.page-about {
  --about-rail: 96px;
  --about-tick: 10px;
}

.page-about h1 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(30px, 7.2vw, 54px);
  line-height: 1.16;
  letter-spacing: -0.03em;
  color: var(--ink);
}

.page-about .about-hero {
  display: grid;
  gap: 32px;
  padding: 8px 0 48px;
}

.page-about .hero-axis {
  display: flex;
  flex-direction: column;
  gap: 18px;
  position: relative;
  padding-left: 18px;
  border-left: 3px solid var(--maple);
}

.page-about .axis-coord {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ice);
  word-break: break-word;
}

.page-about .hero-axis .lede {
  margin: 0;
  max-width: 40em;
  color: var(--ink);
}

.page-about .hero-points {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .hero-points li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.65;
  color: var(--ink);
}

.page-about .hero-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: var(--about-tick);
  height: var(--about-tick);
  background: var(--pine);
  border-radius: 2px;
}

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

.page-about .hero-figure {
  border: var(--border-hard);
  border-radius: var(--radius-panel);
  box-shadow: var(--shadow-hard);
  background: var(--ice-soft);
  overflow: hidden;
}

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

.page-about .hero-figure .media-frame-caption,
.page-about .method-figure .media-frame-caption,
.page-about .crew-figure .media-frame-caption {
  display: block;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--pine);
  background: var(--snow);
  border-top: 2px solid var(--ink);
}

.page-about .about-section {
  padding: 44px 0;
  border-top: 1px solid var(--fog);
}

.page-about .section-head {
  display: grid;
  gap: 10px;
  margin-bottom: 28px;
  max-width: 62ch;
}

.page-about .section-head .section-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(24px, 5vw, 36px);
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .section-sub {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
}

/* 方法章节 */
.page-about .method-section {
  background: var(--paper);
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
}

.page-about .method-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr;
}

.page-about .method-card {
  position: relative;
  display: grid;
  gap: 8px;
  padding: 20px 18px 18px;
  background: var(--snow);
  border: var(--border-hard);
  border-radius: 14px;
  box-shadow: var(--shadow-soft);
}

.page-about .method-card h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.01em;
  color: var(--pine);
}

.page-about .method-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .method-index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--maple);
}

.page-about .method-card .tag {
  justify-self: start;
  margin-top: 4px;
}

.page-about .method-lower {
  display: grid;
  gap: 24px;
  margin-top: 26px;
}

.page-about .method-figure {
  margin: 0;
  border: var(--border-hard);
  border-radius: 14px;
  background: var(--ice-soft);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}

.page-about .method-folds {
  display: grid;
  gap: 10px;
  align-content: start;
}

.page-about .fold {
  background: var(--snow);
  border: 2px solid var(--pine);
  border-radius: 12px;
  padding: 0 16px;
  transition: box-shadow 180ms ease, border-color 180ms ease;
}

.page-about .fold[open] {
  box-shadow: 4px 4px 0 0 rgba(31, 59, 50, 0.22);
}

.page-about .fold summary {
  cursor: pointer;
  padding: 14px 0;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 15px;
  color: var(--pine);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about .fold summary::-webkit-details-marker {
  display: none;
}

.page-about .fold summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--maple);
  line-height: 1;
}

.page-about .fold[open] summary::before {
  content: "–";
}

.page-about .fold summary:focus-visible {
  outline: 3px solid var(--maple);
  outline-offset: 2px;
  border-radius: 4px;
}

.page-about .fold p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

/* 时间轴章节 */
.page-about .timeline-section {
  background: var(--pine);
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  color: var(--snow);
}

.page-about .section-head--invert .section-title {
  color: var(--snow);
}

.page-about .section-head--invert .section-sub {
  color: var(--ice-soft);
}

.page-about .section-head--invert .eyebrow {
  color: var(--amber);
}

.page-about .timeline {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  border-top: 1px solid rgba(220, 233, 239, 0.32);
}

.page-about .timeline-stop {
  display: grid;
  gap: 6px;
  padding: 20px 0 22px 18px;
  border-bottom: 1px solid rgba(220, 233, 239, 0.22);
  border-left: 3px solid rgba(220, 233, 239, 0.3);
  transition: border-color 160ms ease, background 160ms ease;
}

.page-about .timeline-stop:hover,
.page-about .timeline-stop:focus-within {
  border-left-color: var(--maple);
  background: rgba(220, 233, 239, 0.06);
}

.page-about .stop-year {
  font-family: var(--font-mono);
  font-size: 20px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.page-about .stop-title {
  margin: 0 0 6px;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 18px;
  color: var(--snow);
}

.page-about .stop-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ice-soft);
  max-width: 62ch;
}

