.page-about {
  --ab-hero-overlay: linear-gradient(135deg, rgba(26,26,26,0.70) 0%, rgba(26,26,26,0.25) 100%);
  --ab-timeline-dot-size: 16px;
  --ab-card-transition: transform 0.35s ease, box-shadow 0.35s ease;
  display: block;
  background-color: var(--color-gray, #5B5B5B);
  color: var(--color-white, #FFFFFF);
}

/* ── 首屏英雄 ── */
.page-about__hero {
  position: relative;
  overflow: hidden;
  min-height: 420px;
  display: flex;
  align-items: flex-end;
  padding: 0;
  margin-bottom: var(--space-lg, 2rem);
}

.page-about__hero-img-wrap {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.page-about__hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  display: block;
}

.page-about__hero-overlay {
  position: relative;
  z-index: 1;
  padding: var(--space-xl, 3rem) var(--space-md, 1rem) var(--space-lg, 2rem);
  background: var(--ab-hero-overlay);
  width: 100%;
}

.page-about__hero-label {
  display: inline-block;
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-small, 0.8rem);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-red, #E63946);
  border-left: 3px solid var(--color-red, #E63946);
  padding-left: 0.5rem;
  margin-bottom: var(--space-sm, 0.5rem);
}

.page-about__hero-title {
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-h1, 2.8rem);
  font-weight: var(--weight-h1, 900);
  line-height: 1.1;
  margin: 0 0 var(--space-sm, 0.5rem);
  color: var(--color-white, #FFFFFF);
  max-width: 14ch;
}

.page-about__hero-desc {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  line-height: 1.6;
  color: var(--color-light, #F4F4F4);
  max-width: 55ch;
  margin: 0;
}

.page-about__breadcrumb {
  position: absolute;
  top: var(--space-md, 1rem);
  left: var(--space-md, 1rem);
  z-index: 2;
  font-size: var(--size-small, 0.8rem);
  color: var(--color-border, #D3D3D3);
}

.page-about__breadcrumb a {
  color: var(--color-light, #F4F4F4);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.page-about__breadcrumb a:hover {
  border-color: var(--color-red, #E63946);
}

/* ── 使命区 ── */
.page-about__mission {
  padding: var(--space-xl, 3rem) 0;
  background-color: var(--color-dark, #1A1A1A);
}

.page-about__mission-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg, 2rem);
}

.page-about__mission-text {
  max-width: 720px;
}

.page-about__section-title {
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-h2, 2rem);
  font-weight: var(--weight-h2, 700);
  margin: 0 0 var(--space-md, 1rem);
  color: var(--color-white, #FFFFFF);
  position: relative;
}

.page-about__section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--color-red, #E63946);
  margin-top: var(--space-xs, 0.25rem);
}

.page-about__mission-para {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  line-height: 1.75;
  color: var(--color-light, #F4F4F4);
  margin: 0 0 var(--space-md, 1rem);
}

.page-about__mission-para:last-child {
  margin-bottom: 0;
}

.page-about__mission-stat {
  display: flex;
  gap: var(--space-md, 1rem);
  flex-wrap: wrap;
}

.page-about__stat-card {
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--color-border, #D3D3D3);
  border-radius: var(--radius, 4px);
  padding: var(--space-md, 1rem) var(--space-lg, 2rem);
  text-align: center;
  flex: 1 1 120px;
  transition: var(--ab-card-transition);
}

.page-about__stat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover, 0 4px 16px rgba(0,0,0,0.12));
}

.page-about__stat-number {
  display: block;
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-h1, 2.8rem);
  font-weight: var(--weight-h1, 900);
  color: var(--color-red, #E63946);
  line-height: 1;
}

.page-about__stat-label {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-small, 0.8rem);
  color: var(--color-border, #D3D3D3);
  display: block;
  margin-top: var(--space-xs, 0.25rem);
}

/* ── 时间轴 ── */
.page-about__timeline-wrap {
  padding: var(--space-xl, 3rem) 0 var(--space-lg, 2rem);
  background-color: var(--color-gray, #5B5B5B);
}

.page-about__timeline-heading {
  margin-bottom: var(--space-xs, 0.25rem);
}

.page-about__timeline-sub {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  color: var(--color-border, #D3D3D3);
  margin: 0 0 var(--space-lg, 2rem);
}

.page-about__timeline {
  position: relative;
  padding: var(--space-lg, 2rem) 0;
}

