.page-about {
  --ab-rail: 200px;
  --ab-card: rgba(14, 17, 16, .86);
  background:
    radial-gradient(1100px 520px at 82% -8%, rgba(77, 224, 192, .10), transparent 62%),
    radial-gradient(900px 460px at 4% 2%, rgba(198, 255, 61, .07), transparent 60%),
    var(--c-ink);
  color: var(--c-paper);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about .ab-hero {
  padding-block: clamp(20px, 4vw, 40px) clamp(40px, 7vw, 84px);
}

.page-about .ab-hero-grid {
  display: grid;
  gap: clamp(26px, 4vw, 40px);
  margin-top: clamp(22px, 4vw, 40px);
}

.page-about .ab-hero-copy {
  min-width: 0;
}

.page-about .ab-kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.page-about .ab-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(36px, 7.6vw, 74px);
  line-height: 1.04;
  letter-spacing: -.012em;
  color: var(--c-paper);
  text-wrap: balance;
}

.page-about .ab-lead {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.6vw, 17.5px);
  line-height: 1.9;
  color: #CBD8D2;
}

.page-about .ab-hero-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 9px;
  max-width: 58ch;
}

.page-about .ab-hero-list li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-note);
}

.page-about .ab-hero-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 10px;
  height: 1px;
  background: var(--c-lime);
}

.page-about .ab-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .ab-board {
  border: var(--hair);
  border-radius: var(--r-md);
  background: linear-gradient(180deg, rgba(18, 49, 40, .92), rgba(14, 17, 16, .94));
  box-shadow: var(--shadow-soft);
  padding: 18px clamp(16px, 3vw, 24px) 20px;
}

.page-about .ab-board-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: 0 0 12px;
  padding-bottom: 12px;
  border-bottom: var(--hair);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-note);
}

.page-about .ab-board-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: baseline;
  padding: 10px 0;
  border-bottom: 1px dashed rgba(42, 59, 53, .9);
}

.page-about .ab-board-row:last-child {
  border-bottom: 0;
  padding-bottom: 2px;
}

.page-about .ab-board-row .field-label {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--c-note);
}

.page-about .ab-board-row .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(15px, 2vw, 17px);
  color: var(--c-lime);
  white-space: nowrap;
}

.page-about .ab-chapter {
  padding-block: clamp(40px, 7vw, 88px);
  border-top: var(--hair);
}

.page-about .ab-chapter-grid {
  display: grid;
  gap: clamp(18px, 3vw, 28px);
}

.page-about .ab-chapter-aside .ab-index {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(38px, 8vw, 76px);
  line-height: .88;
  letter-spacing: -.05em;
  color: var(--c-lime);
}

.page-about .ab-chapter-aside .field-label {
  margin: 10px 0 0;
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-note);
}

.page-about .ab-chapter-body {
  min-width: 0;
}

.page-about .ab-title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(25px, 4.2vw, 40px);
  line-height: 1.16;
  letter-spacing: -.005em;
  color: var(--c-paper);
}

.page-about .ab-body-text,
.page-about .ab-chapter-body .prose p {
  margin: 0 0 16px;
  max-width: 72ch;
  font-size: 16px;
  line-height: 1.9;
  color: #D2DDD7;
}

.page-about .ab-chapter-body .prose p:last-child {
  margin-bottom: 0;
}

.page-about .ab-split {
  display: grid;
  gap: 26px;
}

.page-about .ab-figure {
  margin: 0;
}

.page-about .ab-figure--top {
  margin-bottom: 26px;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .ab-figure .media-frame {
  border: var(--hair);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--c-moss);
}

.page-about .ab-figure .media-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .02em;
  color: var(--c-dim);
}

.page-about .ab-crew {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.page-about .ab-crew-card {
  border: var(--hair);
  border-radius: var(--r-md);
  background: var(--ab-card);
  padding: 20px 18px 22px;
  transition: border-color .2s var(--ease), background-color .2s var(--ease), transform .2s var(--ease);
}

.page-about .ab-crew-card:hover,
.page-about .ab-crew-card:focus-within {
  border-color: rgba(198, 255, 61, .45);
  background-color: rgba(18, 49, 40, .82);
  transform: translateY(-2px);
}

.page-about .ab-crew-num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(34px, 6vw, 44px);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--c-lime);
}

.page-about .ab-crew-num small {
  margin-left: 6px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-note);
}

.page-about .ab-crew-card h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: .01em;
  color: var(--c-paper);
}

.page-about .ab-crew-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--c-note);
}

