.page-about {
  --about-rail: 248px;
  --about-line: rgba(53, 242, 192, 0.14);
  display: block;
  background: var(--ink-950);
  color: var(--paper-100);
  font-family: var(--font-mono);
  font-size: 1rem;
  line-height: 1.75;
  padding-bottom: clamp(48px, 8vw, 96px);
  overflow-x: hidden;
}

.page-about .about-hero {
  padding-top: clamp(18px, 3.5vw, 36px);
  padding-bottom: clamp(22px, 4vw, 40px);
}

.page-about .about-hero__kicker {
  margin: 0 0 14px;
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

.page-about .about-hero h1 {
  margin: 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.9rem, 5.2vw, 3.4rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--paper-100);
}

.page-about .about-hero__lede {
  margin: clamp(16px, 3vw, 26px) 0 0;
  max-width: 62ch;
  color: var(--slate-400);
  font-size: 1rem;
  line-height: 1.85;
}

.page-about .about-strip {
  list-style: none;
  margin: clamp(22px, 3.5vw, 34px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-faint);
  border: 1px solid var(--line-faint);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .about-strip li {
  background: var(--ink-900);
  padding: 14px 16px;
  display: grid;
  gap: 6px;
  min-width: 0;
}

.page-about .about-strip__k {
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--slate-400);
}

.page-about .about-strip__v {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1rem;
  color: var(--cyan-400);
  font-variant-numeric: tabular-nums;
}

.page-about .about-banner {
  margin: 0 0 clamp(28px, 5vw, 56px);
}

.page-about .about-banner__frame {
  border-radius: var(--radius-l);
  overflow: hidden;
  border: 1px solid var(--line-faint);
  background: var(--ink-900);
}

.page-about .about-banner__frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

.page-about .about-banner figcaption {
  margin-top: 10px;
  font-size: 0.8125rem;
  color: var(--slate-400);
}

.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  align-items: start;
}

.page-about .about-rail {
  display: grid;
  gap: 14px;
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--line-faint);
  border-radius: var(--radius-m);
  background: var(--glass-cyan);
}

.page-about .about-rail__group {
  padding-top: 12px;
  border-top: 1px solid var(--line-faint);
}

.page-about .about-rail__group:first-of-type {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-rail__group > summary {
  cursor: pointer;
  list-style: none;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--slate-400);
  transition: color var(--t-fast) var(--ease);
}

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

.page-about .about-rail__group > summary::after {
  content: "＋";
  float: right;
  color: var(--jade-500);
}

.page-about .about-rail__group[open] > summary::after {
  content: "－";
  color: var(--cyan-400);
}

.page-about .about-rail__group > summary:hover {
  color: var(--cyan-200);
}

.page-about .about-nav {
  display: grid;
  gap: 2px;
  margin-top: 10px;
}

.page-about .about-nav a {
  position: relative;
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 8px;
  align-items: baseline;
  padding: 8px 10px;
  border-radius: var(--radius-s);
  color: var(--paper-100);
  text-decoration: none;
  font-size: 0.875rem;
  overflow: hidden;
  transition: color var(--t-fast) var(--ease);
}

.page-about .about-nav a::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(90deg, var(--glass-strong), rgba(53, 242, 192, 0));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--t-fast) var(--ease);
}

.page-about .about-nav a > * {
  position: relative;
  z-index: 1;
}

.page-about .about-nav a:hover::before,
.page-about .about-nav a:focus-visible::before {
  transform: scaleX(1);
}

.page-about .about-nav a:hover {
  color: var(--cyan-200);
}

.page-about .about-nav a[aria-current="true"],
.page-about .about-nav a[aria-current="true"] .about-nav__num {
  color: var(--cyan-200);
}

.page-about .about-nav__num {
  font-size: 0.76rem;
  color: var(--cyan-400);
  font-variant-numeric: tabular-nums;
}

