.page-about {
  --tl-year-w: 64px;
  --tl-gap: 12px;
  --tl-rail-w: 20px;
  min-height: 100vh;
  background: var(--primary-deep-blue);
  color: var(--text-primary);
  overflow-x: hidden;
}

/* ===== Hero ===== */
.page-about .about-hero {
  position: relative;
  padding: 24px 0 64px;
  background-color: var(--primary-deep-blue);
  background-image:
    linear-gradient(rgba(42, 59, 92, 0.32) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 92, 0.32) 1px, transparent 1px);
  background-size: 28px 28px;
  overflow: hidden;
}
.page-about .about-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(125deg, rgba(10, 17, 40, 0.78) 0%, rgba(10, 17, 40, 0.32) 48%, rgba(17, 29, 58, 0.85) 100%);
  pointer-events: none;
}
.page-about .about-hero::after {
  content: '';
  position: absolute;
  right: -80px;
  top: 24px;
  width: 320px;
  height: 320px;
  border: 1px dashed rgba(61, 255, 139, 0.25);
  border-radius: 50%;
  pointer-events: none;
}
.page-about .about-hero .container {
  position: relative;
  z-index: 1;
}
.page-about .about-hero-layout {
  display: grid;
  gap: 28px;
  padding-top: 32px;
}
.page-about .about-hero-copy .section-index {
  margin-bottom: 14px;
}
.page-about .about-hero-copy h1 {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 32px;
  line-height: 1.24;
  letter-spacing: -0.01em;
  margin: 6px 0 18px;
  max-width: 660px;
}
.page-about .about-hero-lead {
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.85;
  margin-bottom: 22px;
  max-width: 560px;
}
.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ===== 系统身份卡 ===== */
.page-about .about-identity-card {
  background: rgba(17, 29, 58, 0.72);
  border: 1px solid var(--border-line);
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  padding: 20px 20px 16px;
  position: relative;
  overflow: hidden;
}
.page-about .about-identity-card::after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--neon-green), var(--gold-highlight));
  opacity: 0.7;
}
.page-about .identity-card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 12px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--border-line);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}
.page-about .identity-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--neon-green);
  animation: about-dot-pulse 2.4s ease-in-out infinite;
}
.page-about .identity-fid {
  margin-left: auto;
  font-size: 11px;
  color: var(--text-muted);
  opacity: 0.6;
}
.page-about .identity-list {
  margin: 0;
  padding: 0;
  display: grid;
}
.page-about .identity-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px dashed rgba(42, 59, 92, 0.7);
  gap: 12px;
}
.page-about .identity-row:last-child {
  border-bottom: 0;
}
.page-about .identity-row dt {
  color: var(--text-muted);
  font-size: 13px;
}
.page-about .identity-row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 14px;
  color: var(--text-primary);
}
.page-about .identity-card-foot {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--border-line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
}

/* ===== 曲线分隔线 ===== */
.page-about .about-divider {
  height: 36px;
  margin: 0;
  background: transparent;
}
.page-about .about-divider svg {
  display: block;
  width: 100%;
  height: 100%;
}

/* ===== 板块背景节奏 ===== */
.page-about .about-origin,
.page-about .about-milestones,
.page-about .about-cert {
  background-color: var(--primary-deep-blue);
}
.page-about .about-mission {
  background-color: rgba(17, 29, 58, 0.65);
  border-top: 1px solid var(--border-line);
  border-bottom: 1px solid var(--border-line);
}
.page-about .about-tech {
  background-color: var(--primary-deep-blue);
  background-image:
    linear-gradient(rgba(42, 59, 92, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 92, 0.22) 1px, transparent 1px);
  background-size: 28px 28px;
}
.page-about .about-extend {
  background-image:
    linear-gradient(rgba(42, 59, 92, 0.28) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 59, 92, 0.28) 1px, transparent 1px);
  background-size: 28px 28px;
  border-top: 1px solid var(--border-line);
}

