.page-about {
  --about-rail: 260px;
  padding-bottom: 72px;
}

.page-about .about-masthead {
  display: grid;
  gap: 14px;
  padding: 32px 0 28px;
  border-bottom: 1px solid var(--line-blue);
}

.page-about .about-masthead h1 {
  margin: 0;
  font-size: 30px;
  line-height: 1.22;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ice);
  max-width: 20ch;
}

.page-about .about-masthead .lede {
  margin: 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .masthead-facts {
  list-style: none;
  margin: 6px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 16px;
}

.page-about .masthead-facts li {
  padding-left: 12px;
  border-left: 2px solid var(--line-blue);
}

.page-about .masthead-facts b {
  display: block;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--lime);
}

.page-about .masthead-facts span {
  display: block;
  margin-top: 2px;
  font-size: 13px;
  color: var(--mist);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-top: 28px;
}

.page-about .about-rail {
  display: grid;
  gap: 22px;
  min-width: 0;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line-blue);
}

.page-about .rail-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .rail-chapters {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px 12px;
}

.page-about .rail-chapters a {
  display: flex;
  gap: 8px;
  align-items: baseline;
  padding: 6px 0 6px 10px;
  border-left: 2px solid transparent;
  text-decoration: none;
  color: var(--mist);
  font-size: 13px;
  line-height: 1.5;
  transition: color 180ms ease-out, border-color 180ms ease-out;
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--lime);
}

.page-about .rail-chapters a:hover,
.page-about .rail-chapters a:focus-visible {
  color: var(--ice);
  border-left-color: var(--lime);
}

.page-about .rail-versions {
  list-style: none;
  margin: 0;
  padding: 0 0 0 16px;
  position: relative;
  display: flex;
  gap: 18px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.page-about .rail-versions::before {
  content: none;
}

.page-about .rail-versions li {
  position: relative;
  flex: 0 0 auto;
}

.page-about .rail-versions a {
  display: block;
  text-decoration: none;
  font-size: 12px;
  line-height: 1.4;
  color: var(--mist);
  padding-top: 12px;
  white-space: nowrap;
  transition: color 180ms ease-out;
}

.page-about .rail-versions a span {
  display: block;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 13px;
  color: var(--line-blue);
  transition: color 180ms ease-out;
}

.page-about .rail-versions li::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 8px;
  height: 2px;
  background: var(--line-blue);
  transition: background 180ms ease-out, box-shadow 180ms ease-out;
}

.page-about .rail-versions li:hover::before,
.page-about .rail-versions li:focus-within::before {
  background: var(--lime);
  box-shadow: 0 0 0 3px rgba(184, 255, 61, 0.18);
}

.page-about .rail-versions a:hover,
.page-about .rail-versions a:focus-visible,
.page-about .rail-versions li:hover a,
.page-about .rail-versions li:focus-within a {
  color: var(--ice);
}

.page-about .rail-versions li:hover a span,
.page-about .rail-versions li:focus-within a span {
  color: var(--lime);
}

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

.page-about .about-chapter {
  padding: 34px 0 10px;
  border-top: 1px solid var(--line-blue);
}

.page-about .about-chapter:first-child {
  border-top: none;
  padding-top: 4px;
}

.page-about .section-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 6px;
}

.page-about .section-head h2 {
  margin: 0;
  font-size: 24px;
  line-height: 1.3;
  font-weight: 700;
  color: var(--ice);
}

.page-about .section-number {
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
  color: transparent;
  -webkit-text-stroke: 1.4px var(--lime);
  text-stroke: 1.4px var(--lime);
}

.page-about .chapter-lead {
  margin: 8px 0 18px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--lime-soft);
  max-width: 30ch;
}

.page-about .prose p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ice);
  max-width: 68ch;
}

.page-about .prose p + p {
  color: var(--mist);
}

.page-about .chapter-note {
  margin: 18px 0 0;
  padding: 12px 16px;
  border-left: 2px solid var(--lime);
  background: var(--glass);
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-pause {
  margin: 26px 0 6px;
}

.page-about .about-pause img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-card);
  border: 1px solid var(--line-blue);
}

.page-about .about-pause .media__caption,
.page-about .audience__figure .media__caption {
  margin-top: 8px;
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--mist);
}

.page-about .stairs {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .step {
  position: relative;
  padding: 16px;
  background: var(--panel);
  border: 1px solid var(--line-blue);
  border-radius: var(--radius-card);
  transition: transform 180ms ease-out, border-color 180ms ease-out;
}

.page-about .step:hover,
.page-about .step:focus,
.page-about .step:focus-within {
  transform: translateY(-2px);
  border-color: var(--lime);
}

.page-about .step__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--lime);
}

.page-about .step__title {
  margin: 6px 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--ice);
}

.page-about .step__brief {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .step__detail {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  color: var(--signal);
}

.page-about .table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line-blue);
  border-radius: var(--radius-card);
  background: var(--panel);
  -webkit-overflow-scrolling: touch;
}