.page-about .about-body {
  min-width: 0;
}

.page-about .about-section {
  position: relative;
  padding: clamp(30px, 5vw, 56px) 0 clamp(30px, 5vw, 56px) 20px;
  border-top: 1px solid var(--line-faint);
  scroll-margin-top: 96px;
}

.page-about .about-body > .about-section:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-body > .about-section:first-child::before {
  top: 0;
}

.page-about .about-section::before {
  content: "";
  position: absolute;
  left: 0;
  top: clamp(30px, 5vw, 56px);
  bottom: clamp(30px, 5vw, 56px);
  width: 3px;
  border-radius: var(--radius-pill);
  background: linear-gradient(180deg, var(--jade-700), var(--cyan-400));
  opacity: 0.85;
}

.page-about .about-head {
  display: grid;
  gap: 4px;
  margin-bottom: clamp(16px, 2.5vw, 24px);
}

.page-about .about-num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.3rem, 6vw, 3.5rem);
  line-height: 0.86;
  letter-spacing: -0.03em;
  color: transparent;
  -webkit-text-stroke: 1.5px var(--jade-500);
}

.page-about .about-kicker {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan-400);
}

.page-about .about-head h2 {
  margin: 2px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.3rem, 2.6vw, 1.9rem);
  line-height: 1.26;
  letter-spacing: -0.01em;
  color: var(--paper-100);
}

.page-about .about-text {
  display: grid;
  gap: 14px;
  max-width: 66ch;
}

.page-about .about-text p {
  margin: 0;
}

.page-about .about-text a {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 242, 192, 0.4);
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.page-about .about-text a:hover {
  color: var(--cyan-200);
  border-color: var(--cyan-200);
}

.page-about .about-note {
  color: var(--slate-400);
  font-size: 0.875rem;
}

.page-about .about-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-list li {
  position: relative;
  padding: 13px 16px 13px 36px;
  border: 1px solid var(--line-faint);
  border-radius: var(--radius-s);
  background: var(--ink-900);
  font-size: 0.9375rem;
  transition: border-color var(--t-fast) var(--ease);
}

.page-about .about-list li:hover {
  border-color: var(--cyan-400);
}

.page-about .about-list li::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 22px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan-400);
}

.page-about .about-list li.is-warn::before {
  background: var(--amber-500);
}

.page-about .about-list li.is-warn {
  background: var(--warn-soft);
  border-color: rgba(255, 138, 61, 0.28);
}

.page-about .about-table-wrap {
  margin-top: 24px;
  border: 1px solid var(--line-faint);
  border-radius: var(--radius-m);
  overflow-x: auto;
}

.page-about .data-table {
  width: 100%;
  min-width: 480px;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

.page-about .data-table caption {
  text-align: left;
  padding: 14px 16px 12px;
  color: var(--slate-400);
  font-size: 0.8125rem;
  line-height: 1.6;
}

.page-about .data-table th,
.page-about .data-table td {
  text-align: left;
  padding: 12px 16px;
  border-top: 1px solid var(--line-faint);
  vertical-align: top;
}

.page-about .data-table thead th {
  color: var(--slate-400);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  font-weight: 600;
  text-transform: uppercase;
}

.page-about .data-table tbody tr {
  transition: background var(--t-fast) var(--ease);
}

.page-about .data-table tbody tr:nth-child(even) {
  background: rgba(232, 242, 238, 0.03);
}

.page-about .data-table tbody tr:hover {
  background: rgba(232, 242, 238, 0.08);
}

.page-about .data-table .is-num {
  font-variant-numeric: tabular-nums;
  color: var(--cyan-400);
}

.page-about .glossary {
  display: grid;
  gap: 1px;
  margin: 24px 0 0;
  background: var(--line-faint);
  border: 1px solid var(--line-faint);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .glossary__item {
  margin: 0;
  padding: 18px;
  background: var(--ink-900);
  display: grid;
  gap: 8px;
  transition: background var(--t-fast) var(--ease), box-shadow var(--t-fast) var(--ease);
}