.page-about__timeline-track {
  position: absolute;
  top: 0;
  left: 24px;
  width: 2px;
  height: 100%;
  background: repeating-linear-gradient(to bottom, #D3D3D3 0px, #D3D3D3 6px, transparent 6px, transparent 10px);
}

.page-about__timeline-svg {
  display: none;
}

.page-about__timeline-items {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg, 2rem);
  position: relative;
}

.page-about__timeline-item {
  display: flex;
  gap: var(--space-md, 1rem);
  align-items: flex-start;
}

.page-about__tl-marker {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
  width: 32px;
  position: relative;
  z-index: 1;
}

.page-about__tl-step {
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-small, 0.8rem);
  color: var(--color-gray, #5B5B5B);
  background: var(--color-red, #E63946);
  border-radius: 50%;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.page-about__tl-dot {
  display: block;
  width: var(--ab-timeline-dot-size);
  height: var(--ab-timeline-dot-size);
  border-radius: 50%;
  background: var(--color-red, #E63946);
  border: 3px solid var(--color-gray, #5B5B5B);
  box-shadow: 0 0 0 2px var(--color-red, #E63946);
  flex-shrink: 0;
}

.page-about__tl-dot--future {
  background: var(--color-green, #2A9D8F);
  border-color: var(--color-gray, #5B5B5B);
  box-shadow: 0 0 0 2px var(--color-green, #2A9D8F);
}

.page-about__tl-card {
  flex: 1;
  background: var(--color-dark, #1A1A1A);
  border-left: 3px solid var(--color-red, #E63946);
  padding: var(--space-md, 1rem) var(--space-md, 1rem);
  transition: var(--ab-card-transition);
}

.page-about__tl-card:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-hover, 0 4px 16px rgba(0,0,0,0.12));
}

.page-about__tl-title {
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-h3, 1.4rem);
  font-weight: var(--weight-h2, 700);
  margin: 0 0 var(--space-xs, 0.25rem);
  color: var(--color-white, #FFFFFF);
}

.page-about__tl-desc {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  line-height: 1.6;
  color: var(--color-light, #F4F4F4);
  margin: 0;
}

/* ── 服务范围 ── */
.page-about__services {
  padding: var(--space-xl, 3rem) 0;
  background-color: var(--color-dark, #1A1A1A);
}

.page-about__services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md, 1rem);
  margin-bottom: var(--space-lg, 2rem);
}

.page-about__service-card {
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--color-border, #D3D3D3);
  padding: var(--space-lg, 2rem) var(--space-md, 1rem);
  text-align: center;
  transition: var(--ab-card-transition);
}

.page-about__service-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover, 0 4px 16px rgba(0,0,0,0.12));
  border-color: var(--color-red, #E63946);
}

.page-about__service-icon {
  margin-bottom: var(--space-sm, 0.5rem);
  display: inline-flex;
}

.page-about__service-title {
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-h3, 1.4rem);
  font-weight: var(--weight-h2, 700);
  margin: 0 0 var(--space-sm, 0.5rem);
  color: var(--color-white, #FFFFFF);
}

.page-about__service-desc {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  line-height: 1.6;
  color: var(--color-border, #D3D3D3);
  margin: 0;
}

.page-about__services-visual {
  margin-top: var(--space-lg, 2rem);
  text-align: center;
}

.page-about__services-img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius, 4px);
  border: 1px solid var(--color-border, #D3D3D3);
  display: block;
  margin: 0 auto;
}

.page-about__services-caption {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-small, 0.8rem);
  color: var(--color-border, #D3D3D3);
  margin-top: var(--space-sm, 0.5rem);
  font-style: italic;
}

/* ── 数据来源 ── */
.page-about__source {
  padding: var(--space-xl, 3rem) 0;
  background-color: var(--color-gray, #5B5B5B);
}

.page-about__source-inner {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
}

.page-about__source-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm, 0.5rem);
  background: rgba(42,157,143,0.12);
  border: 1px solid var(--color-green, #2A9D8F);
  border-radius: 32px;
  padding: var(--space-sm, 0.5rem) var(--space-md, 1rem);
  margin-bottom: var(--space-md, 1rem);
}

.page-about__source-badge-text {
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-small, 0.8rem);
  color: var(--color-green, #2A9D8F);
  letter-spacing: 0.05em;
}

.page-about__source-desc {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  line-height: 1.75;
  color: var(--color-light, #F4F4F4);
  margin: 0 0 var(--space-lg, 2rem);
}

