.page-about {
  --ab-rail: clamp(46px, 6vw, 76px);
  --ab-pad: clamp(18px, 3vw, 34px);
  --ab-cut: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
  --ab-amber-line: rgba(244, 183, 64, 0.34);
}

.page-about .ab-hero {
  position: relative;
  margin: clamp(14px, 2.2vw, 26px) 0 0;
  padding: var(--ab-pad);
  padding-bottom: calc(var(--ab-pad) + 14px);
  display: grid;
  gap: clamp(20px, 3vw, 38px);
  background:
    radial-gradient(130% 100% at 0% 0%, var(--tint-cyan), transparent 58%),
    linear-gradient(180deg, var(--ink-800), var(--ink-900));
  clip-path: var(--ab-cut);
  overflow: hidden;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan-400), transparent 76%);
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 12px;
  background: repeating-linear-gradient(90deg, var(--line-strong) 0 1px, transparent 1px 14px);
  opacity: 0.55;
  pointer-events: none;
}

.page-about .ab-hero__main h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.85rem, 4.6vw, 3.3rem);
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--paper-100);
  margin: 12px 0 0;
  max-width: 20ch;
}

.page-about .ab-hero__lead {
  margin: 16px 0 0;
  max-width: 46ch;
  color: var(--slate-300);
  font-size: clamp(0.95rem, 1.4vw, 1.05rem);
  line-height: 1.8;
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .ab-hero__side {
  padding: clamp(16px, 2.2vw, 22px);
  background: linear-gradient(170deg, var(--ink-700), var(--ink-800));
  border: 1px solid var(--line);
  clip-path: var(--ab-cut);
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .ab-hero__side-label {
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--cyan-200);
  margin: 0;
}

.page-about .ab-quick {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
}

.page-about .ab-quick li {
  background: var(--ink-800);
}

.page-about .ab-quick a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 12px;
  color: var(--slate-300);
  text-decoration: none;
  font-size: 0.92rem;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .ab-quick a:hover,
.page-about .ab-quick a:focus-visible {
  color: var(--amber-300);
  background: var(--ink-700);
}

.page-about .ab-origin__grid {
  display: grid;
  gap: clamp(24px, 3.4vw, 44px);
  align-items: start;
}

.page-about .ab-origin h2,
.page-about .ab-timeline h2,
.page-about .ab-center h2,
.page-about .ab-team h2,
.page-about .ab-service h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 3vw, 2.3rem);
  line-height: 1.2;
  color: var(--paper-100);
  margin: 10px 0 0;
}

.page-about .ab-origin__text p {
  margin: 14px 0 0;
  color: var(--slate-300);
  line-height: 1.8;
  max-width: 52ch;
}

.page-about .ab-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-facts li {
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  padding: 16px 14px;
  background: var(--ink-800);
}

.page-about .ab-facts__num {
  font-size: clamp(1.15rem, 2.4vw, 1.6rem);
  font-weight: 700;
  color: var(--amber-500);
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.page-about .ab-facts__txt {
  color: var(--slate-300);
  font-size: 0.92rem;
  line-height: 1.65;
}

.page-about .ab-timeline__lead,
.page-about .ab-center__lead,
.page-about .ab-team__lead {
  margin: 14px 0 0;
  max-width: 56ch;
  color: var(--slate-300);
  line-height: 1.8;
}

.page-about .ab-timeline__grid {
  display: grid;
  gap: clamp(22px, 3vw, 36px);
  margin-top: clamp(24px, 3.4vw, 40px);
}

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

.page-about .ab-stage {
  display: grid;
  grid-template-columns: var(--ab-rail) minmax(0, 1fr);
  gap: clamp(10px, 1.6vw, 20px);
  padding-bottom: clamp(16px, 2.2vw, 24px);
}

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

.page-about .ab-stage__rail {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding-top: 4px;
}

.page-about .ab-stage__rail::before {
  content: "";
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan-400);
  box-shadow: 0 0 0 4px rgba(43, 227, 210, 0.14);
  transition: background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .ab-stage__rail::after {
  content: "";
  flex: 1 1 auto;
  width: 1px;
  min-height: 24px;
  background: linear-gradient(180deg, var(--line-strong), var(--line-soft));
}

