.page-about {
  --about-rail-width: 220px;
  --about-accent-soft: rgba(0, 229, 168, 0.1);
  --about-accent-glow: rgba(0, 229, 168, 0.18);
}

.page-about__context {
  padding-top: 28px;
  padding-bottom: 4px;
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
}

.page-about .breadcrumb a {
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.page-about .breadcrumb a:hover {
  color: var(--color-accent);
}

.page-about .breadcrumb .breadcrumb__sep {
  opacity: 0.5;
}

.page-about__intro {
  position: relative;
  padding: 44px 0 52px;
  background:
    radial-gradient(ellipse at 85% 15%, rgba(0, 229, 168, 0.07), transparent 48%),
    linear-gradient(180deg, rgba(5, 10, 24, 0.5), transparent);
}

.page-about__intro-inner {
  display: grid;
  gap: 32px;
  align-items: center;
}

.page-about__intro-copy {
  position: relative;
}

.page-about__intro-copy h1 {
  font-family: var(--font-display);
  font-size: clamp(32px, 6vw, 56px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 16px 0 12px;
  max-width: 11em;
  color: var(--color-text-primary);
}

.page-about__lead {
  font-family: var(--font-display);
  font-size: clamp(16px, 2.4vw, 22px);
  font-weight: 500;
  color: var(--color-accent);
  margin: 0 0 20px;
  letter-spacing: 0.01em;
}

.page-about__intro-text {
  max-width: 42em;
  color: var(--color-text-secondary);
  line-height: 1.75;
  font-size: 15px;
  margin: 0 0 28px;
}

.page-about__intro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about__intro-panel {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.page-about__intro-panel-head {
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about__intro-panel-title {
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-secondary);
  letter-spacing: 0.02em;
}

.page-about__intro-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 0;
}

.page-about__intro-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about__intro-stat dt {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-secondary);
  letter-spacing: 0.04em;
}

.page-about__intro-stat dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.1;
}

.page-about__intro-panel-foot {
  font-size: 12px;
  color: var(--color-text-secondary);
  border-top: 1px solid var(--color-divider);
  padding-top: 14px;
  margin: 0;
  letter-spacing: 0.02em;
}

.page-about__layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-top: 20px;
  padding-bottom: 64px;
}

.page-about__rail {
  display: none;
}

.page-about__content {
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* 01 · 平台由来 */
.page-about__origin {
  padding: 36px 0 56px;
}

.page-about__origin-head,
.page-about__section-head {
  margin-bottom: 28px;
}

.page-about__origin-head h2,
.page-about__section-head h2 {
  font-family: var(--font-display);
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 700;
  line-height: 1.3;
  margin: 10px 0 14px;
  color: var(--color-text-primary);
  position: relative;
}

.page-about__section-head h2::after {
  content: "";
  display: inline-block;
  width: 42px;
  height: 3px;
  margin-left: 14px;
  background: linear-gradient(90deg, var(--color-accent), transparent);
  transform: skewX(-24deg);
  vertical-align: middle;
}

.page-about__origin-head p,
.page-about__section-head p {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin: 0;
}

.page-about__origin-body p {
  color: var(--color-text-secondary);
  line-height: 1.8;
  font-size: 15px;
  margin: 0 0 16px;
  max-width: 44em;
}

.page-about__origin-body p:last-child {
  margin-bottom: 0;
}

.page-about__origin-note {
  margin-top: 28px;
  padding: 18px 22px;
  border-left: 3px solid var(--color-accent);
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text-primary);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about__origin-note-label {
  font-size: 12px;
  color: var(--color-accent);
  letter-spacing: 0.1em;
}

/* 02 · 发展里程碑 */
.page-about__milestones {
  padding: 56px 0;
  border-top: 1px solid var(--color-divider);
}

.page-about__milestone-hero {
  margin: 8px 0 44px;
}

.page-about__milestone-hero img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  display: block;
}

.page-about__milestone-list {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about__milestone-list::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--color-accent) 0%, var(--color-divider) 32%, var(--color-divider) 100%);
}

.page-about__milestone-item {
  display: grid;
  grid-template-columns: 14px minmax(0, 1fr);
  gap: 18px;
  padding-bottom: 32px;
}

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

.page-about__milestone-marker {
  position: relative;
  width: 14px;
  height: 14px;
  margin-top: 4px;
}

.page-about__milestone-marker::before {
  content: "";
  display: block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 4px var(--color-primary-bg), 0 0 14px rgba(0, 229, 168, 0.55);
}

.page-about__milestone-marker::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
  animation: page-about-pulse 2.4s ease-out infinite;
  pointer-events: none;
}

@keyframes page-about-pulse {
  0% {
    transform: scale(1);
    opacity: 0.7;
  }
  100% {
    transform: scale(2.6);
    opacity: 0;
  }
}