.page-about .ab-note {
  margin: 22px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--c-amber);
  max-width: 68ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: #B9C8C1;
}

.page-about .ab-track {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .ab-track::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--c-cyan), var(--c-line) 28%, var(--c-line));
}

.page-about .ab-track li {
  position: relative;
  padding: 0 0 26px 38px;
}

.page-about .ab-track li:last-child {
  padding-bottom: 0;
}

.page-about .ab-track li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 1px solid var(--c-line);
  background: var(--c-carbon);
}

.page-about .ab-track li:last-child::before {
  background: var(--c-lime);
  border-color: var(--c-lime);
  box-shadow: 0 0 0 4px rgba(198, 255, 61, .12);
}

.page-about .ab-track-year {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: .16em;
  color: var(--c-cyan);
}

.page-about .ab-track h3 {
  margin: 6px 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .01em;
  color: var(--c-paper);
}

.page-about .ab-track li p {
  margin: 0;
  max-width: 66ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--c-note);
}

.page-about .ab-steps {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  border-top: var(--hair);
}

.page-about .ab-step {
  border-bottom: var(--hair);
}

.page-about .ab-step summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 4px;
  cursor: pointer;
  list-style: none;
  transition: background-color .18s var(--ease);
}

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

.page-about .ab-step summary:hover {
  background-color: rgba(42, 59, 53, .28);
}

.page-about .ab-step summary .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--c-amber);
}

.page-about .ab-step-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .01em;
  color: var(--c-paper);
}

.page-about .ab-step summary::after {
  content: "展开";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--c-dim);
}

.page-about .ab-step[open] summary::after {
  content: "收起";
  color: var(--c-amber);
}

.page-about .ab-step-body {
  padding: 0 4px 18px;
}

.page-about .ab-step-body p {
  margin: 0;
  max-width: 68ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--c-note);
}

.page-about .ab-fieldset {
  display: grid;
  gap: 1px;
  margin-top: 26px;
  border: var(--hair);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--c-line);
}

.page-about .ab-field {
  background: var(--c-carbon);
  padding: 14px 16px;
}

.page-about .ab-field .field-label {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--c-note);
}

.page-about .ab-field .field-value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 14.5px;
  line-height: 1.5;
  color: var(--c-lime-soft);
  overflow-wrap: anywhere;
}

.page-about .ab-stats {
  display: grid;
  gap: 1px;
  margin-top: 24px;
  border: var(--hair);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--c-line);
}

.page-about .ab-stat {
  background: var(--c-carbon);
  padding: 18px 16px 20px;
}

.page-about .ab-stat-num {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 4.4vw, 32px);
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--c-lime);
}

.page-about .ab-stat-num span {
  margin-left: 4px;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--c-note);
}

.page-about .ab-stat .field-label {
  margin: 0;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--c-note);
}

.page-about .ab-cta {
  margin-top: 30px;
  padding: clamp(20px, 4vw, 30px);
  border: 1px solid rgba(198, 255, 61, .28);
  border-radius: var(--r-md);
  background:
    linear-gradient(135deg, rgba(18, 49, 40, .92), rgba(14, 17, 16, .96) 62%);
  display: grid;
  gap: 20px;
}

.page-about .ab-cta-copy h3 {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(22px, 3.4vw, 28px);
  line-height: 1.2;
  color: var(--c-paper);
}

.page-about .ab-cta-copy p {
  margin: 0;
  max-width: 52ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: #C3D1CA;
}

.page-about .ab-cta-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 20px;
}

.page-about .ab-more {
  margin: 24px 0 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  font-size: 13.5px;
  color: var(--c-dim);
}

@media (min-width: 640px) {
  .page-about .ab-fieldset {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .ab-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: clamp(26px, 4vw, 48px);
    align-items: start;
  }

  .page-about .ab-crew {
    grid-template-columns: 1.12fr .96fr .9fr;
    align-items: start;
    gap: 16px;
  }

  .page-about .ab-crew-card:nth-child(2) {
    margin-top: 26px;
  }

  .page-about .ab-crew-card:nth-child(3) {
    margin-top: 52px;
  }

  .page-about .ab-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, .8fr);
    gap: clamp(40px, 5vw, 72px);
    align-items: start;
  }

  .page-about .ab-board {
    margin-top: 8px;
  }

  .page-about .ab-chapter-grid {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
  }

  .page-about .ab-chapter-aside {
    position: sticky;
    top: 104px;
    align-self: start;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-crew-card {
    transition: none;
  }

  .page-about .ab-crew-card:hover,
  .page-about .ab-crew-card:focus-within {
    transform: none;
  }
}