.page-about {
  --about-rail: 112px;
  --about-ink-soft: rgba(28, 20, 16, .78);
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(24px, 5vw, 60px) 0 clamp(28px, 4vw, 52px);
  border-bottom: 1px solid var(--grass-line);
  overflow: hidden;
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(20, 67, 58, .38) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(20, 67, 58, .38) 1px, transparent 1px);
  background-size: 120px 120px;
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, transparent 88%);
  mask-image: linear-gradient(to bottom, #000 0%, transparent 88%);
}
.page-about .about-hero > .wrap {
  position: relative;
  z-index: 1;
}
.page-about .about-hero__eyebrow {
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan);
}
.page-about .about-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(29px, 6vw, 56px);
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--paper);
  max-width: 17ch;
}
.page-about .about-hero__lede {
  margin: clamp(14px, 2vw, 22px) 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-soft);
}
.page-about .about-hero__stats {
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--grass-line);
  border: 1px solid var(--grass-line);
  border-radius: var(--radius);
  overflow: hidden;
}
@media (min-width: 660px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(3, 1fr);
  }
}
.page-about .about-stat {
  background: var(--night-2);
  padding: 15px 18px 18px;
}
.page-about .about-stat dt {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
  line-height: 1.5;
}
.page-about .about-stat dd {
  margin: 10px 0 0;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--flare);
}
.page-about .about-stat__unit {
  margin-left: 6px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 400;
  color: var(--mist);
  letter-spacing: 0;
}

/* ---------- Chapter shell ---------- */
.page-about .about-chapter {
  padding: clamp(38px, 7vw, 84px) 0;
  border-bottom: 1px solid var(--grass-line);
  scroll-margin-top: calc(var(--header-offset) + 16px);
}
.page-about .about-chapter--dark {
  background: var(--night-2);
}
.page-about .about-chapter--deep {
  background:
    radial-gradient(120% 90% at 12% 0%, rgba(20, 67, 58, .55) 0%, transparent 62%),
    var(--night);
}
.page-about .about-chapter--paper {
  background: var(--paper);
  color: var(--ink);
  border-bottom-color: rgba(28, 20, 16, .14);
}
.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}
@media (min-width: 860px) {
  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(28px, 5vw, 64px);
  }
}

/* ---------- Rail ---------- */
.page-about .about-rail {
  display: flex;
  flex-direction: row;
  align-items: baseline;
  gap: 12px;
}
@media (min-width: 860px) {
  .page-about .about-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    position: sticky;
    top: calc(var(--header-offset) + 24px);
    align-self: start;
  }
}
.page-about .about-rail__no {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--flare);
  text-decoration: none;
  padding-bottom: 3px;
  border-bottom: 2px solid transparent;
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.page-about .about-rail__no:hover,
.page-about .about-rail__no:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}
.page-about .about-chapter:target .about-rail__no {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}
.page-about .about-rail__label {
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--mist);
  white-space: nowrap;
}
@media (min-width: 860px) {
  .page-about .about-rail__label {
    writing-mode: vertical-rl;
    letter-spacing: .32em;
    line-height: 1;
  }
}
.page-about .about-chapter--paper .about-rail__label {
  color: rgba(28, 20, 16, .55);
}
.page-about .about-chapter--paper .about-rail__no {
  color: var(--flare-ink);
}

/* ---------- Typography ---------- */
.page-about .about-h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.6vw, 34px);
  line-height: 1.16;
  letter-spacing: -.005em;
  color: var(--paper);
  max-width: 24ch;
}
.page-about .about-chapter--paper .about-h2 {
  color: var(--ink);
}
.page-about .about-p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-soft);
  max-width: 68ch;
}
.page-about .about-p:last-child {
  margin-bottom: 0;
}
.page-about .about-p--lead {
  font-size: 17px;
  color: var(--paper);
}
.page-about .about-p--tail {
  margin-top: 20px;
}
.page-about .about-chapter--paper .about-p {
  color: var(--about-ink-soft);
}
.page-about .about-chapter--paper .about-p--lead {
  color: var(--ink);
}
.page-about .about-p a,
.page-about .about-note a,
.page-about .about-roles__text a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
.page-about .about-chapter--paper .about-p a,
.page-about .about-chapter--paper .about-note a {
  color: var(--flare-ink);
}

