.page-about {
  --about-rule: rgba(60, 90, 115, 0.2);
  --about-rule-inverse: rgba(143, 182, 188, 0.32);
  --about-shell: 1240px;
  display: block;
  background: var(--c-paper);
  color: var(--c-ink);
  font-family: var(--f-body);
  overflow-x: hidden;
}

.page-about .shell {
  width: 100%;
  max-width: var(--about-shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  background: var(--c-deep);
  color: var(--c-paper);
  padding: clamp(1.4rem, 3vw, 2rem) 0 clamp(2.6rem, 6vw, 4.2rem);
  position: relative;
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -8%;
  top: 18%;
  width: min(46vw, 460px);
  aspect-ratio: 1 / 1;
  border-radius: 42% 58% 55% 45% / 48% 42% 58% 52%;
  background: radial-gradient(circle at 35% 35%, rgba(44, 107, 116, 0.5), rgba(14, 42, 34, 0) 68%);
  pointer-events: none;
}

.page-about .about-hero .breadcrumb {
  position: relative;
  z-index: 1;
  color: var(--c-steel-soft);
}

.page-about .about-hero .breadcrumb a {
  color: var(--c-steel-soft);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb a:hover {
  color: var(--c-amber-pale);
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.6rem, 4vw, 2.6rem);
  margin-top: clamp(1.5rem, 3.5vw, 2.4rem);
}

.page-about .about-hero__lead .eyebrow {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-steel-soft);
  margin: 0 0 0.9rem;
}

.page-about h1 {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(2rem, 7.2vw, 4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 1.1rem;
  color: var(--c-paper);
  max-width: 18ch;
}

.page-about .about-hero__lead .lede {
  font-size: clamp(1rem, 2.4vw, 1.125rem);
  line-height: 1.8;
  color: rgba(244, 241, 232, 0.82);
  max-width: 40ch;
  margin: 0;
}

.page-about .about-hero__stats {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-rule-inverse);
  border: 1px solid var(--about-rule-inverse);
  align-self: end;
}

.page-about .about-hero__stats > div {
  background: var(--c-deep);
  padding: 0.95rem 1rem 1.05rem;
}

.page-about .about-hero__stats dt {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-steel-soft);
  margin-bottom: 0.5rem;
}

.page-about .about-hero__stats dd {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 0.2rem;
}

.page-about .stat-num {
  font-family: var(--f-mono);
  font-weight: 600;
  font-size: clamp(1.5rem, 4.4vw, 1.95rem);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--c-amber);
}

.page-about .stat-unit {
  font-size: 0.8125rem;
  color: var(--c-steel-soft);
}

/* ---------- 目录条 ---------- */
.page-about .toc-rail {
  display: flex;
  gap: 0.45rem;
  overflow-x: auto;
  scrollbar-width: none;
  padding-block: 0.85rem;
  border-bottom: 1px solid var(--about-rule);
  background: var(--c-paper);
}

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

.page-about .toc-rail a {
  flex: 0 0 auto;
  font-size: 13px;
  line-height: 1;
  padding: 0.42rem 0.72rem;
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--c-mono);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .toc-rail a:hover,
.page-about .toc-rail a:focus-visible {
  border-color: var(--c-steel-soft);
  color: var(--c-deep);
}

.page-about .toc-rail a.is-active {
  background: var(--c-amber-pale);
  border-color: var(--c-amber);
  color: var(--c-deep);
  font-weight: 600;
}

/* ---------- 通用区块骨架 ---------- */
.page-about .about-section {
  padding-block: clamp(2.4rem, 6vw, 4.6rem);
}

.page-about .about-section--lines {
  background: var(--c-paper-2);
}

.page-about .about-block {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1rem, 3vw, 2rem);
}

.page-about .about-block__aside {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
}

.page-about .aside-num {
  font-family: var(--f-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--c-amber);
  letter-spacing: 0.08em;
  border-bottom: 2px solid var(--c-amber);
  padding-bottom: 0.1rem;
}

.page-about .aside-label {
  font-family: var(--f-editorial);
  font-size: 0.9375rem;
  letter-spacing: 0.06em;
  color: var(--c-steel);
}

.page-about .section-title {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 4.2vw, 2.4rem);
  line-height: 1.15;
  letter-spacing: -0.015em;
  margin: 0 0 1rem;
  color: var(--c-deep);
}

.page-about .section-title--inverse {
  color: var(--c-paper);
}

.page-about .prose {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--c-ink);
  max-width: 40ch;
  margin: 0 0 1.1rem;
}

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

.page-about .prose a:hover {
  color: var(--c-amber);
}

.page-about .prose--inverse {
  color: rgba(244, 241, 232, 0.82);
}

/* ---------- 图表容器 ---------- */
.page-about .figure-frame {
  margin: 1.6rem 0 0;
}

