.page-about {
  --about-grid: rgba(10, 31, 68, 0.12);
  --about-grid-soft: rgba(10, 31, 68, 0.07);
  --about-dark-grid: rgba(255, 255, 255, 0.1);
  --about-white: #FFFFFF;
  background: var(--c-cream);
  color: var(--c-ink);
}

.page-about .about-breadcrumbs {
  padding-top: var(--space-3);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-gray);
}

.page-about .breadcrumbs__current {
  color: var(--c-navy);
  font-weight: 700;
}

.page-about .about-intro {
  position: relative;
  margin-top: var(--space-4);
  background:
    linear-gradient(var(--about-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-grid) 1px, transparent 1px);
  background-size: 24px 24px;
  border-top: 2px solid var(--c-navy);
  border-bottom: 6px solid var(--c-navy);
  padding: var(--space-5) 0 var(--space-4);
}

.page-about .about-intro__inner {
  display: grid;
  gap: var(--space-3);
}

.page-about .about-intro__meta-line {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-orange);
  text-transform: uppercase;
}

.page-about .about-intro__tagline {
  color: var(--c-gray);
}

.page-about .about-intro__title {
  font-family: var(--font-heading);
  font-size: 30px;
  line-height: 1.18;
  letter-spacing: 0.01em;
  margin: var(--space-2) 0 var(--space-2);
  max-width: 14em;
}

.page-about .about-intro__sub {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-orange);
  margin: 0;
  letter-spacing: 0.06em;
}

.page-about .about-intro__facts {
  display: grid;
  grid-template-columns: repeat(3, auto);
  gap: var(--space-3);
  margin: var(--space-3) 0 0;
  padding: var(--space-3) 0 0;
  border-top: 1px solid var(--about-grid);
}

.page-about .about-intro__fact {
  background: var(--c-white);
  padding: var(--space-2) var(--space-2);
  border-left: 4px solid var(--c-orange);
  box-shadow: 3px 3px 0 rgba(10, 31, 68, 0.06);
}

.page-about .about-intro__fact dt {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-gray);
}

.page-about .about-intro__fact dd {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  margin: 0;
  color: var(--c-navy);
}

.page-about .about-intro__note {
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-gray);
  border-left: 2px solid var(--c-navy);
  padding-left: var(--space-3);
  margin: var(--space-2) 0 0;
}

.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  padding-top: var(--space-5);
  padding-bottom: var(--space-6);
}

.page-about .chapter-nav {
  background: var(--c-white);
  border: 1px solid var(--about-grid);
  padding: var(--space-3);
  box-shadow: 4px 4px 0 rgba(10, 31, 68, 0.05);
}

.page-about .chapter-nav__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-gray);
  border-bottom: 1px solid var(--about-grid);
  padding-bottom: var(--space-2);
}

.page-about .chapter-nav__list {
  list-style: none;
  margin: var(--space-2) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
}

.page-about .chapter-nav__item {
  margin: 0;
}

.page-about .chapter-nav__link {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-1);
  text-decoration: none;
  color: var(--c-navy);
  font-size: 15px;
  font-weight: 700;
  padding: var(--space-1) var(--space-1);
  border-bottom: 2px solid transparent;
  transition: background var(--duration) var(--ease-out), color var(--duration) var(--ease-out);
}

.page-about .chapter-nav__link:hover,
.page-about .chapter-nav__link:focus-visible {
  background: var(--c-cream);
  border-bottom-color: var(--c-orange);
  outline: none;
}

.page-about .chapter-nav__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  color: var(--c-orange);
}

.page-about .chapter-nav__btn {
  margin-top: var(--space-3);
  display: block;
  text-align: center;
}

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

.page-about .about-chapter {
  position: relative;
  scroll-margin-top: 96px;
  padding-bottom: var(--space-5);
  margin-bottom: var(--space-5);
}

.page-about .about-chapter::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 20px;
  background: linear-gradient(90deg, transparent 0 16px, var(--about-grid) 16px 17px, transparent 17px 32px);
  background-size: 32px 100%;
}

.page-about .about-chapter--dark::after {
  content: none;
}

.page-about .about-chapter--dark {
  background-color: var(--c-navy);
  background-image: repeating-linear-gradient(90deg, transparent 0 42px, var(--about-dark-grid) 43px 44px);
  color: var(--c-white);
  padding: var(--space-5) var(--space-4);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), 0 100%);
  margin-bottom: var(--space-6);
}

.page-about .chapter-head {
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
  margin-bottom: var(--space-4);
}

.page-about .chapter-head__idx {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  color: var(--c-orange);
  font-size: 28px;
  line-height: 1;
  padding-top: 2px;
}

.page-about .chapter-head__rule {
  display: inline-block;
  width: 48px;
  height: 4px;
  background: var(--c-orange);
  transform: skewX(-18deg);
}

.page-about .chapter-head__title {
  font-family: var(--font-heading);
  font-size: 28px;
  line-height: 1.2;
  margin: 0 0 var(--space-1);
}

