.page-about {
  --about-gap: clamp(20px, 3.4vw, 40px);
  --about-edge: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  display: block;
}

/* ---------- 面包屑留白 ---------- */
.page-about .breadcrumb {
  padding-block: 18px 2px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(20px, 3.6vw, 40px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-hero__body h1 {
  margin: 10px 0 16px;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 14px;
}

.page-about .about-hero__stats li {
  position: relative;
  padding: 12px 12px 12px 16px;
  background: linear-gradient(180deg, rgba(19, 42, 82, .72), rgba(10, 22, 51, .5));
  border: 1px solid var(--line-soft);
  clip-path: var(--about-edge);
}

.page-about .about-hero__stats li::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--cyan);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(28px, 5.2vw, 40px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .stat-plus {
  color: var(--amber);
}

.page-about .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

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

/* ---------- 起步与主张 ---------- */
.page-about .about-origin__grid {
  display: grid;
  gap: clamp(16px, 2.6vw, 30px);
}

.page-about .about-origin__head h2 {
  margin: 10px 0 0;
}

.page-about .about-origin__copy p {
  margin: 0 0 16px;
}

.page-about .about-origin__copy p:last-of-type {
  margin-bottom: 0;
}

.page-about .about-origin__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

/* ---------- 发展历程 ---------- */
.page-about .about-history__head h2 {
  margin: 10px 0 0;
  max-width: 22em;
}

.page-about .about-history__strip {
  margin: clamp(20px, 3.4vw, 34px) 0 clamp(24px, 4vw, 40px);
}

.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 32px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 12px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--line) 22%, var(--line) 76%, rgba(30, 58, 107, 0) 100%);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 18px;
}

.page-about .timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 12px;
  width: 19px;
  height: 19px;
  background: var(--ink-900);
  border: 1px solid var(--cyan);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
  z-index: 1;
  transition: background .3s var(--ease), border-color .3s var(--ease);
}

.page-about .timeline__item:hover::before {
  background: var(--amber);
  border-color: var(--amber);
}

.page-about .tl-card {
  position: relative;
  padding: 16px 18px;
  background: linear-gradient(160deg, rgba(19, 42, 82, .92), rgba(10, 22, 51, .86));
  border: 1px solid var(--line-soft);
  clip-path: var(--about-edge);
  transition: transform .32s var(--ease), border-color .32s var(--ease);
}

.page-about .tl-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--line-soft);
  transition: background .3s var(--ease);
}

.page-about .tl-card:hover,
.page-about .tl-card:focus-within {
  transform: translateY(-3px);
  border-color: rgba(127, 219, 255, .42);
}

.page-about .tl-card:hover::before,
.page-about .tl-card:focus-within::before {
  background: var(--amber);
}

.page-about .tl-card__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 12px;
  margin-bottom: 8px;
}

.page-about .tl-card__year {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--cyan);
  padding: 2px 8px;
  border: 1px solid rgba(0, 229, 255, .34);
  border-radius: var(--radius-pill);
}

.page-about .tl-card__head h3 {
  margin: 0;
  font-size: 17px;
  line-height: 1.35;
  letter-spacing: 0;
}

.page-about .tl-card p {
  margin: 0;
  font-size: 15px;
  color: var(--muted);
}

.page-about .tl-card__more {
  margin-top: 10px;
}

.page-about .tl-card__more p {
  padding-top: 10px;
  border-top: 1px dashed var(--line-soft);
  font-size: 14px;
  color: var(--cyan-mist);
}

.page-about .about-history__foot {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  font-size: 15px;
  color: var(--muted);
}

.page-about .about-history__foot a,
.page-about .about-team__foot a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 229, 255, .38);
}

.page-about .about-history__foot a:hover,
.page-about .about-team__foot a:hover {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

/* ---------- 服务原则 ---------- */
.page-about .about-principles__head h2 {
  margin: 10px 0 0;
}

.page-about .about-principles__lede {
  max-width: 46em;
  margin: 14px 0 0;
}

.page-about .principles-grid {
  margin-top: clamp(22px, 3.6vw, 38px);
  display: grid;
  gap: 14px;
}

.page-about .principle-card {
  position: relative;
  padding: 18px 18px 20px;
  background: rgba(10, 42, 51, .38);
  border: 1px solid var(--line-soft);
  clip-path: var(--about-edge);
  transition: transform .32s var(--ease), background .32s var(--ease);
  overflow: hidden;
}

.page-about .principle-card__bar {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), rgba(0, 229, 255, 0));
  transform: scaleX(.28);
  transform-origin: left;
  transition: transform .42s var(--ease);
}

.page-about .principle-card:hover,
.page-about .principle-card:focus-within {
  transform: translateY(-3px);
  background: rgba(19, 42, 82, .78);
}

.page-about .principle-card:hover .principle-card__bar,
.page-about .principle-card:focus-within .principle-card__bar {
  transform: scaleX(1);
  background: linear-gradient(90deg, var(--amber), rgba(255, 179, 0, 0));
}

