.page-about {
  --ab-line: 1px solid #17423A;
  --ab-strong: 1px solid #2BF0C4;
  background: #0C0F0E;
  color: #C6D3CE;
}

.page-about .ab-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 46px);
  padding-top: clamp(24px, 4vw, 56px);
  padding-bottom: clamp(30px, 5vw, 64px);
  border-bottom: var(--ab-line);
}

.page-about .ab-hero__copy { min-width: 0; }

.page-about .ab-hero__title {
  margin: 14px 0 20px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.15rem, 6.4vw, 4.1rem);
  line-height: 0.98;
  letter-spacing: -0.022em;
  color: #F6F8F7;
}

.page-about .ab-hero__title::first-line { color: #F6F8F7; }

.page-about .ab-hero__lead {
  margin: 0;
  max-width: 56ch;
  font-size: 16.5px;
  line-height: 1.72;
  color: #C6D3CE;
}

.page-about .ab-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-fact {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: var(--ab-line);
  font-size: 13px;
  line-height: 1.4;
  color: #A9B7B2;
}

.page-about .ab-fact b {
  font-family: var(--font-mono);
  font-size: 19px;
  font-weight: 600;
  color: #2BF0C4;
}

.page-about .ab-hero__media {
  position: relative;
  margin: 0;
  min-width: 0;
}

.page-about .ab-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border: var(--ab-line);
  filter: saturate(0.85) contrast(1.05);
}

.page-about .ab-hero__tag {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 2;
  margin: 0;
  padding: 6px 12px;
  background: #EDE8DA;
  color: #0E2B25;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.page-about .ab-hero__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: #A9B7B2;
  border-left: var(--ab-strong);
  padding-left: 10px;
}

.page-about .ab-flow {
  display: block;
  padding-bottom: clamp(40px, 7vw, 88px);
}

.page-about .ab-sec {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  padding-block: clamp(30px, 5vw, 58px);
  border-bottom: var(--ab-line);
}

.page-about .ab-sec__num {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.12em;
  color: #2BF0C4;
}

.page-about .ab-sec__num::before {
  content: "";
  display: inline-block;
  width: 18px;
  height: 1px;
  margin-right: 8px;
  vertical-align: middle;
  background: #2BF0C4;
}

.page-about .ab-sec__main { min-width: 0; }

.page-about .ab-sec__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.45rem, 3.6vw, 2.15rem);
  line-height: 1.12;
  letter-spacing: -0.012em;
  color: #F6F8F7;
}

.page-about .ab-sec__main p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.72;
  max-width: 62ch;
}

.page-about .ab-sec--band {
  background: #0E2B25;
  padding-inline: clamp(14px, 3vw, 26px);
}

.page-about .ab-scenes {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: #17423A;
  border: var(--ab-line);
}

.page-about .ab-scenes li {
  background: #0C0F0E;
  padding: 13px 15px;
  font-size: 15px;
  line-height: 1.65;
}

.page-about .ab-scenes__k {
  display: block;
  margin-bottom: 3px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: #FF6A2B;
}

.page-about .ab-aside {
  min-width: 0;
  padding-top: 12px;
  border-top: var(--ab-line);
  font-size: 14px;
  line-height: 1.68;
  color: #A9B7B2;
}

.page-about .ab-aside p { margin: 0 0 10px; }

.page-about .ab-aside__num {
  font-family: var(--font-mono);
  font-size: 40px;
  line-height: 1;
  font-weight: 600;
  color: #FF6A2B;
  letter-spacing: -0.02em;
}

.page-about .ab-aside__note {
  color: #A9B7B2;
  border-left: 2px solid #17423A;
  padding-left: 12px;
}

.page-about .ab-aside--photo img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border: var(--ab-line);
  margin-bottom: 12px;
  filter: saturate(0.8);
}

.page-about .ab-banner {
  margin: 20px 0 24px;
}

.page-about .ab-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  border: var(--ab-line);
  filter: grayscale(0.25) contrast(1.05);
}

.page-about .ab-banner figcaption {
  margin-top: 10px;
  font-size: 13px;
  color: #A9B7B2;
}

.page-about .ab-nodes {
  display: grid;
  gap: 8px;
}

.page-about .ab-node {
  border: var(--ab-line);
  background: rgba(23, 66, 58, 0.22);
}

.page-about .ab-node[open] {
  border-color: #17A98C;
  background: #0C0F0E;
}

.page-about .ab-node__head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 13px 14px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-node__idx {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: #2BF0C4;
  flex: none;
}

.page-about .ab-node__ttl {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.35;
  color: #F6F8F7;
  min-width: 0;
}

.page-about .ab-node__hint {
  margin-left: auto;
  flex: none;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: #A9B7B2;
}