/* ---------- Note ---------- */
.page-about .about-note {
  margin-top: 22px;
  padding: 14px 16px;
  border-left: 2px solid var(--cyan);
  background: rgba(53, 230, 208, .07);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.page-about .about-note p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--text-soft);
}
.page-about .about-chapter--paper .about-note {
  border-left-color: var(--flare-ink);
  background: rgba(11, 36, 32, .06);
}
.page-about .about-chapter--paper .about-note p {
  color: var(--about-ink-soft);
}

/* ---------- Four lines ---------- */
.page-about .about-lines {
  margin-top: 22px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
@media (min-width: 800px) {
  .page-about .about-lines {
    grid-template-columns: repeat(12, 1fr);
    gap: 14px;
  }
  .page-about .about-line:nth-child(1) { grid-column: span 7; }
  .page-about .about-line:nth-child(2) { grid-column: span 5; }
  .page-about .about-line:nth-child(3) { grid-column: span 5; }
  .page-about .about-line:nth-child(4) { grid-column: span 7; }
}
.page-about .about-line {
  padding: 18px 18px 20px;
  border-radius: var(--radius);
  background: var(--night);
  border: 1px solid rgba(28, 20, 16, .12);
  transition: transform var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.page-about .about-line:hover {
  transform: translateY(-2px);
  border-color: var(--grass);
}
.page-about .about-line__no {
  margin: 0;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
}
.page-about .about-line:nth-child(2) .about-line__no { color: var(--amber); }
.page-about .about-line:nth-child(3) .about-line__no { color: var(--flare); }
.page-about .about-line:nth-child(4) .about-line__no { color: var(--mist); }
.page-about .about-line__title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.25;
  color: var(--paper);
}
.page-about .about-line__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-soft);
}
.page-about .about-lines__media {
  margin: 22px 0 0;
}

/* ---------- Path diagram ---------- */
.page-about .about-path {
  margin: 22px 0 20px;
  padding: 10px;
  border: 1px solid var(--grass-line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(11, 36, 32, .92), rgba(6, 26, 22, .92));
  overflow-x: auto;
}
.page-about .about-path__svg {
  display: block;
  width: 100%;
  min-width: 520px;
  height: auto;
}
.page-about .about-path__node rect {
  fill: rgba(243, 237, 225, .05);
  stroke: var(--grass);
  stroke-width: 1;
  transition: fill var(--dur-fast) var(--ease), stroke var(--dur-fast) var(--ease);
}
.page-about .about-path__node:hover rect,
.page-about .about-path__node:focus-within rect {
  fill: rgba(53, 230, 208, .1);
  stroke: var(--cyan);
}
.page-about .about-path__no {
  font-family: var(--font-data);
  font-size: 13px;
  letter-spacing: .1em;
  fill: var(--flare);
}
.page-about .about-path__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 25px;
  fill: var(--paper);
}
.page-about .about-path__hint {
  font-family: var(--font-body);
  font-size: 13px;
  fill: var(--mist);
  opacity: 0;
  transition: opacity var(--dur-fast) var(--ease);
}
.page-about .about-path__node:hover .about-path__hint,
.page-about .about-path__node:focus-within .about-path__hint {
  opacity: 1;
}
.page-about .about-path__link {
  stroke: var(--grass);
  stroke-width: 1.5;
}
.page-about .about-path__arrow {
  fill: var(--grass);
}

/* ---------- Flow steps ---------- */
.page-about .about-flow {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
@media (min-width: 760px) {
  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }
}
.page-about .about-flow__item {
  padding: 18px 18px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--grass-line);
  background: rgba(6, 26, 22, .6);
}
.page-about .about-flow__no {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--night);
  background: var(--cyan);
  padding: 3px 8px;
  border-radius: 999px;
}
.page-about .about-flow__item:nth-child(2) .about-flow__no { background: var(--amber); }
.page-about .about-flow__item:nth-child(3) .about-flow__no { background: var(--paper-2); }
.page-about .about-flow__item:nth-child(4) .about-flow__no { background: var(--flare); color: var(--paper); }
.page-about .about-flow__title {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.25;
  color: var(--paper);
}
.page-about .about-flow__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
}
.page-about .about-flow__media {
  margin: 22px 0 0;
}