.page-about .figure-frame img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  background: var(--c-paper-2);
}

.page-about .figure-frame--wide img {
  aspect-ratio: 3 / 2;
}

.page-about .figure-frame__tag {
  display: block;
  margin-top: 0.6rem;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--c-mono);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: clamp(1.6rem, 3.5vw, 2.4rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.4rem;
}

.page-about .timeline__item {
  position: relative;
  padding-left: 1.35rem;
  border-left: 1px solid var(--c-steel-soft);
}

.page-about .timeline__year {
  display: block;
  font-family: var(--f-mono);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--c-mono);
  margin-bottom: 0.45rem;
}

.page-about .timeline__dot {
  display: none;
}

.page-about .timeline__title {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.35;
  margin: 0 0 0.4rem;
  color: var(--c-deep);
}

.page-about .timeline__item p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(32, 40, 42, 0.78);
  max-width: 42ch;
}

.page-about .timeline__item.is-current .timeline__year {
  color: var(--c-amber);
}

/* ---------- 业务线 ---------- */
.page-about .lines {
  list-style: none;
  margin: clamp(1.4rem, 3vw, 2rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.6rem;
}

.page-about .line {
  position: relative;
  padding-top: 1.1rem;
  border-top: 2px solid var(--c-deep);
}

.page-about .line:nth-child(2) {
  border-top-color: var(--c-steel);
}

.page-about .line:nth-child(3) {
  border-top-color: var(--c-amber);
}

.page-about .line__idx {
  display: block;
  font-family: var(--f-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--c-mono);
  margin-bottom: 0.55rem;
}

.page-about .line__title {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: 1.25rem;
  line-height: 1.3;
  margin: 0 0 0.6rem;
  color: var(--c-deep);
}

.page-about .line p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(32, 40, 42, 0.82);
}

.page-about .line p a {
  color: var(--c-steel);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .line p a:hover {
  color: var(--c-amber);
}

/* ---------- 覆盖与规模 ---------- */
.page-about .about-section--scale {
  background: var(--c-deep-2);
  color: var(--c-paper);
}

.page-about .about-block__aside--inverse .aside-label {
  color: var(--c-steel-soft);
}

.page-about .scale-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(0.9rem, 2.5vw, 1.6rem);
}

.page-about .scale-figure {
  margin-top: clamp(1.6rem, 3vw, 2.2rem);
}

.page-about .scale-figure img {
  filter: saturate(0.85);
}

.page-about .scale-figure .figure-frame__tag {
  color: var(--c-steel-soft);
}

.page-about .scale-facts {
  margin: clamp(1.6rem, 3.4vw, 2.2rem) 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-rule-inverse);
  border: 1px solid var(--about-rule-inverse);
}

.page-about .scale-fact {
  background: var(--c-deep-2);
  padding: 1.1rem 1rem;
}

.page-about .scale-fact dt {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-steel-soft);
  margin-bottom: 0.5rem;
}

.page-about .scale-fact dd {
  margin: 0;
  font-family: var(--f-mono);
  font-size: clamp(1.35rem, 3.6vw, 1.7rem);
  font-weight: 600;
  line-height: 1;
  color: var(--c-amber-pale);
}

/* ---------- 团队 ---------- */
.page-about .team-figure {
  margin-bottom: clamp(1.5rem, 3vw, 2.2rem);
}

.page-about .team-bars {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.3rem;
  margin-top: clamp(1.4rem, 3vw, 2rem);
}

.page-about .team-bar__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.55rem;
}

.page-about .team-bar__name {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: 1.0625rem;
  color: var(--c-deep);
}

.page-about .team-bar__num {
  font-family: var(--f-mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--c-mono);
}

.page-about .team-bar__track {
  position: relative;
  height: 9px;
  background: var(--c-paper-2);
  overflow: hidden;
}

.page-about .team-bar__track::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 0;
}

.page-about .team-bar--eng .team-bar__track::after {
  width: 54%;
  background: var(--c-steel);
}

.page-about .team-bar--sup .team-bar__track::after {
  width: 31%;
  background: var(--c-steel-soft);
}

.page-about .team-bar--ops .team-bar__track::after {
  width: 15%;
  background: var(--c-amber);
}

.page-about .team-bar__note {
  margin: 0.6rem 0 0;
  font-size: 0.875rem;
  line-height: 1.72;
  color: rgba(32, 40, 42, 0.72);
}

/* ---------- 稳定交付 ---------- */
.page-about .about-section--delivery {
  background: var(--c-paper-2);
}

.page-about .delivery {
  list-style: none;
  margin: clamp(1.4rem, 3vw, 2rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  counter-reset: dv;
}

