.page-about {
  --rail: 236px;
  --about-pad: clamp(36px, 6vw, 76px);
  padding-bottom: clamp(56px, 9vw, 112px);
  background:
    radial-gradient(900px 520px at 92% -8%, rgba(47, 243, 214, .10), transparent 70%),
    radial-gradient(760px 460px at 4% 34%, rgba(27, 143, 126, .13), transparent 72%);
}

.page-about .breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
}

.page-about .breadcrumbs li:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--line);
}

/* ---------- hero ---------- */
.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(30px, 5vw, 60px);
  padding-block: clamp(26px, 4vw, 54px) clamp(34px, 5vw, 68px);
  align-items: end;
}

.page-about .eyebrow {
  margin: 0 0 14px;
  letter-spacing: .18em;
}

.page-about .about-hero__copy h1 {
  margin: 0 0 20px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(2.1rem, 6.2vw, 4rem);
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--text);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 46ch;
  color: var(--muted);
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.85;
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 28px;
  margin: 26px 0 0;
  padding: 18px 0 0;
  list-style: none;
  border-top: 1px dashed var(--line);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-hero__fnum {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-hero__flabel {
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
}

.page-about .hero-board {
  position: relative;
  padding: 20px 18px 16px;
  background: linear-gradient(160deg, var(--panel), rgba(20, 56, 45, .55));
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .hero-board::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(35, 69, 58, .5) 1px, transparent 1px),
    linear-gradient(90deg, rgba(35, 69, 58, .5) 1px, transparent 1px);
  background-size: 26px 26px;
  opacity: .35;
  pointer-events: none;
}

.page-about .hero-board__head {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 12px;
  margin-bottom: 6px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-cond);
  font-size: 13px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .hero-board__code {
  font-family: var(--font-mono);
  color: var(--cyan);
  letter-spacing: .1em;
}

.page-about .hero-board__list {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .hero-board__item {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px dashed rgba(35, 69, 58, .9);
}

.page-about .hero-board__item:last-child {
  border-bottom: 0;
}

.page-about .hero-board__n {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--teal);
  padding-top: 3px;
}

.page-about .hero-board__item strong {
  display: block;
  font-family: var(--font-cond);
  font-size: 1.05rem;
  letter-spacing: .04em;
  color: var(--text);
}

.page-about .hero-board__item p {
  margin: 4px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- full bleed figure ---------- */
.page-about .about-bleed {
  position: relative;
  margin: 0;
  height: clamp(200px, 38vw, 430px);
  overflow: hidden;
  background: var(--panel);
}

.page-about .about-bleed img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: saturate(.8) brightness(.7);
}

.page-about .about-bleed::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(8, 19, 15, .7), rgba(8, 19, 15, .12) 46%, rgba(8, 19, 15, .94));
  pointer-events: none;
}

.page-about .about-bleed figcaption {
  position: absolute;
  left: var(--gutter);
  right: var(--gutter);
  bottom: 16px;
  z-index: 1;
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--muted);
}

/* ---------- shell + index ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 56px);
  margin-top: clamp(30px, 5vw, 64px);
}

.page-about .about-index__title {
  margin: 0 0 10px;
  font-family: var(--font-cond);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-index ol {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index ol::-webkit-scrollbar {
  display: none;
}

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

.page-about .about-index__link {
  display: inline-block;
  padding: 7px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s var(--ease), border-color .18s var(--ease), background .18s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--cyan);
  border-color: var(--teal);
}

.page-about .about-index__link.is-active {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- section heads ---------- */
.page-about .about-sec {
  padding-block: var(--about-pad);
  border-top: 1px dashed var(--line);
}

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

.page-about .about-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-bottom: clamp(24px, 3.4vw, 42px);
}

.page-about .about-head__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
  padding-top: 6px;
  border-top: 2px solid var(--cyan);
  width: max-content;
}

.page-about .about-head h2 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.45rem, 3.3vw, 2.15rem);
  line-height: 1.28;
  letter-spacing: -.005em;
  color: var(--text);
}

.page-about .about-head p {
  margin: 0;
  max-width: 62ch;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}

/* ---------- chain ---------- */
.page-about .chain {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .chain::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 0;
  border-left: 2px dashed var(--line);
}

.page-about .chain__item {
  position: relative;
  padding: 0 0 28px;
}

.page-about .chain__item:last-child {
  padding-bottom: 0;
}

.page-about .chain__dot {
  position: absolute;
  left: -26px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--teal);
}

.page-about .chain__item:first-child .chain__dot {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 5px rgba(47, 243, 214, .14);
}

.page-about .chain__stage {
  margin: 0 0 6px;
  font-family: var(--font-cond);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .chain__item h3 {
  margin: 0 0 8px;
  font-size: 1.06rem;
  font-weight: 600;
  color: var(--text);
}

.page-about .chain__item p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}

/* ---------- collage band ---------- */
.page-about .stack-band {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-inline: calc(-1 * var(--gutter));
  padding: 22px var(--gutter);
  background: linear-gradient(120deg, rgba(15, 42, 34, .92), rgba(9, 24, 19, .55));
  border-block: 1px solid var(--line);
}

.page-about .stack-panel {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 18px;
  background: var(--panel);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .stack-panel h3 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--text);
}

.page-about .stack-panel p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .stack-panel__note {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  font-size: 12.5px;
  letter-spacing: .03em;
  color: var(--teal);
}