/* ---------- Timestamp table ---------- */
.page-about .about-stamp {
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1px;
  background: rgba(28, 20, 16, .16);
  border: 1px solid rgba(28, 20, 16, .16);
  border-radius: var(--radius);
  overflow: hidden;
}
.page-about .about-stamp > div {
  background: var(--paper);
  padding: 15px 16px 17px;
}
.page-about .about-stamp dt {
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(28, 20, 16, .6);
  line-height: 1.5;
}
.page-about .about-stamp dd {
  margin: 9px 0 0;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: .01em;
  color: var(--flare-ink);
}

/* ---------- Roles tabs ---------- */
.page-about .about-roles {
  margin-top: 24px;
}
.page-about .about-roles__bar {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}
.page-about .about-roles__bar .tab {
  flex: 0 0 auto;
  padding: 9px 16px;
  border-radius: 999px;
  border: 1px solid var(--grass);
  background: transparent;
  color: var(--text-soft);
  font-family: var(--font-body);
  font-size: 13.5px;
  line-height: 1.4;
  cursor: pointer;
  white-space: nowrap;
  transition: background var(--dur-fast) var(--ease),
              color var(--dur-fast) var(--ease),
              border-color var(--dur-fast) var(--ease);
}
.page-about .about-roles__bar .tab:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}
.page-about .about-roles__bar .tab[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--night);
  font-weight: 700;
}
.page-about .about-roles__bar .tab:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}
.page-about .about-roles .tabpanel {
  margin-top: 18px;
  padding: 20px 18px 22px;
  border-radius: var(--radius);
  border: 1px solid var(--grass-line);
  background: rgba(243, 237, 225, .04);
}
.page-about .about-roles .tabpanel + .tabpanel {
  margin-top: 12px;
}
.page-about .about-roles .tabpanel[hidden] {
  display: none;
}
.page-about .about-roles .tabpanel:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}
.page-about .about-roles__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.25;
  color: var(--paper);
}
.page-about .about-roles__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 62ch;
}

/* ---------- Evolution ruler ---------- */
.page-about .about-timeline-wrap {
  position: relative;
  margin-top: 24px;
  padding: 26px 18px 26px 22px;
  border-radius: var(--radius);
  border: 1px solid var(--grass-line);
  overflow: hidden;
  isolation: isolate;
}
.page-about .about-timeline-wrap > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
  opacity: .3;
}
.page-about .about-timeline-wrap::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(6, 26, 22, .8), rgba(6, 26, 22, .95));
}
.page-about .about-ruler {
  position: relative;
  z-index: 2;
  margin: 0;
  padding: 0 0 0 30px;
  list-style: none;
}
.page-about .about-ruler::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: repeating-linear-gradient(to bottom, var(--grass) 0 8px, transparent 8px 18px);
}
.page-about .about-ruler__item {
  position: relative;
  padding-bottom: 26px;
}
.page-about .about-ruler__item:last-child {
  padding-bottom: 0;
}
.page-about .about-ruler__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 7px;
  width: 15px;
  height: 2px;
  background: var(--cyan);
}
.page-about .about-ruler__stage {
  margin: 0;
  font-family: var(--font-data);
  font-size: 11.5px;
  letter-spacing: .16em;
  color: var(--amber);
}
.page-about .about-ruler__title {
  margin: 8px 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.28;
  color: var(--paper);
}
.page-about .about-ruler__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 60ch;
}

/* ---------- Media frames inside page ---------- */
.page-about .media-frame {
  border-radius: var(--radius);
  overflow: hidden;
}
.page-about .media-frame__caption {
  font-size: 12.5px;
  letter-spacing: .04em;
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-line,
  .page-about .about-rail__no,
  .page-about .about-roles__bar .tab,
  .page-about .about-path__node rect,
  .page-about .about-path__hint {
    transition: none;
  }
  .page-about .about-line:hover {
    transform: none;
  }
}

/* ---------- Wider screens ---------- */
@media (min-width: 1100px) {
  .page-about {
    --about-rail: 128px;
  }
  .page-about .about-timeline-wrap {
    padding: 34px 32px 34px 34px;
  }
  .page-about .about-ruler {
    padding-left: 38px;
  }
  .page-about .about-ruler__item::before {
    left: -38px;
    width: 20px;
  }
}
<<<END>>>