/* ===== Origin ===== */
.page-about .about-origin-layout {
  display: grid;
  gap: 28px;
  margin-top: 28px;
}
.page-about .about-origin-map {
  background: var(--secondary-blue);
  border: 1px solid var(--border-line);
  border-radius: 12px;
  padding: 18px;
}
.page-about .about-hebei-svg {
  width: 100%;
  height: auto;
  display: block;
}
.page-about .about-map-shape {
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: stroke 0.3s ease;
}
.page-about .about-origin-map:hover .about-map-shape {
  stroke: var(--neon-green);
  stroke-width: 2;
}
.page-about .about-map-hint {
  transition: font-size 0.2s ease;
}
.page-about .about-origin-map:hover .about-map-hint {
  font-size: 12.5px;
  stroke: var(--primary-deep-blue);
  stroke-width: 0.5px;
  paint-order: stroke;
}
.page-about .about-map-pulse-ring {
  transform-box: fill-box;
  transform-origin: center;
  animation: about-map-ping 2.2s cubic-bezier(0, 0, 0.2, 1) infinite;
}
.page-about .about-map-legend {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--border-line);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
}
.page-about .about-map-legend-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold-highlight);
  box-shadow: 0 0 0 3px rgba(255, 193, 7, 0.2);
}
.page-about .about-origin-copy p {
  color: var(--text-muted);
  line-height: 1.9;
  margin-bottom: 16px;
  font-size: 14px;
}
.page-about .about-origin-copy p:first-of-type {
  color: var(--text-primary);
  font-size: 17px;
  font-weight: 500;
}

/* ===== 图片容器 ===== */
.page-about .about-media {
  margin: 0;
}
.page-about .about-media-img {
  display: block;
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  border: 1px solid var(--border-line);
  object-fit: cover;
}
.page-about .about-origin-figure {
  margin-top: 24px;
}
.page-about .about-origin-figure img {
  aspect-ratio: 3 / 2;
}
.page-about .about-mission-figure img {
  aspect-ratio: 10 / 7;
}
.page-about .about-tech-banner img {
  aspect-ratio: 7 / 4;
}
.page-about .media-caption {
  margin-top: 8px;
  color: var(--text-muted);
}

/* ===== Mission ===== */
.page-about .about-mission-layout {
  display: grid;
  gap: 28px;
  margin-top: 28px;
}
.page-about .about-mission-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.page-about .about-mission-item {
  background: var(--card-blue);
  border: 1px solid var(--border-line);
  border-radius: 12px;
  padding: 18px 20px;
  position: relative;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.page-about .about-mission-item:hover {
  transform: translateY(-3px);
  border-color: var(--neon-green);
}
.page-about .about-mission-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 12px;
  color: var(--gold-highlight);
  letter-spacing: 0.12em;
  margin-bottom: 8px;
}
.page-about .about-mission-item h3 {
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 6px;
}
.page-about .about-mission-item p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.75;
  margin: 0;
}

/* ===== 时间线 ===== */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 12px 0 0;
  position: relative;
}
.page-about .about-timeline::before {
  content: '';
  position: absolute;
  left: calc(var(--tl-year-w) + var(--tl-gap) + var(--tl-rail-w) / 2);
  top: 10px;
  bottom: 32px;
  width: 1px;
  background: var(--border-line);
}
.page-about .timeline-item {
  display: flex;
  align-items: flex-start;
  gap: var(--tl-gap);
  padding-bottom: 28px;
}
.page-about .timeline-year {
  width: var(--tl-year-w);
  flex-shrink: 0;
  text-align: right;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 15px;
  color: var(--gold-highlight);
  padding-top: 2px;
}
.page-about .timeline-connector {
  width: var(--tl-rail-w);
  flex-shrink: 0;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  height: 28px;
}
.page-about .timeline-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--neon-green);
  border: 2px solid var(--primary-deep-blue);
  box-shadow: 0 0 0 2px var(--neon-green);
  margin-top: 5px;
  position: relative;
  z-index: 1;
  transition: box-shadow 0.2s ease, background 0.2s ease;
}
.page-about .timeline-item:hover .timeline-dot {
  background: var(--gold-highlight);
  box-shadow: 0 0 0 4px rgba(255, 193, 7, 0.35);
}
.page-about .timeline-card {
  flex: 1;
  min-width: 0;
  background: var(--card-blue);
  border: 1px solid var(--border-line);
  border-radius: 10px;
  padding: 12px 16px;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.page-about .timeline-card:hover {
  border-color: rgba(61, 255, 139, 0.5);
}
.page-about .timeline-card summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 16px;
  color: var(--text-primary);
}
.page-about .timeline-card summary::-webkit-details-marker {
  display: none;
}
.page-about .timeline-card summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--gold-highlight);
  transition: transform 0.2s ease;
  flex-shrink: 0;
}
.page-about .timeline-card[open] summary::after {
  transform: rotate(45deg);
}
.page-about .timeline-card p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.75;
  margin: 10px 0 2px;
  padding-top: 10px;
  border-top: 1px dashed rgba(42, 59, 92, 0.8);
}