.page-about .principle-card__idx {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .principle-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.page-about .principle-card p {
  margin: 0;
  font-size: 15px;
  color: var(--muted);
}

/* ---------- 团队与协作 ---------- */
.page-about .about-team__grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-team__head h2 {
  margin: 10px 0 12px;
  max-width: 20em;
}

.page-about .about-team__head p {
  margin: 0;
  color: var(--muted);
}

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

.page-about .team-cards {
  display: grid;
  gap: 14px;
}

.page-about .team-card {
  position: relative;
  padding: 18px;
  background: linear-gradient(200deg, rgba(19, 42, 82, .9), rgba(10, 22, 51, .8));
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--line-soft);
  clip-path: var(--about-edge);
  transition: transform .32s var(--ease), border-left-color .32s var(--ease);
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  transform: translateY(-3px);
  border-left-color: var(--cyan);
}

.page-about .team-card__idx {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--amber);
  margin-bottom: 8px;
}

.page-about .team-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.page-about .team-card p {
  margin: 0 0 10px;
  font-size: 15px;
  color: var(--muted);
}

.page-about .team-card__detail {
  margin: 0;
  padding-top: 10px;
  border-top: 1px dashed var(--line-soft);
  font-size: 14px;
  color: var(--cyan-mist);
}

.page-about .about-team__foot {
  margin: clamp(20px, 3vw, 30px) 0 0;
  font-size: 15px;
  color: var(--muted);
}

/* ---------- 覆盖与积累 ---------- */
.page-about .about-reach__head h2 {
  margin: 10px 0 0;
}

.page-about .reach-board {
  margin-top: clamp(22px, 3.6vw, 38px);
  display: grid;
  gap: 12px;
}

.page-about .reach-cell {
  position: relative;
  padding: 18px 18px 20px;
  background: rgba(19, 42, 82, .58);
  border: 1px solid var(--line-soft);
  clip-path: var(--about-edge);
  transition: background .32s var(--ease);
}

.page-about .reach-cell:hover {
  background: rgba(30, 58, 107, .68);
}

.page-about .reach-cell__label {
  display: block;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .reach-cell__num {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(22px, 3.4vw, 30px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--paper);
  margin-bottom: 10px;
}

.page-about .reach-cell--wide .reach-cell__num {
  font-size: clamp(20px, 2.8vw, 26px);
}

.page-about .reach-cell__plus {
  color: var(--amber);
}

.page-about .reach-cell p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

.page-about .about-reach__cta {
  margin-top: clamp(22px, 3.4vw, 36px);
  padding: clamp(20px, 3vw, 30px);
  background: linear-gradient(120deg, rgba(255, 179, 0, .12), rgba(0, 229, 255, .08) 60%, rgba(10, 22, 51, .2));
  border: 1px solid var(--line-soft);
  clip-path: var(--about-edge);
  display: grid;
  gap: 18px;
}

.page-about .about-reach__cta h3 {
  margin: 0 0 8px;
  font-size: 20px;
}

.page-about .about-reach__cta p {
  margin: 0;
  font-size: 15px;
  color: var(--muted);
}

.page-about .about-reach__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 键盘焦点 ---------- */
.page-about .tl-card:focus-visible,
.page-about .principle-card:focus-visible,
.page-about .team-card:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--ink-900), 0 0 0 4px var(--cyan), 0 0 18px rgba(0, 229, 255, .5);
}

/* ---------- 响应式：平板与桌面 ---------- */
@media (min-width: 700px) {
  .page-about .principles-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .reach-cell--wide {
    grid-column: 1 / -1;
  }

  .page-about .about-reach__cta {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .about-reach__actions {
    justify-content: flex-end;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: center;
  }

  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    align-items: start;
  }

  .page-about .about-origin__head {
    position: sticky;
    top: 96px;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 4fr) minmax(0, 3fr);
    align-items: start;
  }

  .page-about .about-team__head {
    grid-column: 1 / -1;
  }

  .page-about .team-cards {
    grid-template-columns: 1fr;
  }

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

  .page-about .reach-cell--wide {
    grid-column: span 2;
    grid-row: span 2;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  /* 桌面端：时间线节点悬停展开补充说明 */
  .page-about .tl-card__more {
    max-height: 0;
    margin-top: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height .4s var(--ease), opacity .3s var(--ease), margin-top .3s var(--ease);
  }

  .page-about .tl-card:hover .tl-card__more,
  .page-about .tl-card:focus-within .tl-card__more,
  .page-about .tl-card:focus-visible .tl-card__more {
    max-height: 260px;
    margin-top: 10px;
    opacity: 1;
  }
}

@media (min-width: 1180px) {
  .page-about .principles-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 5fr) minmax(0, 3fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-card,
  .page-about .principle-card,
  .page-about .team-card,
  .page-about .principle-card__bar,
  .page-about .reach-cell {
    transition: none;
  }

  .page-about .tl-card:hover,
  .page-about .principle-card:hover,
  .page-about .team-card:hover {
    transform: none;
  }
}