.page-about {
  --about-rail: 15rem;
  display: block;
  background: var(--cream);
  color: var(--ink);
  overflow-x: hidden;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(1.75rem, 4.5vw, 3rem) 0 clamp(3rem, 8vw, 6rem);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -34%;
  right: -20%;
  width: min(76%, 780px);
  aspect-ratio: 1 / 1;
  background: linear-gradient(150deg,
    rgba(37, 99, 235, 0.16),
    rgba(13, 148, 136, 0.13) 46%,
    rgba(249, 115, 22, 0.11) 78%,
    transparent 92%);
  clip-path: polygon(26% 0, 100% 0, 100% 74%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  left: 0;
  bottom: 0;
  width: min(40%, 430px);
  height: 4px;
  background: linear-gradient(90deg, var(--vermilion), var(--orange));
  pointer-events: none;
}

.page-about .about-hero-inner {
  position: relative;
}

.page-about .about-hero h1 {
  margin: 0.75rem 0 1.15rem;
  font-size: clamp(2.05rem, 5.6vw, 4.1rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.025em;
  color: var(--ink);
  max-width: 16em;
}

.page-about .about-hero-lede {
  margin: 0;
  max-width: 44rem;
  font-size: clamp(1rem, 1.5vw, 1.09rem);
  line-height: 1.85;
  color: var(--ink-soft);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: var(--sp-4);
}

/* ============ 主布局：索引栏 + 章节 ============ */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-4);
  padding-block: clamp(2.25rem, 6vw, 5rem);
}

.page-about .about-rail {
  border-top: 1px solid var(--line);
  padding-top: 0.85rem;
}

.page-about .about-rail-title {
  margin: 0 0 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--ink-faint);
}

.page-about .about-rail-list {
  display: flex;
  gap: 0.5rem;
  margin: 0;
  padding: 0 0 0.35rem;
  list-style: none;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scrollbar-width: none;
}

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

.page-about .about-rail-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  flex: 0 0 auto;
  padding: 0.45rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--white);
  color: var(--ink-soft);
  font-size: 0.82rem;
  line-height: 1.3;
  text-decoration: none;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-rail-link:hover,
.page-about .about-rail-link:focus-visible {
  border-color: var(--blue);
  color: var(--blue);
  background: var(--blue-wash);
}

.page-about .about-rail-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--vermilion);
}

@media (min-width: 60rem) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(2.5rem, 6vw, 5.5rem);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 6.5rem;
    border-top: 0;
    padding-top: 0;
  }

  .page-about .about-rail-list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    border-top: 1px solid var(--line);
  }

  .page-about .about-rail-link {
    display: grid;
    grid-template-columns: 2rem minmax(0, 1fr);
    align-items: baseline;
    gap: 0.5rem;
    width: 100%;
    padding: 0.7rem 0 0.7rem 0.9rem;
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: transparent;
    white-space: normal;
  }

  .page-about .about-rail-link:hover,
  .page-about .about-rail-link:focus-visible {
    border-left-color: var(--blue);
    background: var(--blue-wash);
    color: var(--blue);
  }
}

/* ============ 章节通用 ============ */
.page-about .about-section {
  scroll-margin-top: 6.5rem;
  padding-bottom: clamp(2.5rem, 5vw, 4rem);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-section + .about-section {
  padding-top: clamp(2.5rem, 5vw, 4rem);
}

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

.page-about .about-section-kicker {
  margin: 0;
  color: var(--teal);
  letter-spacing: 0.14em;
}

.page-about .about-section-title {
  margin: 0.55rem 0 0.9rem;
  font-size: clamp(1.55rem, 3.4vw, 2.35rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--ink);
  max-width: 22em;
}

.page-about .about-section-lede {
  margin: 0 0 var(--sp-3);
  max-width: 44rem;
  font-size: clamp(1rem, 1.4vw, 1.06rem);
  line-height: 1.85;
  color: var(--ink-soft);
}

.page-about .about-copy {
  max-width: 44rem;
}

.page-about .about-copy p {
  margin: 0 0 1.05rem;
  line-height: 1.85;
  color: var(--ink-soft);
}

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

.page-about .about-copy a,
.page-about .about-cap a,
.page-about .about-timeline-text a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(37, 99, 235, 0.35);
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}

.page-about .about-copy a:hover,
.page-about .about-cap a:hover,
.page-about .about-timeline-text a:hover {
  border-bottom-color: var(--blue);
  color: var(--ink-blue);
}

/* ============ 图片 ============ */
.page-about .about-figure {
  margin: var(--sp-4) 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--teal-gray);
  transition: border-color 0.2s var(--ease);
}

.page-about .about-figure:hover {
  border-color: var(--teal);
}

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

/* ============ 场景列表 ============ */
.page-about .about-scenarios {
  list-style: none;
  margin: var(--sp-4) 0 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-scenario {
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr);
  gap: 0.75rem;
  padding: 1.05rem 0;
  border-bottom: 1px solid var(--line-soft);
  transition: background 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.page-about .about-scenario:hover {
  background: var(--teal-wash);
  padding-left: 0.55rem;
}

.page-about .about-scenario-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--vermilion);
  padding-top: 0.25rem;
}

