .pillar__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .pillar__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--silver);
}

/* ---------- 双轨 ---------- */
.page-about .track-grid {
  position: relative;
  display: grid;
  gap: 12px;
  margin-top: clamp(16px, 2.4vw, 26px);
}

.page-about .track {
  padding: clamp(16px, 2.2vw, 26px);
  border-radius: var(--radius-md);
  border: 1px solid var(--line-soft);
  background: linear-gradient(170deg, rgba(30, 42, 56, 0.92), rgba(11, 15, 20, 0.86));
}

.page-about .track__idx {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .track__title {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-size: clamp(20px, 2.4vw, 27px);
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .track__text {
  margin: 0 0 12px;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--silver);
}

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

.page-about .track__list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(199, 208, 217, 0.86);
}

.page-about .track__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

/* ---------- 团队 ---------- */
.page-about .team-figure {
  margin: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--pit);
}

.page-about .team-figure img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .team-filter {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 clamp(14px, 2vw, 22px);
}

.page-about .team-grid {
  position: relative;
  display: grid;
  gap: 12px;
}

.page-about .team-card {
  padding: clamp(14px, 2vw, 20px);
  border-radius: var(--radius-md);
  border: 1px solid var(--line-soft);
  background: rgba(30, 42, 56, 0.86);
  cursor: default;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .team-card:hover,
.page-about .team-card:focus {
  border-color: var(--line-cyan);
  background: rgba(30, 42, 56, 1);
  transform: translateY(-3px);
  outline: none;
}

.page-about .team-card:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .team-card__count {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange);
}

.page-about .team-card__count span {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 400;
  margin-left: 4px;
  color: var(--silver);
}

.page-about .team-card__role {
  margin: 8px 0 6px;
  font-family: var(--font-display);
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .team-card__line {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.6;
  color: rgba(199, 208, 217, 0.82);
}

.page-about .team-card__more {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height 0.35s var(--ease), opacity 0.3s var(--ease), margin-top 0.3s var(--ease);
}

.page-about .team-card__more p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.68;
  color: var(--cyan);
}

.page-about .team-card:hover .team-card__more,
.page-about .team-card:focus .team-card__more {
  max-height: 220px;
  opacity: 1;
  margin-top: 10px;
}

.page-about [data-filter-item][hidden] {
  display: none;
}

.page-about .sk-empty {
  grid-column: 1 / -1;
  margin: 0;
  padding: 16px;
  border: 1px dashed var(--line-cyan);
  border-radius: var(--radius-md);
  color: var(--silver);
  font-size: 14px;
}

/* ---------- 同步与巡检 ---------- */
.page-about .metric-grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: clamp(16px, 2.4vw, 24px) 0 clamp(18px, 2.8vw, 30px);
}

.page-about .metric {
  padding: 12px 14px;
  border-left: 3px solid var(--orange);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: rgba(11, 15, 20, 0.55);
}

.page-about .metric__value {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 4.4vw, 50px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--fog);
}

.page-about .metric__label {
  margin: 6px 0 0;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--silver);
}

.page-about .sync-split {
  position: relative;
  display: grid;
  gap: clamp(16px, 2.6vw, 28px);
}

.page-about .sync-log {
  margin: 0;
  padding: 0 0 0 16px;
  list-style: none;
  border-left: 1px solid var(--line-cyan);
  display: grid;
  gap: 16px;
}

.page-about .sync-log li {
  position: relative;
}

.page-about .sync-log li::before {
  content: "";
  position: absolute;
  left: -21px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 3px rgba(255, 107, 26, 0.18);
}

.page-about .sync-log__tag {
  margin: 0 0 5px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .sync-log__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--silver);
}

.page-about .sync-figure {
  margin: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--pit);
  order: -1;
}

.page-about .sync-figure img {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

/* ---------- 回访设计 ---------- */
.page-about .return-list {
  display: grid;
  gap: 8px;
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .return-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px 14px;
  border-radius: var(--radius-pill);
  background: var(--about-ink-soft);
  border: 1px solid rgba(8, 26, 47, 0.1);
}

.page-about .return-list__key {
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .return-list__text {
  font-size: 14.5px;
  line-height: 1.6;
  color: rgba(8, 26, 47, 0.86);
}

.page-about .return-note {
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: rgba(8, 26, 47, 0.78);
}

.page-about .return-note a {
  color: var(--steel);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .return-note a:hover,
.page-about .return-note a:focus-visible {
  color: var(--orange);
  outline: none;
  text-decoration-thickness: 2px;
}

/* ---------- 下一站 ---------- */
.page-about .about-next {
  padding: clamp(28px, 4.6vw, 60px) 0 0;
}

.page-about .about-next__title {
  margin: 0 0 clamp(14px, 2vw, 22px);
  font-family: var(--font-display);
  font-size: clamp(24px, 3.2vw, 38px);
  letter-spacing: -0.02em;
  color: var(--fog);
}

.page-about .about-next__grid {
  display: grid;
  gap: 10px;
}

.page-about .about-next__card {
  position: relative;
  display: block;
  padding: 16px 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line-soft);
  background: linear-gradient(150deg, rgba(18, 58, 102, 0.5), rgba(11, 15, 20, 0.7));
  text-decoration: none;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}

.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  border-color: var(--cyan);
  transform: translateY(-3px);
  outline: none;
}

.page-about .about-next__card-eyebrow {
  display: block;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .about-next__card-title {
  display: block;
  margin: 6px 0 6px;
  font-family: var(--font-display);
  font-size: 20px;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .about-next__card-text {
  display: block;
  font-size: 13.5px;
  line-height: 1.6;
  color: rgba(199, 208, 217, 0.84);
}

/* ---------- 响应式 ---------- */
@media (min-width: 680px) {
  .page-about .pillar-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
  }

  .page-about .about-body {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: clamp(24px, 3.4vw, 52px);
  }

  .page-about .about-rail {
    flex-direction: column;
    align-items: stretch;
    gap: 14px;
    position: sticky;
    top: clamp(24px, 8vh, 80px);
    padding: 18px 0;
    border-top: 1px solid var(--line-cyan);
  }

  .page-about .about-rail__nav {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    overflow: visible;
  }

  .page-about .about-rail__label {
    display: block;
    margin: 0 0 6px;
  }

  .page-about .about-rail__link {
    border-radius: var(--radius-md);
    white-space: normal;
  }

  .page-about .about-rail__top {
    display: block;
    align-self: flex-start;
  }

  .page-about .chapter__split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .sync-split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }

  .page-about .sync-figure {
    order: 0;
  }

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

@media (hover: none) {
  .page-about .team-card__more {
    max-height: none;
    opacity: 1;
    margin-top: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .about-next__card,
  .page-about .about-rail__top,
  .page-about .about-rail__link {
    transition: none;
  }

  .page-about .team-card:hover,
  .page-about .team-card:focus,
  .page-about .about-next__card:hover,
  .page-about .about-next__card:focus-visible {
    transform: none;
  }
}