.page-about {
  --about-gap: clamp(24px, 4vw, 64px);
  --about-muted: #6B7A93;
  --about-line: rgba(44, 62, 107, 0.35);
  --about-card-radius: 12px;
  --about-clip: polygon(12px 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%, 0 12px);
  --about-font-mono: "Roboto Mono", "Consolas", "SF Mono", Menlo, monospace;
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  overflow-x: hidden;
}
.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}
.page-about img {
  display: block;
  max-width: 100%;
  height: auto;
}
.page-about h1,
.page-about h2,
.page-about h3 {
  font-weight: 700;
  color: var(--color-text-primary);
  line-height: 1.25;
}
.page-about a {
  color: inherit;
  text-decoration: none;
}
.page-about p {
  margin: 0 0 1em;
}
.page-about blockquote {
  margin: 0;
}
.page-about ol,
.page-about ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about figure {
  margin: 0;
}

/* ===== Hero ===== */
.page-about-hero {
  position: relative;
  background: var(--color-deep);
  color: var(--color-light);
  padding: clamp(28px, 5vw, 64px) clamp(16px, 4vw, 56px);
  clip-path: var(--about-clip);
}
.page-about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 180px;
  height: 180px;
  background: repeating-linear-gradient(135deg, transparent 0 8px, rgba(255, 107, 53, 0.14) 8px 9px);
  clip-path: polygon(0 0, 100% 0, 100% 100%);
  pointer-events: none;
}
.page-about-hero::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), transparent);
  opacity: 0.6;
}
.page-about-hero-route {
  font-family: var(--about-font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--color-neon);
  margin: 0 0 12px;
  opacity: 0.9;
}
.page-about-hero h1 {
  font-size: clamp(36px, 6vw, 56px);
  color: #fff;
  margin: 0;
  letter-spacing: -0.02em;
}
.page-about-hero-sub {
  font-size: clamp(18px, 2.6vw, 24px);
  color: var(--color-rail-text);
  margin: 10px 0 18px;
  font-weight: 500;
}
.page-about-hero-desc {
  color: #C9D4E6;
  font-size: 16px;
  max-width: 46em;
}
.page-about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}
.page-about-hero-preview {
  margin-top: 36px;
  border: 1px solid var(--color-border);
  background: rgba(28, 49, 80, 0.5);
  padding: 20px;
  border-radius: var(--about-card-radius);
}
.page-about-preview-label,
.page-about-dataflow-label,
.page-about-cta-code {
  font-family: var(--about-font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin: 0 0 14px;
}
.page-about-chapter-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.page-about-chapter-list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 10px;
  border-radius: 6px;
  color: var(--color-rail-text);
  transition: background 0.2s ease, color 0.2s ease, padding-left 0.2s ease;
}
.page-about-chapter-list a:hover,
.page-about-chapter-list a:focus-visible {
  background: rgba(255, 107, 53, 0.14);
  color: #fff;
  padding-left: 14px;
}
.page-about-chapter-num {
  font-family: var(--about-font-mono);
  font-size: 12px;
  color: var(--color-accent);
}
.page-about-chapter-name {
  font-weight: 600;
}
.page-about-chapter-meta {
  margin-left: auto;
  font-size: 13px;
  color: var(--color-rail-text);
  opacity: 0.8;
}
.page-about-hero-metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 36px;
}
.page-about-metric {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 16px 14px;
  min-width: 0;
}
.page-about-metric-label {
  font-size: 13px;
  color: var(--color-rail-text);
  margin: 0 0 6px;
}
.page-about-metric-num {
  font-family: var(--about-font-mono);
  font-size: clamp(30px, 4vw, 40px);
  font-weight: 700;
  color: #fff;
  line-height: 1;
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}
.page-about-metric-unit {
  font-size: 0.5em;
  color: var(--color-accent);
  font-weight: 600;
}
.page-about-hero .breadcrumb {
  margin: 0 0 16px;
}
.page-about-hero .breadcrumb a {
  color: var(--color-rail-text);
}
.page-about-hero .breadcrumb a:hover,
.page-about-hero .breadcrumb a:focus-visible {
  color: var(--color-accent);
}
.page-about-hero .breadcrumb-current {
  color: #C9D4E6;
}
.page-about-hero .breadcrumb-sep {
  color: var(--color-border);
  margin: 0 4px;
}
.page-about-hero .btn {
  background: var(--color-accent);
  color: #fff;
  border: 1px solid var(--color-accent);
}
.page-about-hero .btn:hover,
.page-about-hero .btn:focus-visible {
  background: #FF8A4C;
  border-color: #FF8A4C;
}
.page-about-hero .btn-secondary {
  background: transparent;
  color: #fff;
  border: 1px solid rgba(169, 183, 211, 0.5);
}
.page-about-hero .btn-secondary:hover,
.page-about-hero .btn-secondary:focus-visible {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ===== Common Section ===== */
.page-about-section {
  padding: clamp(36px, 6vw, 76px) clamp(16px, 4vw, 56px) 0;
}
.page-about-section-head {
  margin-bottom: 28px;
}
.page-about-section-label {
  display: inline-block;
  font-family: var(--about-font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  background: rgba(255, 107, 53, 0.1);
  border: 1px solid rgba(255, 107, 53, 0.25);
  padding: 4px 12px;
  clip-path: var(--about-clip);
}
.page-about-section-head h2 {
  font-size: clamp(24px, 3.8vw, 36px);
  margin: 16px 0 0;
  max-width: 18em;
}