.page-about .about-scenario-title {
  margin: 0 0 0.3rem;
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.4;
}

.page-about .about-scenario-text {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ============ 能力卡片 ============ */
.page-about .about-capabilities {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: var(--sp-4);
}

.page-about .about-cap {
  position: relative;
  padding: 1.3rem 1.35rem 1.45rem;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .about-cap:hover {
  border-color: var(--blue);
  box-shadow: var(--shadow-float);
  transform: translateY(-2px);
}

.page-about .about-cap h3 {
  margin: 0.7rem 0 0.45rem;
  font-size: 1.08rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .about-cap p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.78;
  color: var(--ink-soft);
}

.page-about .about-cap-metric {
  display: inline-block;
  margin-top: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--teal);
}

@media (min-width: 46rem) {
  .page-about .about-capabilities {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-cap--full {
    grid-column: 1 / -1;
    padding-right: clamp(1.35rem, 8vw, 5rem);
  }
}

/* ============ 规模数据 ============ */
.page-about .about-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: var(--sp-4);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-stat {
  position: relative;
  padding: 1.45rem 1.2rem 1.6rem;
  background: var(--mist);
  transition: background 0.2s var(--ease);
}

.page-about .about-stat:hover {
  background: var(--teal-gray);
}

.page-about .about-stat::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 38px;
  height: 3px;
  background: var(--orange);
}

.page-about .about-stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.65rem, 3.8vw, 2.15rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--ink);
}

.page-about .about-stat-value .unit {
  font-size: 0.9rem;
  font-weight: 500;
  margin-left: 0.25rem;
  letter-spacing: 0;
  color: var(--ink-soft);
}

.page-about .about-stat-label {
  display: block;
  margin-top: 0.6rem;
  font-size: 0.87rem;
  line-height: 1.65;
  color: var(--ink-soft);
}

@media (min-width: 34rem) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ============ 演进时间轴 ============ */
.page-about .about-timeline {
  list-style: none;
  margin: var(--sp-4) 0 0;
  padding: 0 0 0 1.5rem;
  border-left: 1px solid var(--line);
}

.page-about .about-timeline-item {
  position: relative;
  padding-bottom: 1.85rem;
}

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

.page-about .about-timeline-item::before {
  content: "";
  position: absolute;
  left: -1.5rem;
  top: 0.45rem;
  width: 9px;
  height: 9px;
  margin-left: -5px;
  border: 2px solid var(--teal);
  border-radius: 50%;
  background: var(--cream);
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-timeline-item:hover::before {
  border-color: var(--orange);
  background: var(--orange);
}

.page-about .about-timeline-stage {
  display: block;
  margin-bottom: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--teal);
}

.page-about .about-timeline-title {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .about-timeline-text {
  margin: 0;
  max-width: 42rem;
  font-size: 0.94rem;
  line-height: 1.78;
  color: var(--ink-soft);
}

/* ============ 团队 ============ */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-4);
  margin-top: var(--sp-4);
}

.page-about .about-team-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-team-item {
  display: grid;
  gap: 0.35rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--line-soft);
  transition: padding-left 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-team-item:hover {
  padding-left: 0.55rem;
  background: var(--blue-wash);
}

.page-about .about-team-role {
  font-family: var(--font-mono);
  font-size: 0.79rem;
  letter-spacing: 0.06em;
  color: var(--ink);
}

.page-about .about-team-desc {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.78;
  color: var(--ink-soft);
}

@media (min-width: 34rem) {
  .page-about .about-team-item {
    grid-template-columns: 7rem minmax(0, 1fr);
    align-items: baseline;
    gap: 1.2rem;
  }
}

@media (min-width: 54rem) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    align-items: start;
    gap: clamp(1.5rem, 4vw, 3rem);
  }

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

/* ============ 尾部行动区 ============ */
.page-about .about-cta {
  position: relative;
  overflow: hidden;
  background: var(--ink-blue);
  color: var(--cream);
  padding-block: clamp(2.75rem, 7vw, 5rem);
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  top: -45%;
  right: -12%;
  width: min(62%, 620px);
  aspect-ratio: 1 / 1;
  background: radial-gradient(circle at 40% 45%,
    rgba(37, 99, 235, 0.58),
    rgba(13, 148, 136, 0.26) 46%,
    transparent 72%);
  pointer-events: none;
}

.page-about .about-cta-inner {
  position: relative;
  max-width: 46rem;
}

.page-about .about-cta h2 {
  margin: 0 0 0.85rem;
  font-size: clamp(1.6rem, 3.6vw, 2.4rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--cream);
}

.page-about .about-cta p {
  margin: 0 0 var(--sp-4);
  line-height: 1.8;
  color: rgba(251, 247, 239, 0.75);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about .about-cta .btn--ghost {
  border-color: rgba(251, 247, 239, 0.42);
  color: var(--cream);
}

.page-about .about-cta .btn--ghost:hover {
  border-color: var(--cream);
  background: rgba(251, 247, 239, 0.12);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-cap,
  .page-about .about-scenario,
  .page-about .about-team-item,
  .page-about .about-rail-link,
  .page-about .about-figure,
  .page-about .about-stat {
    transition: none;
  }

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