.page-about .about-metrics {
  margin-top: 32px;
}

.page-about .about-metrics .metric {
  background: var(--snow);
  border: 2px solid var(--ink);
  border-radius: 12px;
  padding: 16px 14px;
  box-shadow: 4px 4px 0 0 var(--maple);
}

.page-about .about-metrics .metric-value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(20px, 4.4vw, 26px);
  letter-spacing: -0.01em;
  color: var(--pine);
}

.page-about .about-metrics .metric-label {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink);
}

/* 团队章节 */
.page-about .crew-section {
  background: var(--ice-soft);
}

.page-about .crew-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr;
}

.page-about .crew-card {
  display: grid;
  gap: 8px;
  padding: 20px 18px;
  background: var(--snow);
  border: var(--border-hard);
  border-radius: 14px;
  box-shadow: var(--shadow-soft);
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.page-about .crew-card:hover,
.page-about .crew-card:focus-within {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-hard);
}

.page-about .crew-count {
  font-family: var(--font-mono);
  font-size: 34px;
  line-height: 1;
  color: var(--maple);
}

.page-about .crew-card h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 19px;
  color: var(--pine);
}

.page-about .crew-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink);
}

.page-about .crew-tags {
  margin: 6px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.page-about .crew-tags li {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  padding: 4px 9px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--ice);
  color: var(--pine);
  background: var(--ice-soft);
}

.page-about .crew-lower {
  display: grid;
  gap: 22px;
  margin-top: 28px;
}

.page-about .crew-figure {
  margin: 0;
  border: var(--border-hard);
  border-radius: 14px;
  background: var(--paper);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}

.page-about .crew-note {
  display: grid;
  gap: 12px;
  align-content: start;
  padding: 20px 18px;
  background: var(--snow);
  border: 2px dashed var(--pine);
  border-radius: 14px;
}

.page-about .crew-note h3 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: 22px;
  letter-spacing: -0.02em;
  color: var(--pine);
}

.page-about .crew-note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .crew-note .btn {
  justify-self: start;
}

/* 服务原则 */
.page-about .principle-section {
  background: var(--snow);
}

.page-about .principle-list {
  display: grid;
  gap: 0;
  border-top: 2px solid var(--ink);
}

.page-about .principle {
  display: grid;
  gap: 6px;
  padding: 20px 0;
  border-bottom: 1px solid var(--fog);
}

.page-about .principle-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--maple);
}

.page-about .principle h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 18px;
  color: var(--pine);
}

.page-about .principle p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
  max-width: 60ch;
}

.page-about .route-strip {
  margin-top: 34px;
  padding: 20px 18px;
  background: var(--paper);
  border: var(--border-hard);
  border-radius: 14px;
  box-shadow: var(--shadow-soft);
}

.page-about .route-lead {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--pine);
}

.page-about .route-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .route-list a {
  display: block;
  padding: 12px 14px;
  background: var(--snow);
  border: 2px solid var(--ink);
  border-radius: 10px;
  color: var(--ink);
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  transition: background 140ms ease, color 140ms ease, transform 140ms ease;
}

.page-about .route-list a:hover,
.page-about .route-list a:focus-visible {
  background: var(--maple);
  color: #FFFFFF;
  transform: translate(-2px, -2px);
}

.page-about .route-list a:focus-visible {
  outline: 3px solid var(--pine);
  outline-offset: 2px;
}

@media (min-width: 720px) {
  .page-about .method-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .method-card--wide {
    grid-column: span 2;
  }

  .page-about .crew-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .timeline-stop {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 18px;
    align-items: start;
    padding-left: 22px;
  }

  .page-about .route-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-hero {
    grid-template-columns: 7fr 5fr;
    align-items: start;
    gap: 40px;
    padding: 16px 0 64px;
  }

  .page-about .hero-axis {
    padding-left: 24px;
  }

  .page-about .about-section {
    padding: 60px 0;
  }

  .page-about .method-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .method-card--wide {
    grid-column: span 3;
  }

  .page-about .method-lower {
    grid-template-columns: 7fr 5fr;
    align-items: start;
    gap: 30px;
  }

  .page-about .crew-lower {
    grid-template-columns: 6fr 6fr;
    align-items: start;
    gap: 30px;
  }

  .page-about .principle-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 36px;
  }

  .page-about .route-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .crew-card,
  .page-about .route-list a,
  .page-about .timeline-stop,
  .page-about .fold {
    transition: none;
  }

  .page-about .crew-card:hover,
  .page-about .crew-card:focus-within,
  .page-about .route-list a:hover,
  .page-about .route-list a:focus-visible {
    transform: none;
  }
}