.page-about__milestone-year {
  display: inline-block;
  font-size: 13px;
  color: var(--color-accent);
  letter-spacing: 0.12em;
  margin-bottom: 8px;
}

.page-about__milestone-card {
  padding: 20px 22px;
}

.page-about__milestone-card h3 {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-text-primary);
  margin: 0 0 10px;
}

.page-about__milestone-card p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin: 0;
}

/* 03 · 数据覆盖能力 */
.page-about__data {
  padding: 56px 0;
  border-top: 1px solid var(--color-divider);
  position: relative;
}

.page-about__data-grid {
  display: grid;
  gap: 32px;
  align-items: start;
}

.page-about__stat-group {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.page-about__stat {
  background: var(--color-surface-glass);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 0;
}

.page-about__stat-num {
  font-family: var(--font-display);
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.1;
  display: block;
}

.page-about__stat-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-primary);
}

.page-about__stat p {
  margin: 4px 0 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--color-text-secondary);
}

.page-about__data-map {
  margin: 0;
}

.page-about__data-map img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  display: block;
}

.page-about__data-note {
  margin-top: 24px;
  font-size: 13px;
  line-height: 1.7;
}

.page-about__data-note a {
  color: var(--color-accent);
  text-decoration: none;
}

.page-about__data-note a:hover {
  text-decoration: underline;
}

/* 04 · 华人服务理念 */
.page-about__service {
  padding: 56px 0;
  border-top: 1px solid var(--color-divider);
}

.page-about__service-hero {
  margin: 8px 0 40px;
}

.page-about__service-hero img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  display: block;
  object-fit: cover;
}

.page-about__service-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about__service-feature {
  padding: 22px;
  border-left: 3px solid var(--color-accent);
}

.page-about__service-code {
  font-size: 12px;
  color: var(--color-accent-alt);
  display: block;
  margin-bottom: 10px;
  letter-spacing: 0.12em;
}

.page-about__service-feature h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text-primary);
  margin: 0 0 8px;
}

.page-about__service-feature p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin: 0;
}

/* 结尾 */
.page-about__outro {
  padding: 48px 0 0;
  border-top: 1px solid var(--color-divider);
}

.page-about__outro-inner {
  background: var(--color-secondary-glass);
  border: 1px solid var(--color-divider);
  border-radius: calc(var(--radius) * 2);
  padding: 36px 24px;
  text-align: center;
}

.page-about__outro h2 {
  font-family: var(--font-display);
  font-size: clamp(24px, 3.4vw, 32px);
  font-weight: 700;
  color: var(--color-text-primary);
  margin: 0 0 14px;
}

.page-about__outro p {
  color: var(--color-text-secondary);
  max-width: 34em;
  margin: 0 auto 28px;
  line-height: 1.8;
  font-size: 15px;
}

.page-about__outro-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

/* 平板及以上 */
@media (min-width: 768px) {
  .page-about__intro {
    padding: 56px 0 64px;
  }

  .page-about__intro-inner {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 40px;
  }

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

  .page-about__service-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}

/* 桌面端 */
@media (min-width: 992px) {
  .page-about__intro {
    padding: 72px 0 84px;
  }

  .page-about__layout {
    grid-template-columns: var(--about-rail-width) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
    padding-top: 24px;
  }

  .page-about__rail {
    display: block;
    position: sticky;
    top: calc(var(--header-height) + 32px);
  }

  .page-about__rail-list {
    list-style: none;
    margin: 0 0 32px;
    padding: 0;
  }

  .page-about__rail-item + .page-about__rail-item {
    margin-top: 4px;
  }

  .page-about__rail-link {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    text-decoration: none;
    border-left: 2px solid transparent;
    transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  }

  .page-about__rail-link:hover {
    color: var(--color-text-primary);
    background: var(--color-surface);
    border-left-color: var(--color-accent);
  }

  .page-about__rail-index {
    font-size: 12px;
    color: var(--color-accent);
    line-height: 1;
  }

  .page-about__rail-label {
    font-size: 14px;
    font-weight: 500;
  }

  .page-about__rail-note {
    font-size: 13px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    border-top: 1px solid var(--color-divider);
    padding-top: 20px;
  }

  .page-about__rail-note a {
    color: var(--color-accent);
    text-decoration: none;
  }

  .page-about__rail-note a:hover {
    text-decoration: underline;
  }

  .page-about__data-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 48px;
  }
}

/* 大屏 */
@media (min-width: 1280px) {
  .page-about__service-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }
}

/* 减少动态偏好 */
@media (prefers-reduced-motion: reduce) {
  .page-about__milestone-marker::after {
    animation: none;
    display: none;
  }
}