.page-about .ab-node__hint::after { content: "展开"; }
.page-about .ab-node[open] .ab-node__hint::after { content: "收起"; }
.page-about .ab-node[open] .ab-node__hint { color: #FF6A2B; }

.page-about .ab-node p {
  margin: 0;
  padding: 0 14px 14px;
  font-size: 14.5px;
  line-height: 1.7;
  color: #C6D3CE;
  border-top: 1px dashed #17423A;
  padding-top: 12px;
}

.page-about .ab-blocks {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: #17423A;
  border: var(--ab-line);
}

.page-about .ab-block {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 10px;
  padding: 15px 15px 16px;
  background: #0C0F0E;
}

.page-about .ab-block__n {
  font-family: var(--font-mono);
  font-size: 13px;
  color: #2BF0C4;
  padding-top: 3px;
}

.page-about .ab-block__t {
  margin: 0 0 5px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.3;
  color: #F6F8F7;
}

.page-about .ab-block__d {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: #C6D3CE;
}

.page-about .ab-block__d a,
.page-about .ab-inline-link,
.page-about .ab-links a {
  color: #2BF0C4;
  text-decoration: none;
  border-bottom: 1px solid #17A98C;
  transition: color 160ms ease, border-color 160ms ease;
}

.page-about .ab-block__d a:hover,
.page-about .ab-inline-link:hover,
.page-about .ab-links a:hover,
.page-about .ab-block__d a:focus-visible,
.page-about .ab-inline-link:focus-visible,
.page-about .ab-links a:focus-visible {
  color: #FF6A2B;
  border-color: #FF6A2B;
}

.page-about .ab-inline-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.03em;
  padding-bottom: 2px;
}

.page-about .ab-quote {
  margin: clamp(28px, 4vw, 44px) 0;
  padding: clamp(24px, 4vw, 44px) clamp(20px, 3.5vw, 40px);
  background: #EDE8DA;
  color: #0E2B25;
  border: 1px solid #0E2B25;
  box-shadow: 6px 6px 0 0 #0E2B25;
}

.page-about .ab-quote p {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-size: clamp(1.12rem, 2.6vw, 1.6rem);
  line-height: 1.5;
  letter-spacing: -0.005em;
}

.page-about .ab-quote cite {
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: #17423A;
}

.page-about .ab-dots {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: 6px;
  max-width: 340px;
  margin: 20px 0 12px;
}

.page-about .ab-dot {
  display: block;
  aspect-ratio: 1;
  background: #17423A;
  border: 1px solid transparent;
  transition: background 160ms ease, border-color 160ms ease;
}

.page-about .ab-dot--on {
  background: #2BF0C4;
}

.page-about .ab-dot:hover { border-color: #2BF0C4; }

.page-about .ab-dots__legend {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: #A9B7B2;
}

.page-about .ab-dots__key {
  flex: none;
  width: 12px;
  height: 12px;
  background: #2BF0C4;
}

.page-about .ab-links {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: #17423A;
  border: var(--ab-line);
}

.page-about .ab-links li {
  background: #0C0F0E;
  padding: 13px 15px;
  font-size: 14.5px;
  line-height: 1.6;
}

.page-about .ab-next {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: clamp(32px, 5vw, 56px);
  padding: clamp(20px, 3.5vw, 32px);
  background: #0E2B25;
  border: var(--ab-line);
  border-left: 3px solid #2BF0C4;
}

.page-about .ab-next__lead {
  width: 100%;
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: #A9B7B2;
}

.page-about .ab-next .kit-btn {
  text-decoration: none;
}

@media (min-width: 760px) {
  .page-about .ab-nodes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-dots {
    max-width: 420px;
    gap: 8px;
  }
}

@media (min-width: 960px) {
  .page-about .ab-hero {
    grid-template-columns: minmax(0, 1fr) minmax(0, 360px);
    align-items: end;
  }
  .page-about .ab-sec {
    grid-template-columns: 74px minmax(0, 1fr) 250px;
    gap: clamp(18px, 2.4vw, 36px);
    align-items: start;
  }
  .page-about .ab-sec__num {
    font-size: 22px;
    border-left: var(--ab-line);
    padding-left: 14px;
    min-height: 54px;
  }
  .page-about .ab-sec__num::before { display: none; }
  .page-about .ab-aside {
    position: sticky;
    top: calc(var(--bar-h) + 20px);
  }
  .page-about .ab-sec--band {
    padding-inline: clamp(20px, 3vw, 34px);
  }
}

@media (min-width: 1180px) {
  .page-about .ab-sec {
    grid-template-columns: 84px minmax(0, 1fr) 280px;
  }
  .page-about .ab-blocks {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-block {
    grid-template-columns: 38px minmax(0, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-dot,
  .page-about .ab-block__d a,
  .page-about .ab-inline-link,
  .page-about .ab-links a {
    transition: none;
  }
}
<<<END>>>