/* ===== We Are ===== */
.page-about-who-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
.page-about-who-copy p {
  margin-bottom: 1.1em;
  color: var(--color-text-primary);
}
.page-about-who-copy p + p {
  color: var(--color-mid)500;
}
.page-about-mission {
  position: relative;
  background: var(--color-deep);
  color: #fff;
  padding: 28px 24px;
  border-radius: var(--about-card-radius);
  clip-path: var(--about-clip);
}
.page-about-mission::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--color-accent);
}
.page-about-mission-code {
  font-family: var(--about-font-mono);
  font-size: 12px;
  color: var(--color-neon);
  display: block;
  margin-bottom: 12px;
}
.page-about-mission blockquote p {
  font-size: 18px;
  line-height: 1.6;
  color: #fff;
  margin: 0;
}
.page-about-mission-meta {
  margin-top: 18px;
  font-size: 13px;
  color: var(--color-rail-text);
  border-top: 1px solid rgba(169, 183, 211, 0.2);
  padding-top: 12px;
}

/* ===== Milestones / Timeline ===== */
.page-about-milestones {
  background: var(--color-mid);
  color: #fff;
  margin-top: clamp(24px, 5vw, 48px);
  padding-bottom: clamp(36px, 6vw, 72px);
}
.page-about-milestones .page-about-section-head h2 {
  color: #fff;
}
.page-about-milestones .page-about-section-label {
  background: rgba(57, 255, 20, 0.1);
  border-color: rgba(57, 255, 20, 0.3);
  color: var(--color-neon);
}
.page-about-milestone-fig {
  margin: 24px 0 36px;
}
.page-about-milestone-img {
  width: 100%;
  max-height: 400px;
  object-fit: cover;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}
.page-about-milestone-fig figcaption {
  font-size: 13px;
  color: var(--color-rail-text);
  margin-top: 8px;
  padding-left: 12px;
  border-left: 3px solid var(--color-accent);
}
.page-about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 24px;
}
.page-about-timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--color-accent) 0%, rgba(255, 107, 53, 0.35) 70%, transparent 100%);
}
.page-about-timeline-item {
  position: relative;
  margin: 0 0 28px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}
.page-about-timeline-marker {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 30px;
}
.page-about-marker-year {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background: var(--color-accent);
  color: #fff;
  font-family: var(--about-font-mono);
  font-size: 13px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 6px;
  white-space: nowrap;
  box-shadow: 0 0 0 4px rgba(255, 107, 53, 0.18);
  z-index: 2;
}
.page-about-marker-year::before {
  content: "";
  position: absolute;
  left: -12px;
  top: 50%;
  width: 12px;
  height: 2px;
  background: var(--color-accent);
  transform: translateY(-50%);
}
.page-about-marker-tip {
  font-size: 13px;
  color: var(--color-rail-text);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  white-space: nowrap;
}
.page-about-timeline-card {
  background: var(--color-deep);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 10px;
  padding: 16px 18px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}
.page-about-timeline-card h3 {
  color: #fff;
  font-size: 18px;
  margin: 0 0 8px;
}
.page-about-timeline-card p {
  color: var(--color-rail-text);
  font-size: 15px;
  margin: 0;
}
.page-about-timeline-item:hover .page-about-timeline-card,
.page-about-timeline-item:focus-within .page-about-timeline-card {
  border-color: var(--color-accent);
  transform: translateX(4px);
}
.page-about-timeline-item-current .page-about-marker-year {
  background: var(--color-neon);
  color: #06120A;
  box-shadow: 0 0 0 4px rgba(57, 255, 20, 0.15);
}
.page-about-timeline-item-current .page-about-marker-year::before {
  background: var(--color-neon);
}

