.page-about {
  background: var(--abyss);
  color: var(--white);
  font-family: var(--font-body);
  line-height: 1.75;
  overflow-x: hidden;
}

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

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4.5vw, 48px) 0 clamp(40px, 6vw, 80px);
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(120% 90% at 82% -10%, rgba(53, 242, 208, 0.12), transparent 62%),
    radial-gradient(90% 80% at 8% 110%, rgba(255, 90, 54, 0.09), transparent 65%),
    var(--abyss);
}

.page-about .about-hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--line-faint) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-faint) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.85), transparent 90%);
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.85), transparent 90%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  align-items: center;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5vw, 56px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  margin: 10px 0 0;
  color: var(--white);
}

.page-about .about-hero .section-lede {
  margin-top: 16px;
  max-width: 44ch;
  color: var(--mist);
}

.page-about .hero-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 18px;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
}

.page-about .hero-metrics > div {
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(20px, 2.6vw, 28px);
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .stat-label {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--mist);
}

.page-about .hero-visual {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
  box-shadow: var(--shadow-panel);
}

.page-about .hero-visual::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 26px;
  height: 26px;
  border-top: 2px solid var(--cyan);
  border-left: 2px solid var(--cyan);
  pointer-events: none;
  z-index: 1;
}

.page-about .hero-visual img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .hero-visual figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .about-shell {
  display: grid;
  gap: clamp(22px, 3.5vw, 52px);
  padding-top: clamp(32px, 5vw, 64px);
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .chapter-nav__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--mist);
}

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

.page-about .chapter-nav a {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 6px 10px;
  border-bottom: 1px solid var(--line-soft);
  color: var(--mist);
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .chapter-nav a:hover,
.page-about .chapter-nav a:focus-visible {
  color: var(--white);
  border-bottom-color: var(--cyan);
  background: var(--hover);
  outline: none;
}

.page-about .chapter-nav .idx {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--cyan);
}

.page-about .chapter {
  padding: clamp(26px, 4vw, 46px) 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: 90px;
}

.page-about .chapter:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .chapter__head {
  display: grid;
  gap: 6px;
  margin-bottom: 18px;
}

.page-about .chapter__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .chapter h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.26;
  margin: 0;
  color: var(--white);
}

.page-about .chapter p {
  margin: 0 0 14px;
  max-width: 68ch;
  font-size: 16px;
  color: var(--mist);
}

.page-about .pullquote {
  margin: 22px 0 20px;
  padding: 4px 0 4px 18px;
  border-left: 2px solid var(--cyan);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(17px, 2.2vw, 21px);
  line-height: 1.55;
  color: var(--white);
}

.page-about .principles {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .principles li {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .principles .p-idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  padding-top: 3px;
}

.page-about .principles h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--white);
}

.page-about .principles p {
  margin: 0;
  font-size: 15px;
}

.page-about .timeline {
  position: relative;
  margin: 26px 0 0;
  padding-left: 26px;
  display: grid;
  gap: 10px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(to bottom, var(--cyan), rgba(53, 242, 208, 0.12));
}

.page-about .tl-item {
  position: relative;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -23px;
  top: 17px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--abyss);
  border: 1px solid var(--cyan);
  transition: background-color 0.18s ease, box-shadow 0.18s ease;
}

.page-about .tl-item[open]::before {
  background: var(--cyan);
  box-shadow: 0 0 12px rgba(53, 242, 208, 0.55);
}

.page-about .tl-item summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 12px;
  padding: 10px 13px;
  list-style: none;
  cursor: pointer;
  background: var(--panel);
  border: 1px solid transparent;
  transition: background-color 0.18s ease, border-color 0.18s ease;
}

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

.page-about .tl-item summary:hover,
.page-about .tl-item summary:focus-visible {
  background: var(--hover);
  border-color: var(--line);
  outline: none;
}

.page-about .tl-item summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .tl-item[open] summary::after {
  content: "\2212";
}

.page-about .tl-ver {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--signal);
}

.page-about .tl-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--white);
}

.page-about .tl-body {
  padding: 12px 13px 14px;
  margin: 0;
  font-size: 15px;
  color: var(--mist);
  border-left: 1px solid var(--line-soft);
  background: rgba(15, 42, 66, 0.45);
}

.page-about .about-figure {
  margin: 28px 0 0;
  border: 1px solid var(--line-soft);
  background: var(--panel);
  box-shadow: var(--shadow-panel);
}

.page-about .about-figure img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .roles {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 24px;
}

.page-about .role {
  padding-top: 14px;
  border-top: 2px solid var(--cyan);
}

.page-about .role:nth-child(2) {
  border-top-color: var(--signal);
}

.page-about .role:nth-child(3) {
  border-top-color: var(--track);
}

.page-about .role h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 600;
  color: var(--white);
}

.page-about .role p {
  margin: 0;
  font-size: 14.5px;
}

.page-about .eco-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 24px;
}

.page-about .eco-item {
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.page-about .eco-idx {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .eco-item h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 600;
  color: var(--white);
}

.page-about .eco-item p {
  margin: 0;
  font-size: 14.5px;
}

.page-about .awards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 26px;
  padding: 18px 0 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .award {
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about .award-mark {
  flex: none;
  width: 8px;
  height: 8px;
  background: var(--signal);
  transform: rotate(45deg);
}

.page-about .award p {
  margin: 0;
  font-size: 14.5px;
  color: var(--white);
  letter-spacing: 0.01em;
}

.page-about .next-track {
  margin-top: 24px;
  padding: clamp(20px, 3vw, 32px);
  border: 1px solid var(--line);
  background:
    linear-gradient(150deg, var(--night) 20%, rgba(53, 242, 208, 0.09) 100%);
  box-shadow: var(--shadow-lift);
}

.page-about .next-track__lead {
  margin: 0;
  max-width: 40ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(17px, 2.2vw, 21px);
  line-height: 1.5;
  color: var(--white);
}

.page-about .next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

@media (min-width: 720px) {
  .page-about .hero-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .roles,
  .page-about .eco-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .awards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px 24px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 1fr);
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: 208px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .chapter-nav {
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .chapter-nav ol {
    gap: 2px;
    overflow: visible;
  }

  .page-about .chapter-nav a {
    border-bottom: 0;
    border-left: 1px solid var(--line-soft);
    white-space: normal;
    padding: 8px 10px;
  }

  .page-about .chapter-nav a:hover,
  .page-about .chapter-nav a:focus-visible {
    border-left-color: var(--cyan);
    border-bottom-color: transparent;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
    animation: none !important;
  }
}