.page-about .chapter-head__desc {
  font-size: 15px;
  color: var(--c-gray);
  margin: 0;
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.page-about .chapter-head--light .chapter-head__desc {
  color: rgba(255, 255, 255, 0.7);
}

.page-about .chapter-head--light .chapter-head__idx {
  color: var(--c-orange);
}

.page-about .story-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  align-items: center;
}

.page-about .story-copy p {
  margin-bottom: var(--space-3);
}

.page-about .about-photo {
  margin: var(--space-4) 0 0;
}

.page-about .photo-frame {
  background: linear-gradient(var(--about-grid-soft) 1px, transparent 1px), linear-gradient(90deg, var(--about-grid-soft) 1px, transparent 1px);
  background-size: 16px 16px;
}

.page-about .photo-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
}

.page-about .about-photo__cap {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-gray);
  margin: var(--space-1) 0 0;
  padding-left: var(--space-2);
  border-left: 3px solid var(--c-orange);
}

.page-about .mechanism-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

.page-about .mechanism-card {
  background: var(--c-white);
  color: var(--c-ink);
  padding: var(--space-4);
  border-top: 4px solid var(--c-orange);
  position: relative;
}

.page-about .mechanism-card::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, transparent 0 50%, var(--c-cream) 50% 100%);
  pointer-events: none;
}

.page-about .mechanism-card__title {
  font-family: var(--font-heading);
  font-size: 22px;
  line-height: 1.25;
  margin: 0 0 var(--space-1);
}

.page-about .mechanism-card__lead {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-orange);
  margin: 0 0 var(--space-3);
  letter-spacing: 0.04em;
}

.page-about .mechanism-card__text {
  font-size: 16px;
  line-height: 1.8;
  margin-bottom: var(--space-3);
}

.page-about .mechanism-steps {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .mechanism-step {
  border-left: 2px solid var(--c-navy);
  padding-left: var(--space-3);
  margin-bottom: var(--space-3);
}

.page-about .mechanism-step__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-orange);
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: var(--space-1);
}

.page-about .mechanism-step p {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
}

.page-about .mechanism-sync {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: 14px;
  background: var(--c-cream);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius);
  color: var(--c-navy);
}

.page-about .stat-grid {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 2px solid var(--c-navy);
  background: var(--c-white);
}

.page-about .stat-cell {
  position: relative;
  padding: var(--space-3);
  border: 1px solid var(--about-grid);
  border-top-width: 0;
  border-left: 4px solid var(--c-orange);
}

.page-about .stat-cell:nth-child(3n + 2) {
  border-left-color: var(--c-neon);
}

.page-about .stat-cell__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-gray);
  margin-bottom: var(--space-1);
}

.page-about .stat-cell__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 34px;
  line-height: 1.1;
  font-weight: 700;
  color: var(--c-navy);
}

.page-about .stat-cell__note {
  display: block;
  font-size: 13px;
  color: var(--c-gray);
  margin-top: var(--space-1);
}

.page-about .scale-note {
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
  background: var(--c-navy);
  color: var(--c-white);
  padding: var(--space-4);
  margin-top: var(--space-4);
  clip-path: polygon(0 0, 100% 0, calc(100% - 20px) 100%, 0 100%);
}

.page-about .scale-note__index {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-neon);
  border: 1px solid var(--c-neon);
  padding: 2px 6px;
  background: rgba(57, 255, 20, 0.08);
}

.page-about .scale-note p {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
}

.page-about .scale-note strong {
  color: var(--c-neon);
  font-weight: 700;
}

.page-about .timeline {
  margin-top: var(--space-4);
}

.page-about .timeline__item {
  border-left: 2px solid var(--c-navy);
  margin: var(--space-3) 0;
  padding-left: var(--space-3);
  background: var(--c-white);
  padding-top: var(--space-2);
  padding-right: var(--space-2);
  padding-bottom: var(--space-2);
}

.page-about .timeline__head {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  list-style: none;
  cursor: pointer;
  font-weight: 700;
  color: var(--c-navy);
}

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

.page-about .timeline__year {
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--c-orange);
  color: var(--c-white);
  padding: 2px 8px;
  white-space: nowrap;
}

.page-about .timeline__toggle {
  margin-left: auto;
  flex-shrink: 0;
  font-family: var(--font-mono);
  color: var(--c-orange);
  font-size: 18px;
}

.page-about .timeline__toggle::before {
  content: "+";
}

.page-about .timeline__item[open] .timeline__toggle::before {
  content: "–";
}

.page-about .timeline__body {
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-gray);
  padding-top: var(--space-2);
}

.page-about .timeline__body p {
  margin: 0;
}

.page-about .tech-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  align-items: center;
}

.page-about .tech-list {
  list-style: none;
  margin: var(--space-3) 0 0;
  padding: 0;
  border-top: 1px solid var(--about-grid);
}