.page-about .delivery__item {
  position: relative;
  padding: 1.15rem 1.1rem 1.25rem;
  background: var(--c-paper);
  border-left: 3px solid var(--c-steel);
  border-radius: 0 14px 14px 0;
}

.page-about .delivery__item:nth-child(2) {
  border-left-color: var(--c-steel-soft);
}

.page-about .delivery__item:nth-child(3) {
  border-left-color: var(--c-amber);
}

.page-about .delivery__no {
  display: inline-block;
  font-family: var(--f-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--c-mono);
  background: rgba(143, 182, 188, 0.22);
  padding: 0.2rem 0.5rem;
  margin-bottom: 0.7rem;
}

.page-about .delivery__item h3 {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: 1.1875rem;
  line-height: 1.3;
  margin: 0 0 0.55rem;
  color: var(--c-deep);
}

.page-about .delivery__item p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(32, 40, 42, 0.82);
}

.page-about .delivery__tail {
  margin: clamp(1.5rem, 3vw, 2rem) 0 0;
  font-family: var(--f-editorial);
  font-size: 1rem;
  line-height: 1.85;
  color: var(--c-deep);
  max-width: 44ch;
  padding-left: 1rem;
  border-left: 2px solid var(--c-amber);
}

.page-about .delivery__tail a {
  color: var(--c-steel);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 600;
}

.page-about .delivery__tail a:hover {
  color: var(--c-amber);
}

/* ---------- 支持 ---------- */
.page-about .support-panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.4rem, 3.4vw, 2.6rem);
  padding: clamp(1.5rem, 4vw, 2.6rem) clamp(1.2rem, 3.5vw, 2.4rem);
  background: linear-gradient(135deg, rgba(27, 69, 58, 0.96), rgba(14, 42, 34, 0.98));
  color: var(--c-paper);
  border-radius: 4px 40px 4px 4px;
}

.page-about .support-panel .section-title {
  color: var(--c-paper);
}

.page-about .support-panel .prose {
  color: rgba(244, 241, 232, 0.82);
  max-width: 44ch;
}

.page-about .support-panel__aside {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  align-items: flex-start;
}

.page-about .support-facts {
  margin: 0;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
}

.page-about .support-facts > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--about-rule-inverse);
}

.page-about .support-facts dt {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-steel-soft);
}

.page-about .support-facts dd {
  margin: 0;
  font-family: var(--f-mono);
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--c-paper);
  text-align: right;
}

.page-about .support-facts dd .stat-num {
  font-size: 1.3125rem;
  color: var(--c-amber);
}

.page-about .support-panel__aside .btn {
  align-self: stretch;
  text-align: center;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .scale-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .delivery {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.25rem;
  }

  .page-about .lines {
    gap: 1.8rem;
  }

  .page-about .support-panel__aside .btn {
    align-self: flex-start;
  }
}

@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: end;
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .about-block {
    grid-template-columns: 9.5rem minmax(0, 1fr);
    gap: clamp(1.6rem, 3.5vw, 3.2rem);
  }

  .page-about .about-block__aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    padding-top: 0.35rem;
  }

  .page-about .scale-head {
    grid-template-columns: 9.5rem minmax(0, 1fr);
    gap: clamp(1.6rem, 3.5vw, 3.2rem);
  }

  .page-about .scale-head .about-block__aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }

  .page-about .timeline {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0 1.4rem;
    position: relative;
    padding-top: 0;
  }

  .page-about .timeline::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 45px;
    height: 1px;
    background: var(--c-steel-soft);
  }

  .page-about .timeline__item {
    padding-left: 0;
    border-left: 0;
  }

  .page-about .timeline__year {
    margin-bottom: 1.1rem;
  }

  .page-about .timeline__dot {
    display: block;
    position: relative;
    z-index: 1;
    width: 11px;
    height: 11px;
    margin-bottom: 1.35rem;
    border-radius: 50%;
    background: var(--c-paper);
    border: 2px solid var(--c-steel);
  }

  .page-about .timeline__item.is-current .timeline__dot {
    background: var(--c-amber);
    border-color: var(--c-amber);
    box-shadow: 0 0 0 4px rgba(227, 139, 36, 0.2);
  }

  .page-about .lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(1.6rem, 3vw, 2.4rem);
  }

  .page-about .team-bars {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

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

  .page-about .support-panel {
    grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-about .about-block {
    grid-template-columns: 11rem minmax(0, 1fr);
  }

  .page-about .scale-head {
    grid-template-columns: 11rem minmax(0, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .toc-rail a,
  .page-about .timeline__item,
  .page-about .delivery__item {
    transition: none;
  }
}