.page-about {
  --about-pad: clamp(1.25rem, 3vw, 2.25rem);
  --about-gap: clamp(1.5rem, 3.4vw, 2.5rem);
  position: relative;
  background:
    radial-gradient(1100px 520px at 84% -6%, rgba(34, 211, 238, 0.1), transparent 62%),
    radial-gradient(880px 460px at 4% 4%, rgba(255, 106, 0, 0.1), transparent 64%),
    var(--space-900);
  color: var(--body-text);
  overflow-x: clip;
}

.page-about a {
  color: var(--cyan);
}

.page-about a:hover,
.page-about a:focus-visible {
  color: var(--orange);
}

.page-about .about-crumb {
  padding-top: clamp(1rem, 3vw, 1.75rem);
}

.page-about .breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--cyan);
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  position: relative;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(140, 163, 184, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(140, 163, 184, 0.07) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 88%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 88%);
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-hero__lead h1 {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(2.1rem, 6.4vw, 4.4rem);
  line-height: 1.02;
  letter-spacing: 0.01em;
  color: var(--paper);
  margin: 0.5rem 0 1rem;
  text-wrap: balance;
}

.page-about .about-hero__text {
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--body-text);
  margin: 0 0 0.85rem;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.5rem;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  background: var(--midnight);
  padding: 0.95rem 1rem 1.05rem;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(1.35rem, 3.4vw, 1.85rem);
  line-height: 1.1;
  color: var(--orange);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--mist);
}

/* ---------- Layout ---------- */
.page-about .about-body {
  padding-top: clamp(1.5rem, 3vw, 2.5rem);
}

.page-about .about-layout {
  display: grid;
  gap: var(--about-gap);
}

/* ---------- Rail ---------- */
.page-about .about-rail {
  border: 1px solid var(--line);
  background: rgba(14, 42, 74, 0.62);
  padding: 1rem 1rem 1.15rem;
}

.page-about .about-rail__title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--pulse);
  margin: 0 0 0.75rem;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__list li {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
  padding: 0.4rem 0.7rem;
  border: 1px solid var(--line);
  color: var(--body-text);
  font-size: 0.82rem;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--orange);
  color: var(--paper);
}

.page-about .about-rail__num {
  font-size: 0.72rem;
  color: var(--orange);
}

.page-about .about-rail__timeline {
  display: flex;
  gap: 0.9rem;
  margin-top: 1rem;
  padding-top: 0.8rem;
  border-top: 1px dashed var(--line-soft);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- Chapters ---------- */
.page-about .about-chapters {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-chapter {
  position: relative;
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
  background: linear-gradient(180deg, rgba(14, 42, 74, 0.86), rgba(10, 36, 64, 0.55));
  padding: var(--about-pad);
}

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 0.85rem;
}

.page-about .about-chapter__idx {
  color: var(--pulse);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
}

.page-about .about-chapter h2 {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(1.5rem, 3.6vw, 2.35rem);
  line-height: 1.12;
  letter-spacing: 0.01em;
  color: var(--paper);
  margin: 0;
}

.page-about .about-chapter h3 {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(1.05rem, 2.2vw, 1.35rem);
  letter-spacing: 0.02em;
  color: var(--cyan);
  margin: 0 0 0.5rem;
}

.page-about .about-chapter__lead {
  max-width: 68ch;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--paper);
  border-left: 2px solid rgba(34, 211, 238, 0.5);
  padding-left: 0.85rem;
  margin: 0 0 1.1rem;
}

.page-about .about-chapter .prose p {
  max-width: 72ch;
  font-size: 0.97rem;
  line-height: 1.8;
  color: var(--body-text);
  margin: 0 0 0.85rem;
}

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

/* ---------- Figures ---------- */
.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--space-800);
  padding: 0.6rem 0.6rem 0.75rem;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--line-soft);
  filter: saturate(1.05) contrast(1.02);
}

.page-about .about-figure__cap {
  margin-top: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- Flow ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 0 0 1.5rem;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-flow__item {
  background: var(--space-800);
  padding: 0.9rem 1rem;
  display: grid;
  gap: 0.3rem;
}

.page-about .about-flow__phase {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .about-flow__desc {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--body-text);
}

/* ---------- Details ---------- */
.page-about .about-details {
  margin-top: 1.5rem;
  border: 1px dashed var(--line-strong);
  background: rgba(11, 107, 117, 0.12);
  padding: 0.85rem 1rem;
}

.page-about .about-details__summary {
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--pulse);
  list-style: none;
}

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

.page-about .about-details__summary::before {
  content: "+ ";
  color: var(--orange);
}