.page-about .stack-panel .chip {
  align-self: flex-start;
}

.page-about .stack-panel__media {
  margin: -20px -18px 4px;
  overflow: hidden;
  background: var(--ink);
}

.page-about .stack-panel__media img {
  display: block;
  width: 100%;
  height: 150px;
  object-fit: cover;
  filter: saturate(.75) brightness(.68);
}

.page-about .stack-panel--c {
  background: linear-gradient(155deg, var(--raise), rgba(15, 42, 34, .9));
}

/* ---------- era timeline ---------- */
.page-about .era {
  position: relative;
  padding-left: 12px;
}

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

.page-about .era__item {
  position: relative;
  padding-left: 26px;
  margin-bottom: 12px;
}

.page-about .era__item::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 0;
  bottom: 0;
  border-left: 1px solid var(--line);
}

.page-about .era__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--teal);
}

.page-about .era__details {
  background: rgba(15, 42, 34, .5);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .era__details[open] {
  background: var(--panel);
  border-color: var(--teal);
}

.page-about .era__details summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .era__ver {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--amber);
  letter-spacing: .06em;
}

.page-about .era__label {
  font-family: var(--font-cond);
  font-size: 1.02rem;
  letter-spacing: .04em;
  color: var(--text);
}

.page-about .era__plus {
  position: relative;
  width: 14px;
  height: 14px;
  flex: 0 0 auto;
}

.page-about .era__plus::before,
.page-about .era__plus::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}

.page-about .era__plus::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.page-about .era__plus::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
}

.page-about .era__details[open] .era__plus::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .era__panel {
  padding: 0 16px 16px;
}

.page-about .era__panel p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
  border-top: 1px dashed var(--line);
  padding-top: 12px;
}

/* ---------- metric band ---------- */
.page-about .metric-band {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.page-about .metric-band__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.6) brightness(.32);
}

.page-about .metric-band__grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(35, 69, 58, .7);
}

.page-about .metric {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 16px;
  background: rgba(9, 24, 19, .82);
}

.page-about .metric__v {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 4.6vw, 2.3rem);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -.02em;
}

.page-about .metric__u {
  font-size: .5em;
  margin-left: 4px;
  color: var(--amber);
}

.page-about .metric__k {
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .03em;
  color: var(--muted);
}

/* ---------- crew ---------- */
.page-about .crew {
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
}

.page-about .crew__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

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

.page-about .crew__role {
  font-family: var(--font-cond);
  font-size: 1.05rem;
  letter-spacing: .08em;
  color: var(--cyan);
}

.page-about .crew__text p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .sla {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .sla__cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: var(--raise);
}

.page-about .sla__v {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  color: var(--amber);
}

.page-about .sla__k {
  font-size: 12.5px;
  letter-spacing: .03em;
  color: var(--muted);
}

/* ---------- identity ---------- */
.page-about .identity {
  padding: 6px 18px 18px;
  background: linear-gradient(150deg, var(--panel), rgba(20, 56, 45, .6));
}

.page-about .identity__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .identity__k {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--muted);
}

.page-about .identity__v {
  font-family: var(--font-mono);
  font-size: .95rem;
  line-height: 1.6;
  color: var(--text);
  word-break: break-word;
}

.page-about .identity__v a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 243, 214, .35);
}

.page-about .identity__v a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .identity__note {
  margin: 16px 0 0;
  font-size: 12.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- jump links ---------- */
.page-about .about-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 26px 0 0;
}

/* ---------- responsive ---------- */
@media (min-width: 680px) {
  .page-about .about-head {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 18px;
  }

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

  .page-about .crew__row {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 20px;
    align-items: start;
  }

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

  .page-about .identity__row {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: baseline;
    gap: 14px;
  }

  .page-about .stack-panel__media img {
    height: 200px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
  }

  .page-about .about-shell {
    grid-template-columns: var(--rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-pad) + 84px);
  }

  .page-about .about-index ol {
    display: block;
    overflow: visible;
    padding: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index li {
    display: block;
  }

  .page-about .about-index__link {
    display: block;
    padding: 9px 0 9px 14px;
    margin-left: -1px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    background: none;
    white-space: normal;
    font-size: 13.5px;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    color: var(--text);
    border-left-color: var(--teal);
    background: none;
  }

  .page-about .about-index__link.is-active {
    color: var(--cyan);
    background: none;
    border-left-color: var(--cyan);
  }

  .page-about .stack-band {
    grid-template-columns: 0.92fr 0.82fr 1.06fr;
    align-items: start;
    gap: 20px;
    padding-block: 30px;
  }

  .page-about .stack-panel--a {
    min-height: 420px;
  }

  .page-about .stack-panel--b {
    min-height: 330px;
    margin-top: 58px;
  }

  .page-about .stack-panel--c {
    min-height: 380px;
    margin-top: 116px;
  }

  .page-about .stack-panel__media img {
    height: 172px;
  }

  .page-about .era__item {
    padding-left: 34px;
  }

  .page-about .era__details summary {
    padding: 16px 20px;
  }

  .page-about .era__panel {
    padding: 0 20px 18px;
  }

  .page-about .metric__v {
    font-size: 2.1rem;
  }
}

@media (min-width: 1200px) {
  .page-about .stack-panel--a {
    min-height: 460px;
  }

  .page-about .stack-panel--c {
    margin-top: 136px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .era__plus::before,
  .page-about .era__plus::after {
    transition: none;
  }
}
<<<END>>>