.page-about__source-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm, 0.5rem);
  align-items: center;
}

.page-about__source-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm, 0.5rem);
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  color: var(--color-light, #F4F4F4);
}

.page-about__source-mark {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 1px;
  background: var(--color-green, #2A9D8F);
  transform: rotate(45deg);
  flex-shrink: 0;
}

/* ── 未来愿景 ── */
.page-about__vision {
  padding: var(--space-xl, 3rem) 0;
  background-color: var(--color-dark, #1A1A1A);
}

.page-about__vision-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg, 2rem);
  align-items: center;
}

.page-about__vision-text {
  max-width: 600px;
}

.page-about__vision-para {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  line-height: 1.75;
  color: var(--color-light, #F4F4F4);
  margin: 0 0 var(--space-md, 1rem);
}

.page-about__vision-links {
  display: flex;
  gap: var(--space-md, 1rem);
  flex-wrap: wrap;
  margin-top: var(--space-lg, 2rem);
}

.page-about__vision-img-wrap {
  width: 100%;
  max-width: 560px;
}

.page-about__vision-img {
  width: 100%;
  height: auto;
  border-radius: var(--radius, 4px);
  border: 1px solid var(--color-border, #D3D3D3);
  display: block;
}

/* ── CTA ── */
.page-about__cta {
  padding: var(--space-xl, 3rem) 0;
  background-color: var(--color-gray, #5B5B5B);
  text-align: center;
}

.page-about__cta-inner {
  max-width: 600px;
  margin: 0 auto;
}

.page-about__cta-title {
  font-family: var(--font-headline, Impact, 'Arial Black', sans-serif);
  font-size: var(--size-h2, 2rem);
  font-weight: var(--weight-h2, 700);
  color: var(--color-white, #FFFFFF);
  margin: 0 0 var(--space-sm, 0.5rem);
}

.page-about__cta-desc {
  font-family: var(--font-body, 'Noto Serif SC', serif);
  font-size: var(--size-body, 1rem);
  color: var(--color-light, #F4F4F4);
  margin: 0 0 var(--space-lg, 2rem);
}

.page-about__cta-actions {
  display: flex;
  gap: var(--space-md, 1rem);
  justify-content: center;
  flex-wrap: wrap;
}

/* ── 滚动显现动画 ── */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

[data-reveal][data-revealed] {
  opacity: 1;
  transform: translateY(0);
}

[data-reveal-delay] {
  transition-delay: attr(data-reveal-delay ms, 0ms);
}

@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ── 桌面端 ── */
@media (min-width: 768px) {
  .page-about__hero {
    min-height: 520px;
  }

  .page-about__hero-overlay {
    padding: var(--space-2xl, 4rem) var(--space-xl, 3rem);
  }

  .page-about__hero-title {
    font-size: 3.6rem;
    max-width: 16ch;
  }

  .page-about__hero-desc {
    font-size: 1.1rem;
  }

  .page-about__mission-grid {
    flex-direction: row;
    align-items: flex-start;
    justify-content: space-between;
  }

  .page-about__mission-text {
    flex: 2;
  }

  .page-about__mission-stat {
    flex: 1;
    justify-content: flex-end;
  }

  .page-about__stat-card {
    flex: 0 1 auto;
    min-width: 140px;
  }

  .page-about__timeline-track {
    display: none;
  }

  .page-about__timeline-svg {
    display: block;
    width: 100%;
    height: 8px;
  }

  .page-about__timeline-items {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-lg, 2rem);
    justify-content: space-between;
  }

  .page-about__timeline-item {
    flex: 1 1 200px;
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .page-about__tl-marker {
    width: auto;
    margin-bottom: var(--space-sm, 0.5rem);
  }

  .page-about__tl-card {
    border-left: none;
    border-top: 3px solid var(--color-red, #E63946);
  }

  .page-about__tl-card:hover {
    transform: translateY(-4px);
  }

  .page-about__services-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg, 2rem);
  }

  .page-about__vision-grid {
    flex-direction: row;
    justify-content: space-between;
  }

  .page-about__vision-img-wrap {
    max-width: 440px;
  }

  .page-about__source-list {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-md, 1rem) var(--space-lg, 2rem);
  }
}

@media (min-width: 1024px) {
  .page-about__hero-title {
    font-size: 4rem;
  }

  .page-about__mission-stat {
    gap: var(--space-lg, 2rem);
  }

  .page-about__services-grid {
    gap: var(--space-xl, 3rem);
  }
}