/* ===== Certifications ===== */
.page-about-cert-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
.page-about-cert-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  overflow: hidden;
}
.page-about-cert-card details,
.page-about-cert-card summary {
  display: block;
}
.page-about-cert-summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 14px;
  padding: 20px 18px;
  cursor: pointer;
  list-style: none;
  transition: background 0.2s ease;
}
.page-about-cert-summary::-webkit-details-marker {
  display: none;
}
.page-about-cert-summary:hover,
.page-about-cert-card[open] .page-about-cert-summary {
  background: rgba(232, 237, 245, 0.6);
}
.page-about-cert-icon {
  font-family: var(--about-font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-deep);
  color: var(--color-accent);
  border: 1px solid var(--color-border);
  padding: 6px 8px;
  border-radius: 6px;
  min-width: 48px;
  text-align: center;
}
.page-about-cert-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.page-about-cert-info strong {
  font-size: 17px;
  color: var(--color-text-primary);
}
.page-about-cert-info small {
  font-size: 13px;
  color: var(--color-text-secondary);
  font-family: var(--about-font-mono);
  letter-spacing: 0.04em;
}
.page-about-cert-toggle {
  font-family: var(--about-font-mono);
  color: var(--color-accent);
  font-size: 20px;
  line-height: 1;
  transition: transform 0.2s ease;
}
.page-about-cert-card[open] .page-about-cert-toggle {
  transform: rotate(45deg);
}
.page-about-cert-body {
  padding: 0 18px 20px;
  border-top: 1px dashed var(--color-border);
  margin: 0 18px 0 74px;
  padding-left: 0;
  padding-top: 14px;
}
.page-about-cert-body p {
  font-size: 15px;
  color: var(--color-text-primary);
  margin: 0;
}
.page-about-cert-fig {
  margin-top: 28px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  flex-direction: column;
}
.page-about-cert-fig img {
  width: 100%;
  max-width: 600px;
  border-radius: 12px;
  object-fit: cover;
}
.page-about-cert-fig figcaption {
  font-size: 13px;
  color: var(--color-text-secondary);
  padding-left: 12px;
  border-left: 3px solid var(--color-neon);
}

/* ===== Partners ===== */
.page-about-partners {
  background: var(--color-light);
  padding-bottom: clamp(36px, 6vw, 72px);
  margin-top: clamp(24px, 5vw, 48px);
}
.page-about-partners .page-about-section-head h2 {
  color: var(--color-text-primary);
}
.page-about-partners-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
.page-about-partner-group {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 22px 20px;
  position: relative;
  overflow: hidden;
}
.page-about-partner-group::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--color-accent), transparent);
}
.page-about-partner-group h3 {
  font-size: 17px;
  margin: 0 0 14px;
  color: var(--color-text-primary);
}
.page-about-partner-group ul li {
  position: relative;
  padding: 6px 0 6px 18px;
  color: var(--color-text-secondary);
  font-size: 15px;
}
.page-about-partner-group ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  width: 8px;
  height: 8px;
  background: var(--color-accent);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}
.page-about-dataflow {
  margin-top: 32px;
  background: var(--color-deep);
  color: #fff;
  border-radius: 12px;
  padding: 24px 20px;
  clip-path: var(--about-clip);
}
.page-about-dataflow-steps {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.page-about-dataflow-steps li {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  padding: 8px 12px;
  color: #C9D4E6;
  font-size: 14px;
}
.page-about-dataflow-num {
  font-family: var(--about-font-mono);
  font-size: 12px;
  color: var(--color-accent);
}
.page-about-dataflow-note {
  margin-top: 16px;
  color: var(--color-rail-text);
  font-size: 14px;
  border-top: 1px dashed rgba(169, 183, 211, 0.2);
  padding-top: 12px;
}

/* ===== Team / Culture ===== */
.page-about-team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}
.page-about-team-fig {
  overflow: hidden;
  border-radius: 12px;
}
.page-about-team-fig img {
  width: 100%;
  max-height: 450px;
  object-fit: cover;
  transition: transform 0.25s ease;
}
.page-about-team-fig:hover img {
  transform: scale(1.02);
}
.page-about-team-fig figcaption {
  font-size: 13px;
  color: var(--color-text-secondary);
  padding: 8px 12px;
  background: var(--color-card);
  border-radius: 0 0 12px 12px;
}
.page-about-team-copy p {
  color: var(--color-text-primary);
}
.page-about-values {
  margin-top: 32px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.page-about-value-item {
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 14px 14px 14px 16px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: #fff;
}
.page-about-value-num {
  font-family: var(--about-font-mono);
  font-size: 13px;
  color: var(--color-accent);
  font-weight: 700;
  line-height: 1.4;
}
.page-about-value-item p {
  font-size: 14px;
  margin: 0;
  color: var(--color-text-secondary);
  line-height: 1.5;
}
.page-about-value-item strong {
  display: block;
  color: var(--color-text-primary);
  font-size: 15px;
  margin-bottom: 2px;
}