.page-about .ab-stage:last-child .ab-stage__rail::after {
  display: none;
}

.page-about .ab-stage__no {
  font-size: clamp(0.95rem, 1.8vw, 1.25rem);
  font-weight: 700;
  color: var(--paper-100);
  letter-spacing: 0.06em;
}

.page-about .ab-stage--v4 .ab-stage__rail::before {
  background: var(--amber-500);
  box-shadow: 0 0 0 5px rgba(244, 183, 64, 0.18);
}

.page-about .ab-stage--v4 .ab-stage__no {
  color: var(--amber-500);
}

.page-about .ab-stage__body {
  background: linear-gradient(180deg, var(--ink-700), var(--ink-800));
  border: 1px solid var(--line);
  clip-path: var(--ab-cut);
  padding: clamp(14px, 2vw, 20px) clamp(16px, 2.4vw, 24px);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-stage__body:hover,
.page-about .ab-stage__body[open] {
  border-color: var(--line-strong);
}

.page-about .ab-stage--v4 .ab-stage__body:hover,
.page-about .ab-stage--v4 .ab-stage__body[open] {
  border-color: var(--ab-amber-line);
}

.page-about .ab-stage__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.02rem, 1.8vw, 1.28rem);
  letter-spacing: 0.01em;
  color: var(--paper-100);
}

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

.page-about .ab-stage__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--cyan-400);
  transition: color var(--dur) var(--ease);
}

.page-about .ab-stage__body[open] .ab-stage__summary::after {
  content: "–";
  color: var(--amber-500);
}

.page-about .ab-stage__name {
  display: inline-block;
}

.page-about .ab-stage__body p {
  margin: 12px 0 0;
  color: var(--slate-300);
  line-height: 1.8;
  font-size: 0.94rem;
  max-width: 54ch;
}

.page-about .ab-timeline__aside,
.page-about .ab-paths,
.page-about .ab-team__figure {
  margin: 0;
}

.page-about .ab-timeline__aside .media,
.page-about .ab-paths .media,
.page-about .ab-team__figure .media {
  border: 1px solid var(--line);
  clip-path: var(--ab-cut);
  background: var(--ink-800);
  overflow: hidden;
}

.page-about .ab-timeline__aside .media img,
.page-about .ab-paths .media img,
.page-about .ab-team__figure .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .ab-timeline__aside figcaption,
.page-about .ab-paths figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  line-height: 1.7;
  color: var(--slate-300);
}

.page-about .ab-paths {
  margin-top: clamp(22px, 3vw, 34px);
  border-top: 1px solid var(--line-soft);
  padding-top: clamp(18px, 2.4vw, 26px);
}

.page-about .ab-drawers {
  display: grid;
  gap: clamp(12px, 1.8vw, 18px);
  margin-top: clamp(22px, 3.2vw, 36px);
}

.page-about .ab-drawer {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: clamp(18px, 2.4vw, 26px);
  background: linear-gradient(180deg, var(--ink-700), var(--ink-800));
  border: 1px solid var(--line);
  clip-path: var(--ab-cut);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-drawer:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.page-about .ab-drawer__no {
  margin: 0;
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  color: var(--amber-500);
}

.page-about .ab-drawer h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--paper-100);
}

.page-about .ab-drawer p {
  margin: 0;
  color: var(--slate-300);
  font-size: 0.92rem;
  line-height: 1.78;
}

.page-about .ab-drawer__link {
  margin-top: auto;
  padding-top: 12px;
  align-self: flex-start;
  color: var(--cyan-200);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.92rem;
  padding-bottom: 3px;
  background: linear-gradient(90deg, var(--amber-500), var(--amber-500)) 0 100% / 0 1px no-repeat;
  transition: background-size var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .ab-drawer__link:hover,
.page-about .ab-drawer__link:focus-visible {
  color: var(--amber-300);
  background-size: 100% 1px;
}

.page-about .ab-team__grid {
  display: grid;
  gap: clamp(12px, 1.8vw, 18px);
  margin-top: clamp(22px, 3.2vw, 36px);
}

.page-about .ab-team__card {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px);
  padding-top: calc(clamp(18px, 2.4vw, 26px) + 8px);
  background: var(--ink-800);
  border: 1px solid var(--line);
  clip-path: var(--ab-cut);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-team__card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 34%;
  height: 3px;
  transition: width var(--dur) var(--ease);
}

