.page-about {
  background: var(--paper);
  color: var(--ink);
}

.page-about .about-hero {
  padding-block: clamp(24px, 4vw, 40px) clamp(24px, 3.5vw, 36px);
}

.page-about .breadcrumb {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
  margin-bottom: clamp(20px, 3vw, 32px);
}
.page-about .breadcrumb a {
  color: var(--ink-soft);
  text-decoration: none;
  transition: color 160ms ease;
}
.page-about .breadcrumb a:hover {
  color: var(--vermilion);
}
.page-about .breadcrumb__sep {
  margin-inline: 8px;
  color: var(--line);
}
.page-about .breadcrumb__current {
  color: var(--ink);
  font-weight: 700;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  align-items: end;
}

.page-about .eyebrow {
  color: var(--vermilion);
  font-size: 12px;
  letter-spacing: 0.14em;
  margin: 0 0 12px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.page-about .eyebrow::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--vermilion);
}

.page-about .about-hero__title {
  font-family: var(--font-serif);
  font-size: clamp(30px, 4.8vw, 46px);
  line-height: 1.24;
  letter-spacing: 0.01em;
  color: var(--ink);
  margin: 0 0 18px;
}

.page-about .about-hero__intro {
  font-size: clamp(15px, 1.2vw, 17px);
  line-height: 1.85;
  color: var(--ink-soft);
  margin: 0;
  max-width: 36em;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin: 0;
}
.page-about .about-stats__item {
  background: var(--paper);
  padding: 16px 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}
.page-about .about-stats__item dt {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
  margin: 0;
}
.page-about .about-stats__item dd {
  margin: 0;
  color: var(--vermilion);
  font-size: clamp(22px, 2.6vw, 28px);
  font-weight: 700;
  line-height: 1.05;
}

.page-about .about-hero__media {
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .media-frame {
  border: 1px solid var(--line);
  background: var(--navy);
  overflow: hidden;
  position: relative;
}
.page-about .media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(246, 239, 226, 0.06) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(246, 239, 226, 0.06) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}
.page-about .media-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-body {
  padding-block: clamp(32px, 5vw, 64px) clamp(48px, 6vw, 80px);
}

.page-about .about-layout {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-toc {
  min-width: 0;
}
.page-about .about-toc__label {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ink-soft);
  font-weight: 700;
}
.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .about-toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 10px 12px;
  border-left: 0;
  border-bottom: 2px solid var(--line);
  text-decoration: none;
  color: var(--ink-soft);
  font-size: 13px;
  white-space: nowrap;
  transition: color 160ms ease, border-color 160ms ease;
}
.page-about .about-toc__link:hover {
  color: var(--vermilion);
  border-bottom-color: var(--vermilion);
}
.page-about .about-toc__link[data-current="true"] {
  color: var(--ink);
  border-bottom-color: var(--vermilion);
  font-weight: 700;
}
.page-about .about-toc__num {
  font-size: 12px;
  color: var(--vermilion);
  letter-spacing: 0.06em;
}

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

.page-about .about-chapter {
  border-top: 1px solid var(--line);
  padding-block: clamp(28px, 4.5vw, 56px);
}
.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 20px;
}
.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  color: var(--vermilion);
  line-height: 1;
  letter-spacing: 0.02em;
  flex: none;
}
.page-about .about-chapter__title {
  font-family: var(--font-serif);
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.35;
  color: var(--ink);
  margin: 0;
}

.page-about .prose {
  max-width: 36em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
}
.page-about .prose p {
  margin: 0 0 1em;
}
.page-about .prose p:last-child {
  margin-bottom: 0;
}
.page-about .prose a {
  color: var(--vermilion);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  padding-bottom: 1px;
  transition: color 160ms ease;
}
.page-about .prose a:hover {
  color: var(--vermilion-deep);
}

.page-about .about-chapter__split {
  display: grid;
  gap: clamp(24px, 3.5vw, 40px);
  align-items: start;
}
.page-about .about-chapter__media {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 0;
}

.page-about .plate-diagram {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  background: var(--paper);
  border: 1px solid var(--line);
  border-right: 0;
}
.page-about .plate-diagram__seg {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 20px 10px 18px;
  border-right: 1px solid var(--line);
  border-top: 4px solid transparent;
  text-align: center;
  transition: background 180ms ease, border-top-color 180ms ease;
  cursor: default;
}
.page-about .plate-diagram__seg--zone {
  border-top-color: var(--vermilion);
}
.page-about .plate-diagram__seg--class {
  border-top-color: var(--butter);
}
.page-about .plate-diagram__seg--room {
  border-top-color: var(--navy);
}
.page-about .plate-diagram__seg:hover {
  background: var(--vermilion);
  border-top-color: var(--vermilion);
}
.page-about .plate-diagram__seg:hover .plate-diagram__label,
.page-about .plate-diagram__seg:hover .plate-diagram__value {
  color: var(--butter-pale);
}
.page-about .plate-diagram__label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-soft);
  transition: color 180ms ease;
}
.page-about .plate-diagram__value {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.6vw, 34px);
  font-weight: 700;
  color: var(--ink);
  line-height: 1;
  transition: color 180ms ease;
}
.page-about .about-plate-frame {
  aspect-ratio: 3 / 2;
}

