.page-about {
  --about-rail: 200px;
  --about-flow-gap: clamp(3.25rem, 7vw, 5.5rem);
  display: block;
  padding-bottom: clamp(3rem, 8vw, 6rem);
}

.page-about .about-shell {
  width: min(var(--shell-max), 100% - var(--gutter) * 2);
  margin-inline: auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
}

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: var(--about-flow-gap);
  min-width: 0;
}

/* ---------- side rail ---------- */
.page-about .about-rail {
  display: none;
}

.page-about .rail-head {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted-dim);
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.1rem;
}

.page-about .rail-list a {
  display: block;
  padding: 0.5rem 0;
  font-size: 0.875rem;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .rail-list a:hover,
.page-about .rail-list a:focus-visible {
  color: var(--gold-soft);
  border-bottom-color: var(--gold);
}

/* ---------- shared section rhythm ---------- */
.page-about .about-hero,
.page-about .chapter,
.page-about .about-cta {
  scroll-margin-top: 7.5rem;
}

.page-about .chapter {
  position: relative;
}

.page-about .chapter-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.35rem 1rem;
  align-items: baseline;
  border-top: 1px solid var(--line);
  padding-top: 1.15rem;
  margin-bottom: clamp(1.3rem, 3vw, 2rem);
}

.page-about .chapter-num {
  padding-top: 0.4rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .chapter-title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(1.5rem, 1.05rem + 1.9vw, 2.4rem);
  line-height: 1.22;
  letter-spacing: -0.005em;
  color: var(--text);
  text-wrap: balance;
}

.page-about .chapter-mark {
  display: none;
  position: absolute;
  top: 1.15rem;
  right: 0;
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.3em;
  color: var(--muted-dim);
  pointer-events: none;
}

.page-about .chapter-lede {
  margin: 0 0 clamp(1.4rem, 3vw, 2rem);
  max-width: 62ch;
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .chapter p {
  color: var(--muted);
  line-height: 1.8;
}

.page-about .chapter p a,
.page-about .about-cta p a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 214, 224, 0.4);
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .chapter p a:hover,
.page-about .about-cta p a:hover,
.page-about .chapter p a:focus-visible,
.page-about .about-cta p a:focus-visible {
  color: var(--gold-soft);
  border-bottom-color: var(--gold);
}

/* ---------- hero ---------- */
.page-about .about-hero {
  display: grid;
  gap: 1.5rem;
}

.page-about .breadcrumb {
  margin-bottom: 0.25rem;
}

.page-about .hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.75rem, 4vw, 3rem);
  align-items: center;
}

.page-about .hero-copy h1 {
  margin: 0.6rem 0 1rem;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(2.05rem, 1.3rem + 3.6vw, 3.7rem);
  line-height: 1.14;
  letter-spacing: -0.012em;
  color: var(--text);
  text-wrap: balance;
}

.page-about .hero-copy .lede {
  margin: 0;
  max-width: 60ch;
  color: var(--muted);
}

.page-about .hero-note {
  margin: 1.15rem 0 0;
  display: block;
  padding-left: 0.85rem;
  border-left: 2px solid var(--gold);
  color: var(--muted-dim);
  letter-spacing: 0.06em;
}

.page-about .hero-visual {
  position: relative;
  margin: 0;
  isolation: isolate;
}

.page-about .hero-visual::before {
  content: "";
  position: absolute;
  inset: auto 4% -5% 10%;
  height: 42%;
  background: linear-gradient(120deg, rgba(53, 214, 224, 0.34), rgba(227, 178, 90, 0.16) 62%, transparent);
  clip-path: polygon(0 32%, 100% 0, 92% 100%, 6% 88%);
  z-index: -1;
  pointer-events: none;
}

.page-about .hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  border-radius: var(--radius-lg);
  clip-path: polygon(0 0, 100% 5%, 100% 100%, 0 94%);
  filter: saturate(0.92);
}

/* ---------- task list (chapter 01) ---------- */
.page-about .task-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .task-item {
  display: grid;
  gap: 0.45rem;
  padding: clamp(1.1rem, 2.6vw, 1.8rem);
  background: linear-gradient(160deg, var(--abyss), var(--abyss-deep));
  transition: background 0.3s var(--ease);
}

.page-about .task-item:hover {
  background: linear-gradient(160deg, #151E31, var(--abyss-deep));
}

.page-about .task-key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .task-item h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.1rem;
  line-height: 1.45;
  color: var(--text);
}

.page-about .task-item p {
  margin: 0;
  font-size: 0.95rem;
}

/* ---------- timeline (chapter 02) ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr);
  gap: 0.35rem 1.1rem;
  padding: 1.35rem 0 1.35rem 1.5rem;
  border-bottom: 1px solid var(--line);
}

.page-about .timeline-item:first-child {
  border-top: 1px solid var(--line);
}

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.95rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan-deep);
  box-shadow: 0 0 0 4px rgba(53, 214, 224, 0.1);
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .timeline-item:hover::before,
.page-about .timeline-item:focus-within::before {
  background: var(--gold);
  box-shadow: 0 0 0 6px rgba(227, 178, 90, 0.16);
}

.page-about .timeline-year {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .timeline-body h3 {
  margin: 0 0 0.45rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.08rem;
  line-height: 1.5;
  color: var(--text);
}