.page-about .ab-team__card--cyan::before { background: var(--cyan-400); }
.page-about .ab-team__card--amber::before { background: var(--amber-500); }
.page-about .ab-team__card--magenta::before { background: var(--magenta-500); }

.page-about .ab-team__card:hover::before {
  width: 100%;
}

.page-about .ab-team__card:hover {
  border-color: var(--line-strong);
  background: var(--ink-700);
}

.page-about .ab-team__no {
  margin: 0 0 6px;
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  color: var(--slate-300);
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .ab-team__card:hover .ab-team__no {
  transform: translateX(2px);
  color: var(--amber-300);
}

.page-about .ab-team__card h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.08rem, 2vw, 1.3rem);
  color: var(--paper-100);
}

.page-about .ab-team__duty {
  margin: 10px 0 0;
  color: var(--slate-300);
  font-size: 0.92rem;
  line-height: 1.78;
}

.page-about .ab-team__note {
  display: grid;
  gap: clamp(18px, 2.6vw, 32px);
  align-items: center;
  margin-top: clamp(24px, 3.4vw, 40px);
  padding-top: clamp(20px, 2.8vw, 30px);
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-team__note-text p {
  margin: 0;
  color: var(--slate-300);
  line-height: 1.8;
  font-size: 0.95rem;
  max-width: 54ch;
}

.page-about .ab-team__note-text p + p {
  margin-top: 14px;
  padding-left: 14px;
  border-left: 2px solid var(--tint-amber);
}

.page-about .ab-service__grid {
  display: grid;
  gap: clamp(24px, 3.4vw, 40px);
  align-items: start;
}

.page-about .ab-service__text p {
  margin: 14px 0 0;
  color: var(--slate-300);
  line-height: 1.8;
  max-width: 52ch;
}

.page-about .ab-service__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 2.8vw, 28px);
}

.page-about .ab-contact-card {
  padding: clamp(18px, 2.6vw, 28px);
  background:
    linear-gradient(160deg, var(--tint-amber), transparent 62%),
    var(--ink-800);
  border: 1px solid var(--ab-amber-line);
  clip-path: var(--ab-cut);
}

.page-about .ab-contact-card__kicker {
  margin: 0 0 14px;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--amber-300);
}

.page-about .ab-contact-card__list {
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
}

.page-about .ab-contact-card__list > div {
  background: var(--ink-700);
  padding: 12px 14px;
  display: grid;
  gap: 4px;
}

.page-about .ab-contact-card__list dt {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--cyan-200);
}

.page-about .ab-contact-card__list dd {
  margin: 0;
  color: var(--paper-100);
  font-size: 0.95rem;
  line-height: 1.6;
  overflow-wrap: anywhere;
}

.page-about .ab-contact-card__list dd a {
  color: var(--paper-100);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-contact-card__list dd a:hover,
.page-about .ab-contact-card__list dd a:focus-visible {
  color: var(--amber-300);
  border-color: var(--amber-500);
}

.page-about .ab-contact-card__note {
  margin: 14px 0 0;
  font-size: 0.84rem;
  line-height: 1.7;
  color: var(--slate-300);
}

@media (min-width: 720px) {
  .page-about .ab-drawers {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .ab-hero {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .ab-origin__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.85fr);
    gap: clamp(28px, 4vw, 56px);
  }

  .page-about .ab-service__grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.9fr);
  }

  .page-about .ab-team__note {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  }
}

@media (min-width: 960px) {
  .page-about .ab-timeline__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.62fr);
    align-items: start;
  }

  .page-about .ab-timeline__aside {
    position: sticky;
    top: calc(var(--head-h) + 20px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-drawer,
  .page-about .ab-drawer__link,
  .page-about .ab-team__card,
  .page-about .ab-team__no,
  .page-about .ab-quick a,
  .page-about .ab-stage__body,
  .page-about .ab-contact-card__list dd a {
    transition: none;
  }

  .page-about .ab-drawer:hover {
    transform: none;
  }

  .page-about .ab-team__card:hover .ab-team__no {
    transform: none;
  }
}
<<<END>>>