.page-about .about-details[open] .about-details__summary::before {
  content: "– ";
}

.page-about .about-details .prose {
  margin-top: 0.75rem;
}

/* ---------- Stages / tabs ---------- */
.page-about .about-stages {
  margin-bottom: 1.5rem;
}

.page-about .about-stages__tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.page-about .about-stage {
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
  background: var(--midnight);
  padding: 1rem 1.1rem 1.15rem;
}

.page-about .about-stage__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.1em;
  color: var(--orange);
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 0.2rem;
  margin: 0 0 0.6rem;
}

.page-about .about-stage h3 {
  margin-top: 0;
}

.page-about .about-stage p {
  margin: 0;
  max-width: 68ch;
  font-size: 0.95rem;
  line-height: 1.78;
  color: var(--body-text);
}

/* ---------- Ecosystem ---------- */
.page-about .about-eco {
  margin-top: 0.5rem;
}

.page-about .about-eco__col {
  border-top: 2px solid var(--chili);
  background: rgba(226, 58, 46, 0.07);
  padding: 1rem 1.1rem 1.15rem;
}

.page-about .about-eco__col p {
  margin: 0 0 0.7rem;
  max-width: 46ch;
  font-size: 0.93rem;
  line-height: 1.75;
  color: var(--body-text);
}

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

.page-about .about-honor li {
  display: flex;
  gap: 0.6rem;
  align-items: baseline;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--line-soft);
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--body-text);
}

.page-about .about-honor li:last-child {
  border-bottom: none;
}

.page-about .about-honor .num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.82rem;
  color: var(--pulse);
  flex: 0 0 auto;
}

/* ---------- Notes ---------- */
.page-about .about-notes {
  display: grid;
  gap: 0.85rem;
  align-content: start;
}

.page-about .about-note {
  border: 1px solid var(--line);
  background: var(--space-800);
  padding: 0.9rem 1rem 1rem;
}

.page-about .about-note--paper {
  background: var(--paper);
  color: var(--ink);
  border-color: var(--ink);
}

.page-about .about-note__title {
  margin: 0 0 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-note--paper .about-note__title {
  color: var(--chili);
}

.page-about .about-note__stat {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 1.5rem;
  line-height: 1.1;
  color: var(--orange);
}

.page-about .about-note--paper .about-note__stat {
  color: var(--ink);
}

.page-about .about-note__label {
  margin: 0.15rem 0 0.7rem;
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--mist);
}

.page-about .about-note--paper .about-note__label {
  color: #4A3B2E;
}

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

.page-about .about-note__list li {
  padding: 0.42rem 0;
  border-bottom: 1px solid var(--line-soft);
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--body-text);
}

.page-about .about-note__list li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .about-note__list--links li {
  border-bottom-style: dashed;
}

.page-about .about-note__list--links a {
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 211, 238, 0.4);
}

/* ---------- Close ---------- */
.page-about .about-close {
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(11, 107, 117, 0.16), transparent 70%);
}

.page-about .about-close__grid {
  display: grid;
  gap: 1.25rem;
}

.page-about .about-close h2 {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  line-height: 1.12;
  color: var(--paper);
  margin: 0 0 0.7rem;
}

.page-about .about-close__text {
  max-width: 64ch;
  margin: 0;
  font-size: 0.97rem;
  line-height: 1.78;
  color: var(--body-text);
}

.page-about .about-close__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  align-items: flex-start;
}

/* ---------- Responsive ---------- */
@media (min-width: 620px) {
  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-figure img {
    aspect-ratio: 16 / 10;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
    align-items: end;
  }

  .page-about .about-close__grid {
    grid-template-columns: minmax(0, 1.5fr) auto;
    align-items: center;
  }

  .page-about .about-close__actions {
    justify-content: flex-end;
  }

  .page-about .about-figure img {
    aspect-ratio: 3 / 2;
  }
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: 204px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 7rem;
  }

  .page-about .about-rail__list {
    display: block;
    overflow: visible;
    padding-left: 0.85rem;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__list li + li {
    margin-top: 0.35rem;
  }

  .page-about .about-rail__link {
    border: none;
    border-bottom: 1px solid var(--line-soft);
    padding: 0.42rem 0;
    white-space: normal;
    font-size: 0.85rem;
    color: var(--mist);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    color: var(--paper);
    border-bottom-color: var(--orange);
  }
}

@media (min-width: 1240px) {
  .page-about .about-layout {
    grid-template-columns: 204px minmax(0, 1fr) 236px;
  }

  .page-about .about-notes {
    position: sticky;
    top: 7rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about a {
    transition: none;
  }
}