/* ===== 技术底座 ===== */
.page-about .about-tech-banner {
  margin-bottom: 28px;
}
.page-about .about-tech-layout {
  display: grid;
  gap: 24px;
}
.page-about .about-tech-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .about-stat {
  background: var(--card-blue);
  border: 1px solid var(--border-line);
  border-radius: 10px;
  padding: 18px;
}
.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 26px;
  line-height: 1;
  color: var(--neon-green);
}
.page-about .about-stat-unit {
  display: block;
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 6px;
}
.page-about .about-stat p {
  color: var(--text-muted);
  font-size: 13px;
  line-height: 1.65;
  margin: 10px 0 0;
}
.page-about .about-tech-features {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.page-about .about-tech-feature {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  background: rgba(17, 29, 58, 0.6);
  border: 1px solid var(--border-line);
  border-radius: 10px;
  padding: 18px;
  transition: border-color 0.2s ease;
}
.page-about .about-tech-feature:hover {
  border-color: var(--gold-highlight);
}
.page-about .tech-feature-alph {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  border: 1px solid var(--gold-highlight);
  border-radius: 8px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  color: var(--gold-highlight);
}
.page-about .about-tech-feature h3 {
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 6px;
}
.page-about .about-tech-feature p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.7;
  margin: 0;
}

/* ===== 资质与荣誉 ===== */
.page-about .about-cert-grid {
  display: grid;
  gap: 20px;
}
.page-about .about-cert-card {
  background: var(--secondary-blue);
  border: 1px solid var(--border-line);
  border-radius: 12px;
  padding: 24px 22px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.page-about .about-cert-card:hover {
  border-color: var(--gold-highlight);
  transform: translateY(-3px);
}
.page-about .about-cert-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--gold-highlight);
  border-radius: 10px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 14px;
  color: var(--gold-highlight);
  margin-bottom: 16px;
}
.page-about .about-cert-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
}
.page-about .about-cert-card p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.75;
  margin: 0;
}
.page-about .about-cert-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 28px;
  background: var(--card-blue);
  border: 1px dashed var(--border-line);
  border-radius: 10px;
  padding: 18px 20px;
}
.page-about .about-cert-bottom p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
}

/* ===== 延伸阅读 ===== */
.page-about .about-extend-inner {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
  padding: 28px 0;
}
.page-about .about-extend-inner h2 {
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 800;
  margin: 8px 0 4px;
}
.page-about .about-extend-inner p {
  color: var(--text-muted);
  font-size: 14px;
  margin: 0;
}

/* ===== Keyframes ===== */
@keyframes about-dot-pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(61, 255, 139, 0.5);
    opacity: 1;
  }
  50% {
    box-shadow: 0 0 0 8px rgba(61, 255, 139, 0);
    opacity: 0.7;
  }
}
@keyframes about-map-ping {
  0% {
    transform: scale(1);
    opacity: 0.7;
  }
  80%, 100% {
    transform: scale(2.8);
    opacity: 0;
  }
}

/* ===== 响应式 ===== */
@media (min-width: 520px) {
  .page-about .about-tech-stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .page-about .about-hero-layout {
    grid-template-columns: 1.35fr 1fr;
    align-items: center;
    gap: 48px;
    padding-top: 48px;
    min-height: 440px;
  }
  .page-about .about-hero-copy h1 {
    font-size: 44px;
  }
  .page-about .about-hero-lead {
    font-size: 17px;
  }
  .page-about .about-origin-layout {
    grid-template-columns: 0.9fr 1.1fr;
    gap: 40px;
    align-items: start;
  }
  .page-about .about-mission-layout {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
  }
  .page-about .about-tech-layout {
    grid-template-columns: 1fr 1.2fr;
    gap: 32px;
    align-items: start;
  }
  .page-about .about-cert-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }
  .page-about .about-extend-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
  .page-about .about-timeline {
    --tl-year-w: 88px;
    --tl-gap: 16px;
    --tl-rail-w: 24px;
  }
  .page-about .about-timeline::before {
    left: calc(var(--tl-year-w) + var(--tl-gap) + var(--tl-rail-w) / 2);
  }
  .page-about .timeline-year {
    font-size: 18px;
  }
  .page-about .timeline-card {
    padding: 16px 22px;
  }
  .page-about .about-mission-list {
    gap: 16px;
  }
}