.page-about {
  --tl-yr: 48px;
  --tl-node: 28px;
  --tl-gap: 16px;
  --tl-rail: calc(var(--tl-yr) + var(--tl-gap) + (var(--tl-node) / 2));
  background: var(--c-deep);
  color: var(--c-white);
  position: relative;
  isolation: isolate;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(74, 91, 115, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(74, 91, 115, 0.22) 1px, transparent 1px);
  background-size: 44px 44px;
  pointer-events: none;
}

.page-about .about-shell {
  width: min(100% - 40px, var(--shell-w));
  margin-inline: auto;
  position: relative;
}

.page-about .breadcrumbs {
  padding-top: 24px;
}

.page-about [id] {
  scroll-margin-top: 108px;
}

.page-about .about-hero {
  padding: 44px 0 36px;
  border-bottom: 1px solid var(--c-gray);
}

.page-about .about-hero__overline {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--c-faint);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-size: clamp(27px, 5vw, 48px);
  line-height: 1.14;
  letter-spacing: 0.01em;
  max-width: 920px;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 660px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-dim);
}

.page-about .about-hero__meta {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.page-about .about-hero__coord {
  color: var(--c-volt);
}

.page-about .about-hero__since {
  color: var(--c-lake);
}

.page-about .about-chapters {
  margin-inline: 0;
  border-bottom: 1px solid var(--c-gray);
}

.page-about .about-chapters ol {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  gap: 0;
  overflow-x: auto;
}

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

.page-about .about-chapters a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 20px;
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  color: var(--c-dim);
  border-right: 1px solid var(--c-gray);
  transition: background var(--ease), color var(--ease);
}

.page-about .about-chapters li:first-child a {
  border-left: 1px solid var(--c-gray);
}

.page-about .about-chapters a:hover,
.page-about .about-chapters a:focus-visible {
  background: rgba(18, 53, 95, 0.55);
  color: var(--c-white);
}

.page-about .about-chapters span {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-volt);
}

.page-about .about-chapter {
  position: relative;
  padding: 58px 0 64px;
  border-bottom: 1px solid var(--c-gray);
}

.page-about .about-chapter--milestone {
  background:
    linear-gradient(180deg, rgba(18, 53, 95, 0.28), transparent 220px),
    transparent;
}

.page-about .section-header {
  margin-bottom: 32px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px 24px;
}

.page-about .section-header__left {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .section-header .section-index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-volt);
}

.page-about .section-header .section-title {
  margin: 0;
  font-size: clamp(26px, 3.6vw, 34px);
  line-height: 1.2;
  letter-spacing: 0.02em;
}

.page-about .section-header .section-sub {
  font-size: 13px;
  color: var(--c-dim);
  letter-spacing: 0.04em;
}

.page-about .section-header .coord-label {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--c-faint);
}

.page-about .about-chapter__lead {
  margin: 0 0 36px;
  max-width: 760px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--c-dim);
}

.page-about .about-timeline {
  position: relative;
  display: grid;
  gap: 52px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: calc((var(--tl-yr) / 2));
  top: 44px;
  bottom: 24px;
  width: 2px;
  background: repeating-linear-gradient(
    to bottom,
    var(--c-gray) 0,
    var(--c-gray) 6px,
    transparent 6px,
    transparent 12px
  );
  pointer-events: none;
}

.page-about .timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: var(--tl-yr) minmax(0, 1fr);
  gap: var(--tl-gap);
  align-items: start;
}

.page-about .timeline-item__axis {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  z-index: 1;
}

.page-about .timeline-year {
  font-family: var(--font-mono);
  font-size: 19px;
  font-weight: 800;
  font-style: italic;
  line-height: 1;
  text-decoration: none;
  color: var(--c-white);
  background: var(--c-deep);
  padding: 8px 10px;
  border: 1px solid var(--c-gray);
  border-radius: var(--radius);
  transition: color var(--ease), border-color var(--ease), transform var(--ease);
}

.page-about .timeline-year:hover,
.page-about .timeline-year:focus-visible {
  color: var(--c-volt);
  border-color: var(--c-volt);
  transform: translateY(-2px);
}

.page-about .timeline-node {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--c-lake);
  box-shadow: 0 0 0 4px rgba(61, 139, 122, 0.22);
}

.page-about .timeline-node--volt {
  background: var(--c-volt);
  box-shadow: 0 0 0 4px rgba(232, 240, 76, 0.22);
}

.page-about .timeline-item__panel {
  border-radius: var(--radius);
  padding: 24px;
  min-width: 0;
}

.page-about .glass-panel {
  background: var(--c-glass);
  color: var(--c-ink);
  box-shadow: 0 18px 40px rgba(5, 15, 32, 0.24);
}

.page-about .data-panel {
  background: linear-gradient(145deg, rgba(18, 53, 95, 0.96), rgba(10, 30, 63, 0.92));
  color: var(--c-white);
  border: 1px solid rgba(74, 91, 115, 0.55);
}

.page-about .timeline-item__header {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px 14px;
  margin-bottom: 14px;
}

.page-about .timeline-item__header h3 {
  margin: 0;
  font-size: 20px;
  line-height: 1.3;
}

.page-about .timeline-item__header .tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  border-radius: 4px;
  background: var(--c-deep);
  color: var(--c-white);
  border: 1px solid transparent;
}

.page-about .timeline-item__header .tag--volt {
  background: var(--c-volt);
  color: var(--c-deep);
  border-color: var(--c-volt);
}

.page-about .timeline-item__panel p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.75;
}