.page-about .timeline-body p {
  margin: 0;
  font-size: 0.95rem;
}

/* ---------- editorial (chapter 03) ---------- */
.page-about .editorial {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 3vw, 2.5rem);
  align-items: start;
}

.page-about .editorial-media {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius-md);
  clip-path: polygon(0 3%, 100% 0, 100% 97%, 0 100%);
}

.page-about .editorial-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 6;
  object-fit: cover;
}

.page-about .editorial-body p {
  margin: 0 0 1.1rem;
}

.page-about .editorial-body p:last-child {
  margin-bottom: 0;
}

.page-about .stats {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.page-about .stat {
  display: grid;
  gap: 0.35rem;
  padding: 1.15rem 0.95rem;
  background: var(--deep-space);
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 1rem + 1vw, 1.85rem);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold-soft);
}

.page-about .stat-label {
  font-size: 0.78rem;
  line-height: 1.6;
  letter-spacing: 0.03em;
  color: var(--muted-dim);
}

/* ---------- support (chapter 04) ---------- */
.page-about .support-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
}

.page-about .support-card {
  padding: 1.25rem 1.15rem;
  background: var(--glass);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .support-card:hover {
  border-color: rgba(227, 178, 90, 0.42);
  background: var(--glass-high);
}

.page-about .support-tag {
  margin: 0 0 0.7rem;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .support-card h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.05rem;
  line-height: 1.45;
  color: var(--text);
}

.page-about .support-card p {
  margin: 0;
  font-size: 0.92rem;
}

.page-about .support-note {
  margin: clamp(1.4rem, 3vw, 2rem) 0 0;
  max-width: 64ch;
  font-size: 0.95rem;
}

.page-about .wide-figure {
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
}

.page-about .wide-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 7;
  object-fit: cover;
  border-radius: var(--radius-md);
  clip-path: polygon(0 0, 100% 4%, 100% 100%, 0 96%);
}

.page-about .wide-figure figcaption {
  margin-top: 0.9rem;
  padding-left: 0.75rem;
  border-left: 2px solid var(--gold);
  font-size: 0.82rem;
  line-height: 1.7;
  letter-spacing: 0.03em;
  color: var(--muted-dim);
}

/* ---------- collab list (chapter 05) ---------- */
.page-about .collab-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .collab-item {
  display: grid;
  gap: 0.4rem;
  padding: 1.3rem 0 1.3rem 1.25rem;
  border-left: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  transition: border-left-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .collab-item:first-child {
  border-top: 1px solid var(--line);
}

.page-about .collab-item:hover {
  border-left-color: var(--cyan);
  background: linear-gradient(90deg, rgba(53, 214, 224, 0.07), transparent 62%);
}

.page-about .collab-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .collab-item p {
  margin: 0;
  font-size: 0.95rem;
}

/* ---------- reasons (chapter 06) ---------- */
.page-about .reason-list {
  margin: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .reason {
  padding: 1.35rem 1.2rem;
  background: var(--abyss);
  transition: background 0.3s var(--ease);
}

.page-about .reason:hover {
  background: #131C2E;
}

.page-about .reason dt {
  margin-bottom: 0.55rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .reason dd {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- closing cta ---------- */
.page-about .about-cta {
  position: relative;
  padding: clamp(1.75rem, 4vw, 2.75rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(160deg, rgba(16, 39, 92, 0.55), rgba(7, 11, 24, 0.9) 62%),
    var(--abyss-deep);
  overflow: hidden;
}

.page-about .about-cta::after {
  content: "";
  position: absolute;
  top: -30%;
  right: -8%;
  width: 46%;
  height: 150%;
  background: linear-gradient(160deg, rgba(53, 214, 224, 0.18), transparent 68%);
  clip-path: polygon(38% 0, 100% 0, 100% 100%, 0 84%);
  pointer-events: none;
}

.page-about .about-cta h2 {
  position: relative;
  margin: 0 0 0.85rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(1.35rem, 1.05rem + 1.2vw, 1.95rem);
  line-height: 1.3;
  color: var(--text);
}

.page-about .about-cta p {
  position: relative;
  margin: 0 0 1.5rem;
  max-width: 60ch;
  font-size: 0.97rem;
}

.page-about .cta-actions {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

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

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

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

@media (min-width: 760px) {
  .page-about .task-item {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 0.45rem 1.75rem;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
  }

  .page-about .editorial {
    grid-template-columns: minmax(0, 0.78fr) minmax(0, 1fr);
    gap: clamp(1.75rem, 3.5vw, 3rem);
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 4rem);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 7rem;
    padding-left: 1.1rem;
    border-left: 1px solid var(--line-strong);
  }

  .page-about .chapter-head {
    padding-right: 2.25rem;
  }

  .page-about .chapter-mark {
    display: block;
  }

  .page-about .timeline-item {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 0.35rem 1.75rem;
  }

  .page-about .timeline-item:nth-child(even) {
    margin-left: clamp(1rem, 4vw, 3.25rem);
  }
}

@media (min-width: 1200px) {
  .page-about .hero-copy .lede {
    font-size: 1.0625rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-list a,
  .page-about .task-item,
  .page-about .timeline-item::before,
  .page-about .support-card,
  .page-about .collab-item,
  .page-about .reason,
  .page-about .chapter p a,
  .page-about .about-cta p a {
    transition: none;
  }
}