.page-about .tech-list li {
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--about-grid);
  font-size: 15px;
  line-height: 1.6;
  padding-left: var(--space-3);
  position: relative;
}

.page-about .tech-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 8px;
  height: 8px;
  background: var(--c-orange);
  transform: skewX(-15deg);
}

.page-about .tech-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  border: 2px solid var(--c-navy);
  padding: var(--space-2) var(--space-3);
  margin-top: var(--space-3);
  background: var(--c-white);
  font-weight: 700;
  font-size: 15px;
  color: var(--c-navy);
}

.page-about .tech-badge__num {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--c-neon);
  background: var(--c-navy);
  padding: 4px 8px;
}

.page-about .team-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  align-items: center;
}

.page-about .team-copy .prose p {
  font-size: 16px;
  line-height: 1.9;
}

.page-about .team-bars {
  margin-top: var(--space-3);
}

.page-about .team-bar {
  margin: var(--space-3) 0;
}

.page-about .team-bar__label,
.page-about .team-bar__value {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-navy);
}

.page-about .team-bar__value {
  float: right;
  font-weight: 700;
}

.page-about .team-bar__track {
  clear: both;
  height: 10px;
  background: rgba(10, 31, 68, 0.1);
  position: relative;
  overflow: hidden;
}

.page-about .team-bar__track span {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  background: var(--c-navy);
  transform: skewX(-10deg);
  transform-origin: left center;
}

.page-about .team-bar:nth-child(2) .team-bar__track span {
  background: var(--c-orange);
}

.page-about .team-bar:nth-child(3) .team-bar__track span {
  background: var(--c-neon);
}

.page-about .about-cta {
  background: var(--c-navy);
  color: var(--c-white);
  padding: var(--space-6) 0;
  position: relative;
  overflow: hidden;
  margin-top: var(--space-4);
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  right: -5%;
  top: -20%;
  width: 55%;
  height: 140%;
  background: linear-gradient(160deg, transparent 0 78%, var(--c-orange) 80% 100%);
  transform: skewX(-15deg);
  pointer-events: none;
}

.page-about .about-cta__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-cta__index {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--c-neon);
  margin-bottom: var(--space-2);
}

.page-about .about-cta__title {
  font-family: var(--font-heading);
  font-size: 28px;
  line-height: 1.2;
  margin: 0 0 var(--space-2);
  max-width: 14em;
}

.page-about .about-cta__desc {
  font-size: 16px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.78);
  margin-bottom: var(--space-4);
  max-width: 32em;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.page-about .about-cta .btn--primary {
  background: var(--c-orange);
  border-color: var(--c-orange);
  color: var(--c-white);
}

.page-about .about-cta .btn--outline {
  border-color: var(--c-white);
  color: var(--c-white);
}

.page-about .about-cta .btn--outline:hover,
.page-about .about-cta .btn--outline:focus-visible {
  background: rgba(255, 255, 255, 0.12);
}

@media (min-width: 700px) {
  .page-about .about-intro__title {
    font-size: 38px;
  }

  .page-about .about-intro__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.8fr);
    gap: var(--space-4);
  }

  .page-about .about-intro__side {
    grid-column: 1 / -1;
  }

  .page-about .about-intro__facts {
    grid-column: 1 / 2;
  }

  .page-about .about-intro__note {
    grid-column: 2 / 3;
    grid-row: 2;
  }

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

  .page-about .chapter-head__title {
    font-size: 30px;
  }

  .page-about .about-cta__title {
    font-size: 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-intro {
    padding: var(--space-6) 0 var(--space-5);
  }

  .page-about .about-intro__title {
    font-size: 44px;
    max-width: 10em;
  }

  .page-about .about-intro__inner {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
  }

  .page-about .about-intro__side {
    grid-column: 1 / 2;
  }

  .page-about .about-intro__facts {
    grid-column: 2 / 3;
    grid-row: 1;
    grid-template-columns: 1fr;
    border-top: 0;
    border-left: 1px solid var(--about-grid);
    margin-top: 0;
  }

  .page-about .about-intro__note {
    grid-column: 2 / 3;
    grid-row: 2;
    margin-top: var(--space-2);
  }

  .page-about .about-body {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: var(--space-5);
    align-items: start;
  }

  .page-about .chapter-nav__sticky {
    position: sticky;
    top: 96px;
  }

  .page-about .chapter-nav__list {
    flex-direction: column;
    gap: var(--space-1);
  }

  .page-about .chapter-nav__link {
    width: 100%;
  }

  .page-about .story-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: var(--space-5);
  }

  .page-about .about-photo {
    margin-top: 0;
  }

  .page-about .mechanism-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: var(--space-4);
  }

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

  .page-about .tech-layout {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .team-layout {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-cta {
    padding: var(--space-6) 0;
  }

  .page-about .about-cta__title {
    font-size: 36px;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .page-about .about-chapter:target .chapter-head__title {
    color: var(--c-orange);
    transition: color 360ms var(--ease-out);
  }
}