.page-about .glass-panel p {
  color: #15273f;
}

.page-about .data-panel p {
  color: var(--c-dim);
}

.page-about .about-philosophy {
  margin: 20px 0 4px;
  padding: 16px 18px;
  border-left: 3px solid var(--c-pitch);
  background: rgba(47, 158, 68, 0.08);
}

.page-about .about-philosophy p {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.65;
}

.page-about .timeline-item__facts {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid rgba(74, 91, 115, 0.35);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 28px;
  font-family: var(--font-mono);
  font-size: 13px;
}

.page-about .timeline-item__facts .data-label {
  color: var(--c-faint);
}

.page-about .data-panel .timeline-item__facts .data-label {
  color: rgba(245, 248, 252, 0.55);
}

.page-about .timeline-item__facts .data-value {
  color: var(--c-white);
  font-weight: 600;
}

.page-about .about-feature-list {
  margin: 22px 0 4px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-feature-list li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-white);
}

.page-about .about-feature-list__no {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-volt);
  flex: 0 0 auto;
}

.page-about .capability-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .capability-card {
  border-radius: var(--radius);
  padding: 26px 24px;
  border: 1px solid rgba(74, 91, 115, 0.5);
  transition: transform var(--ease), border-color var(--ease), box-shadow var(--ease);
}

.page-about .capability-card:hover,
.page-about .capability-card:focus-within {
  transform: translateY(-4px);
  border-color: var(--c-volt);
  box-shadow: 0 16px 32px rgba(5, 15, 32, 0.3);
}

.page-about .capability-card h3 {
  margin: 14px 0 8px;
  font-size: 16px;
  letter-spacing: 0.02em;
}

.page-about .capability-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-dim);
}

.page-about .stat-number {
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--c-white);
}

.page-about .stat-number__unit {
  font-size: 17px;
  font-weight: 700;
  margin-left: 4px;
  color: var(--c-volt);
}

.page-about .capability-card:nth-child(1) .stat-number__unit {
  color: var(--c-lake);
}

.page-about .capability-card:nth-child(3) .stat-number__unit {
  color: var(--c-pitch);
}

.page-about .mission-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
}

.page-about .mission-lead {
  margin: 0 0 24px;
  font-size: 18px;
  line-height: 1.75;
  color: var(--c-white);
}

.page-about .mission-list {
  margin: 0 0 28px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .mission-list li {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 16px;
  padding: 16px 18px;
  background: rgba(18, 53, 95, 0.42);
  border-left: 3px solid var(--c-lake);
  border-radius: var(--radius);
  align-items: baseline;
}

.page-about .mission-list__role {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.page-about .mission-list__desc {
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-dim);
}

.page-about .mission-commit {
  padding: 20px 22px;
  background: var(--c-plateau);
  border-radius: var(--radius);
  border: 1px solid rgba(74, 91, 115, 0.5);
}

.page-about .mission-commit__title {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 700;
  color: var(--c-volt);
}

.page-about .mission-commit p {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-dim);
}

.page-about .mission-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 28px;
  font-family: var(--font-mono);
  font-size: 13px;
}

.page-about .mission-contact .data-label {
  color: var(--c-faint);
}

.page-about .mission-contact .data-value {
  color: var(--c-white);
  font-weight: 600;
}

.page-about .about-next {
  padding: 56px 0 72px;
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-next__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 22px;
  text-decoration: none;
  color: var(--c-white);
  background: rgba(18, 53, 95, 0.36);
  border: 1px solid var(--c-gray);
  border-radius: var(--radius);
  transition: transform var(--ease), border-color var(--ease), background var(--ease);
}

.page-about .about-next__item:hover,
.page-about .about-next__item:focus-visible {
  transform: translateY(-3px);
  border-color: var(--c-volt);
  background: rgba(18, 53, 95, 0.7);
}

.page-about .about-next__index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-faint);
}

.page-about .about-next__title {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.5;
}

.page-about .timeline-item:target .timeline-year {
  color: var(--c-volt);
  border-color: var(--c-volt);
}

.page-about .timeline-item:target .timeline-item__panel {
  box-shadow: 0 0 0 2px rgba(232, 240, 76, 0.55);
}

.page-about .image-frame {
  margin: 20px 0 18px;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--c-plateau);
}

.page-about .image-frame img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

@media (min-width: 720px) {
  .page-about {
    --tl-yr: 96px;
  }

  .page-about .about-timeline {
    gap: 64px;
  }

  .page-about .about-timeline::before {
    left: calc(var(--tl-yr) + (var(--tl-node) / 2));
    top: 56px;
    bottom: 32px;
  }

  .page-about .timeline-item {
    grid-template-columns: var(--tl-yr) var(--tl-node) minmax(0, 1fr);
    gap: 0;
  }

  .page-about .timeline-item__axis {
    grid-column: 1 / 3;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding-top: 10px;
  }

  .page-about .timeline-year {
    font-size: 34px;
    border: none;
    background: none;
    padding: 0;
    border-radius: 0;
  }

  .page-about .timeline-node {
    width: 14px;
    height: 14px;
  }

  .page-about .timeline-item__panel {
    padding: 32px;
  }

  .page-about .capability-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
  }

  .page-about .mission-list li {
    grid-template-columns: 120px 1fr;
  }

  .page-about .about-next__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero {
    padding: 64px 0 48px;
  }

  .page-about .about-chapter {
    padding: 72px 0 80px;
  }

  .page-about .about-chapter__lead {
    font-size: 17px;
  }

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

  .page-about .mission-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 48px;
  }

  .page-about .about-next__grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .about-next__item {
    padding: 24px;
  }
}