.page-about .about-chapter--navy {
  background: var(--navy);
  color: var(--butter-pale);
  padding-inline: clamp(16px, 3vw, 40px);
  border-top: 0;
}
.page-about .about-chapter--navy .about-chapter__num {
  color: var(--butter);
}
.page-about .about-chapter--navy .about-chapter__title {
  color: var(--butter-pale);
}
.page-about .about-chapter--navy .prose {
  color: var(--butter-pale);
}
.page-about .about-chapter--navy .prose a {
  color: var(--butter);
}
.page-about .about-chapter--navy .prose a:hover {
  color: var(--butter-pale);
}

.page-about .settle-legend {
  list-style: none;
  margin: 20px 0;
  padding: 16px 18px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  border: 1px solid rgba(240, 217, 160, 0.35);
  background: rgba(11, 31, 51, 0.55);
  max-width: 36em;
}
.page-about .settle-legend li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: var(--butter-pale);
}
.page-about .settle-legend__dot {
  flex: none;
  width: 12px;
  height: 12px;
  display: inline-block;
}
.page-about .settle-legend__dot--pending {
  background: var(--line);
}
.page-about .settle-legend__dot--progress {
  background: var(--butter);
}
.page-about .settle-legend__dot--done {
  background: var(--jade);
}

.page-about .about-timeline {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 20px;
}
.page-about .about-timeline__item {
  padding: 18px 0 0;
  border-top: 4px solid var(--line);
  min-width: 0;
}
.page-about .about-timeline__item--a {
  border-top-color: var(--vermilion);
}
.page-about .about-timeline__item--b {
  border-top-color: var(--vermilion-deep);
}
.page-about .about-timeline__item--c {
  border-top-color: var(--butter);
}
.page-about .about-timeline__item--d {
  border-top-color: var(--navy);
}
.page-about .about-timeline__year {
  margin: 0 0 6px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
}
.page-about .about-timeline__title {
  font-family: var(--font-serif);
  font-size: 20px;
  line-height: 1.4;
  color: var(--ink);
  margin: 0 0 8px;
}
.page-about .about-timeline__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .about-history__figure {
  margin: clamp(24px, 4vw, 40px) 0 0;
}
.page-about .about-history__frame {
  aspect-ratio: 7 / 3;
}
.page-about .about-history__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.page-about .about-principles {
  display: grid;
  gap: 0;
  margin-top: 20px;
  border-top: 1px solid var(--line);
}
.page-about .about-principles__item {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  min-width: 0;
}
.page-about .about-principles__index {
  display: inline-block;
  font-size: 13px;
  color: var(--vermilion);
  letter-spacing: 0.1em;
  margin-bottom: 6px;
}
.page-about .about-principles__title {
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.4;
  color: var(--ink);
  margin: 0 0 8px;
}
.page-about .about-principles__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .about-outro {
  margin-top: clamp(24px, 3.5vw, 36px);
  padding: 20px 22px;
  background: var(--butter-pale);
  border-left: 4px solid var(--vermilion);
  max-width: 36em;
}
.page-about .about-outro p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
}
.page-about .about-outro a {
  color: var(--vermilion-deep);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  padding-bottom: 1px;
}
.page-about .about-outro a:hover {
  color: var(--vermilion);
}

@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .settle-legend {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-principles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 32px;
  }
  .page-about .about-principles__item {
    padding: 22px 0;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 48px;
  }
  .page-about .about-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-layout {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 56px;
  }
  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
  }
  .page-about .about-toc__list {
    flex-direction: column;
    gap: 0;
    overflow-x: visible;
  }
  .page-about .about-toc__link {
    display: flex;
    justify-content: flex-start;
    padding: 10px 0 10px 12px;
    border-bottom: 0;
    border-left: 2px solid var(--line);
    margin-bottom: 2px;
    transform: translateX(0);
    transition: color 160ms ease, border-color 160ms ease, transform 160ms ease, padding-left 160ms ease;
  }
  .page-about .about-toc__link:hover {
    color: var(--vermilion);
    border-left-color: var(--vermilion);
  }
  .page-about .about-toc__link[data-current="true"] {
    border-left-color: var(--vermilion);
    border-bottom: 0;
    padding-left: 16px;
    transform: translateX(4px);
  }
  .page-about .about-chapter__split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 40px;
  }
  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
    align-items: start;
  }
  .page-about .about-timeline__item {
    padding: 18px 16px 0 0;
    margin-right: 16px;
  }
  .page-about .about-timeline__item--a {
    margin-top: 0;
  }
  .page-about .about-timeline__item--b {
    margin-top: 40px;
  }
  .page-about .about-timeline__item--c {
    margin-top: 12px;
  }
  .page-about .about-timeline__item--d {
    margin-top: 56px;
  }
  .page-about .about-principles {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
  }
  .page-about .about-principles__item {
    padding: 22px 20px 26px;
    border-bottom: 0;
    border-right: 1px solid var(--line);
  }
  .page-about .about-principles__item:last-child {
    border-right: 0;
  }
}

@media (min-width: 1360px) {
  .page-about .about-layout {
    grid-template-columns: 240px minmax(0, 760px) minmax(0, 1fr);
    gap: 48px;
  }
}
<<<END>>>