.page-about .glossary__item:hover {
  background: rgba(53, 242, 192, 0.06);
  box-shadow: inset 0 0 0 1px var(--cyan-400);
}

.page-about .glossary dt {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1rem;
  color: var(--cyan-200);
}

.page-about .glossary dd {
  margin: 0;
  color: var(--slate-400);
  font-size: 0.875rem;
  line-height: 1.8;
}

.page-about .about-figure {
  margin: clamp(22px, 4vw, 32px) 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-faint);
  border-radius: var(--radius-m);
  object-fit: cover;
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 0.8125rem;
  color: var(--slate-400);
}

.page-about .about-steps {
  list-style: none;
  counter-reset: step;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
}

.page-about .about-steps li {
  counter-increment: step;
  position: relative;
  padding: 16px 0 16px 46px;
  border-top: 1px solid var(--line-faint);
}

.page-about .about-steps li:first-child {
  border-top: 0;
}

.page-about .about-steps li::before {
  content: "0" counter(step);
  position: absolute;
  left: 0;
  top: 18px;
  width: 36px;
  font-size: 0.85rem;
  color: var(--cyan-400);
  font-variant-numeric: tabular-nums;
}

.page-about .about-steps b {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1rem;
  color: var(--paper-100);
}

.page-about .about-steps span {
  display: block;
  color: var(--slate-400);
  font-size: 0.9rem;
  max-width: 62ch;
}

.page-about .about-quote {
  margin: clamp(22px, 4vw, 30px) 0 0;
  padding: 16px 20px;
  border-left: 4px solid var(--amber-500);
  border-radius: 0 var(--radius-m) var(--radius-m) 0;
  background: var(--glass-cyan);
  color: var(--paper-100);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.page-about .about-quote p {
  margin: 0;
}

.page-about .timeline {
  list-style: none;
  position: relative;
  margin: 26px 0 0;
  padding: 0 0 0 30px;
  display: grid;
  gap: 14px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 16px;
  bottom: 16px;
  width: 2px;
  border-radius: var(--radius-pill);
  background: linear-gradient(180deg, var(--jade-500), var(--cyan-400));
  opacity: 0.7;
}

.page-about .timeline__item {
  position: relative;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 20px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--cyan-400);
  box-shadow: 0 0 0 4px rgba(53, 242, 192, 0.12);
}

.page-about .timeline details {
  border: 1px solid var(--line-faint);
  border-radius: var(--radius-m);
  background: var(--ink-900);
  transition: border-color var(--t-fast) var(--ease);
}

.page-about .timeline details:hover {
  border-color: var(--cyan-400);
}

.page-about .timeline details[open] {
  border-color: rgba(53, 242, 192, 0.45);
}

.page-about .timeline summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 14px 18px;
}

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

.page-about .timeline__ver {
  padding: 2px 10px;
  border: 1px solid rgba(53, 242, 192, 0.35);
  border-radius: var(--radius-pill);
  font-size: 0.78rem;
  color: var(--cyan-400);
  font-variant-numeric: tabular-nums;
}

.page-about .timeline__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1rem;
  color: var(--paper-100);
}

.page-about .timeline__body {
  margin: 0;
  padding: 0 18px 16px;
  color: var(--slate-400);
  font-size: 0.9rem;
  line-height: 1.8;
  max-width: 62ch;
}

@media (min-width: 640px) {
  .page-about .glossary {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .about-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-section {
    padding-left: 30px;
  }

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

  .page-about .timeline__item::before {
    left: -34px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-split {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
  }

  .page-about .about-section {
    padding-left: 36px;
  }

  .page-about .about-text,
  .page-about .about-steps span,
  .page-about .timeline__body {
    max-width: 68ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
    animation: none !important;
  }
}