.page-about .version-table {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
  font-size: 14px;
}

.page-about .version-table caption {
  text-align: left;
}

.page-about .version-table thead th {
  padding: 12px 16px;
  background: var(--ink-black);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--mist);
  text-align: left;
}

.page-about .version-table tbody th,
.page-about .version-table tbody td {
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
  line-height: 1.65;
  color: var(--ice);
  border-top: 1px solid var(--line-blue);
}

.page-about .version-table tbody tr:nth-child(even) {
  background: rgba(10, 26, 47, 0.6);
}

.page-about .version-table tbody th {
  font-family: var(--font-mono);
  font-weight: 800;
  color: var(--lime);
  white-space: nowrap;
}

.page-about .version-table tbody td:nth-child(2) {
  font-family: var(--font-mono);
  color: var(--mist);
  white-space: nowrap;
}

.page-about .version-table tbody tr:hover {
  background: rgba(42, 84, 128, 0.35);
}

.page-about .version-table .is-key {
  color: var(--signal);
  font-weight: 600;
}

.page-about .team-bar {
  display: flex;
  height: 46px;
  margin: 18px 0 10px;
  border: 1px solid var(--line-blue);
  border-radius: 999px;
  overflow: hidden;
}

.page-about .team-bar__seg {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 800;
  color: var(--night);
}

.page-about .seg--edit {
  flex: 11 1 0;
  background: var(--lime);
}

.page-about .seg--data {
  flex: 5 1 0;
  background: var(--lime-soft);
}

.page-about .seg--tech {
  flex: 6 1 0;
  background: var(--mist);
}

.page-about .team-legend {
  margin: 0 0 20px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .team-cards {
  margin-top: 4px;
}

.page-about .team-card {
  padding: 18px;
}

.page-about .team-card__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--lime);
}

.page-about .team-card h3 {
  margin: 6px 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ice);
}

.page-about .team-card p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .audience {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  margin-bottom: 20px;
}

.page-about .audience__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.page-about .stat {
  padding: 14px 14px 12px;
  background: var(--panel);
  border: 1px solid var(--line-blue);
  border-radius: var(--radius-card);
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ice);
}

.page-about .stat__label {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  color: var(--mist);
}

.page-about .audience__figure {
  margin: 0;
}

.page-about .audience__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: var(--radius-card);
  border: 1px solid var(--line-blue);
}

.page-about .about-cta {
  margin-top: 34px;
  padding: 24px 20px;
  border-radius: var(--radius-glass);
}

.page-about .about-cta h2 {
  margin: 0 0 10px;
  font-size: 22px;
  line-height: 1.3;
  font-weight: 700;
  color: var(--ice);
}

.page-about .about-cta p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
  max-width: 62ch;
}

.page-about .cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

@media (min-width: 640px) {
  .page-about .about-masthead h1 {
    font-size: 38px;
  }

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

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

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

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

  .page-about .about-cta {
    padding: 28px 26px;
  }
}

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 48px;
    align-items: start;
    padding-top: 36px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    gap: 28px;
    padding-bottom: 0;
    border-bottom: none;
  }

  .page-about .rail-chapters {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  .page-about .rail-versions {
    display: grid;
    gap: 16px;
    overflow: visible;
    padding-left: 16px;
    padding-bottom: 0;
  }

  .page-about .rail-versions::before {
    content: "";
    position: absolute;
    left: 3px;
    top: 4px;
    bottom: 4px;
    width: 1px;
    background: var(--line-blue);
  }

  .page-about .rail-versions li::before {
    left: -16px;
    top: 4px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
  }

  .page-about .rail-versions a {
    padding-top: 0;
  }

  .page-about .rail-versions a span {
    display: inline;
    margin-right: 6px;
  }

  .page-about .about-chapter {
    padding: 40px 0 12px;
  }

  .page-about .section-head h2 {
    font-size: 28px;
  }

  .page-about .section-number {
    font-size: 44px;
  }

  .page-about .audience {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
    gap: 28px;
  }
}

@media (min-width: 1000px) {
  .page-about .stairs {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 10px;
    align-items: start;
  }

  .page-about .step:nth-child(2) {
    margin-top: 16px;
  }

  .page-about .step:nth-child(3) {
    margin-top: 32px;
  }

  .page-about .step:nth-child(4) {
    margin-top: 48px;
  }

  .page-about .step:nth-child(5) {
    margin-top: 64px;
  }

  .page-about .step__detail {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 200ms ease-out, opacity 200ms ease-out;
  }

  .page-about .step:hover .step__detail,
  .page-about .step:focus .step__detail,
  .page-about .step:focus-within .step__detail {
    max-height: 140px;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .step,
  .page-about .step__detail,
  .page-about .rail-chapters a,
  .page-about .rail-versions a,
  .page-about .rail-versions li::before {
    transition: none;
  }

  .page-about .step:hover,
  .page-about .step:focus,
  .page-about .step:focus-within {
    transform: none;
  }
}
<<<END>>>