/* ===== CTA ===== */
.page-about-cta {
  padding: clamp(36px, 6vw, 72px) clamp(16px, 4vw, 56px) clamp(48px, 7vw, 96px);
}
.page-about-cta-inner {
  background: var(--color-deep);
  color: #fff;
  border-radius: 16px;
  padding: clamp(28px, 4vw, 44px);
  clip-path: var(--about-clip);
  position: relative;
  overflow: hidden;
}
.page-about-cta-inner::after {
  content: "";
  position: absolute;
  right: -40px;
  bottom: -40px;
  width: 160px;
  height: 160px;
  border: 2px solid var(--color-accent);
  border-radius: 50%;
  opacity: 0.25;
}
.page-about-cta-code {
  color: var(--color-neon);
}
.page-about-cta-inner h2 {
  color: #fff;
  font-size: clamp(22px, 3vw, 28px);
  margin: 0 0 12px;
}
.page-about-cta-inner > p {
  color: var(--color-rail-text);
  max-width: 36em;
}
.page-about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}
.page-about-cta .btn {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.page-about-cta .btn-secondary {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.35);
}
.page-about-cta .btn-ghost {
  background: transparent;
  color: #C9D4E6;
  border-color: transparent;
}
.page-about-cta .btn-ghost:hover,
.page-about-cta .btn-ghost:focus-visible {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* ===== 中等屏幕 ===== */
@media (min-width: 640px) {
  .page-about-hero-metrics {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about-who-grid {
    grid-template-columns: 1.2fr 0.8fr;
  }
  .page-about-who-copy {
    padding-right: 12px;
  }
  .page-about-timeline {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0;
  }
  .page-about-timeline-item {
    grid-template-columns: 180px 1fr;
    align-items: baseline;
    gap: 20px;
  }
  .page-about-timeline-item .page-about-timeline-marker {
    justify-content: flex-end;
    padding-top: 6px;
  }
  .page-about-cert-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about-cert-card:last-child {
    grid-column: 1 / -1;
  }
  .page-about-partners-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about-values {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about-team-grid {
    grid-template-columns: 0.85fr 1.15fr;
  }
  .page-about-cert-fig {
    flex-direction: row;
    align-items: center;
  }
  .page-about-cert-fig figcaption {
    max-width: 220px;
  }
}

/* ===== 桌面 ===== */
@media (min-width: 960px) {
  .page-about-hero-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 40px;
  }
  .page-about-hero-preview {
    margin-top: 0;
  }
  .page-about-hero-metrics {
    grid-column: 1 / -1;
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about-marker-tip {
    opacity: 0;
    transform: translateX(-6px);
  }
  .page-about-timeline-item:hover .page-about-marker-tip,
  .page-about-timeline-item:focus-within .page-about-marker-tip {
    opacity: 1;
    transform: translateX(0);
  }
  .page-about-cert-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about-cert-card:last-child {
    grid-column: auto;
  }
  .page-about-cert-body {
    margin-left: 74px;
  }
  .page-about-cta-inner {
    display: grid;
    grid-template-columns: auto 1fr;
    column-gap: 28px;
    align-items: center;
  }
  .page-about-cta-code {
    margin: 0;
  }
  .page-about-cta-inner h2 {
    margin: 0 0 6px;
  }
  .page-about-cta-actions {
    grid-column: 2;
    margin-top: 0;
  }
}

/* ===== 大桌面 ===== */
@media (min-width: 1280px) {
  .page-about-hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 56px;
  }
  .page-about-hero {
    padding: 72px 64px;
  }
  .page-about-section {
    padding-left: 64px;
    padding-right: 64px;
  }
  .page-about-who-grid {
    grid-template-columns: 1.3fr 0.7fr;
    gap: 48px;
  }
  .page-about-timeline-item {
    grid-template-columns: 240px 1fr;
  }
  .page-about-timeline-card {
    padding: 20px 24px;
  }
  .page-about-partners-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }
  .page-about-cta {
    padding-left: 64px;
    padding-right: 64px;
  }
}

/* ===== 动效偏好 ===== */
@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
  .page-about-timeline-item:hover .page-about-timeline-card,
  .page-about-timeline-item:focus-within .page-about-timeline-card {
    transform: none;
  }
}