.page-about {
  --page-pad: max(1.25rem, calc((100vw - 76rem) / 2));
  --page-muted: #8da5bc;
  --page-paper: #f3f6fb;
  --page-blue: #102f52;
  --page-night: #061223;
  --page-line: rgba(138, 155, 176, .32);
  background: linear-gradient(180deg, #0a1a32 0%, #0d2b4d 38%, #102f52 66%, #eaf0f8 100%);
  color: #ffffff;
  font-family: var(--font-body);
  overflow-x: hidden;
  padding-top: 1.75rem;
}

.page-about a {
  text-decoration: none;
}

.page-about .breadcrumbs {
  max-width: 76rem;
  margin-inline: auto;
  padding-inline: var(--page-pad);
  padding-bottom: 1.5rem;
  color: var(--page-muted);
  font-size: .82rem;
}

.page-about .breadcrumbs a {
  color: rgba(255, 255, 255, .72);
}

.page-about .breadcrumbs a:hover {
  color: var(--gold);
}

.page-about .eyebrow {
  color: var(--gold);
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  margin: 0 0 .85rem;
}

.page-about img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
}

.page-about__hero {
  position: relative;
  padding: clamp(3rem, 7vw, 5.6rem) var(--page-pad) 0;
  background: radial-gradient(120% 90% at 80% 10%, rgba(44, 123, 214, .28) 0%, transparent 46%), linear-gradient(135deg, #081a33 0%, #0a1a32 55%, #0d2b4d 100%);
  border-radius: 0 0 40px 40px;
}

.page-about__hero-inner {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
  max-width: 76rem;
  margin-inline: auto;
  align-items: stretch;
}

.page-about__hero-copy {
  max-width: 44rem;
  display: flex;
  flex-direction: column;
}

.page-about__hero h1 {
  font-family: var(--font-title);
  font-size: clamp(2.6rem, 7vw, 5.4rem);
  line-height: 1.06;
  letter-spacing: -.02em;
  margin: 0 0 1.5rem;
  max-width: 12ch;
}

.page-about__hero-lead {
  font-size: clamp(1.02rem, 2vw, 1.45rem);
  line-height: 1.75;
  color: var(--white-soft);
  max-width: 38rem;
  margin: 0 0 2rem;
}

.page-about__hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .9rem;
  align-items: center;
}

.page-about__hero-mark {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: .4rem;
  padding-bottom: 1rem;
}

.page-about__hero-mark-ver {
  font-family: var(--font-title);
  font-size: clamp(6rem, 22vw, 15rem);
  line-height: .82;
  letter-spacing: -.04em;
  background: linear-gradient(160deg, rgba(255, 255, 255, .96) 30%, rgba(138, 155, 176, .72) 80%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.page-about__hero-mark-label {
  font-family: var(--font-mono);
  font-size: .82rem;
  letter-spacing: .16em;
  color: var(--page-muted);
  text-transform: uppercase;
}

.page-about__hero .flag-bar {
  margin-inline: calc(-1 * var(--page-pad));
  margin-top: clamp(2rem, 5vw, 4rem);
}

.page-about__chapter {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem 2rem;
  max-width: 76rem;
  margin-inline: auto;
  padding: clamp(4.5rem, 10vw, 7.5rem) var(--page-pad);
}

.page-about__rail {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.page-about__ch-num {
  font-family: var(--font-title);
  font-size: clamp(4rem, 14vw, 8.5rem);
  line-height: .9;
  letter-spacing: -.02em;
  color: var(--gold);
  opacity: .9;
}

@supports (-webkit-text-stroke: 2px var(--gold)) {
  .page-about__ch-num {
    color: transparent;
    -webkit-text-stroke: 2px var(--gold);
  }
}

.page-about__ch-rule {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, var(--gold), transparent);
}

.page-about__content {
  min-width: 0;
}

.page-about__chapter h2 {
  font-family: var(--font-title);
  font-size: clamp(1.8rem, 4vw, 3.1rem);
  line-height: 1.18;
  letter-spacing: -.02em;
  margin: 0 0 1.2rem;
}

.page-about__chapter--intro,
.page-about__chapter--version {
  color: #ffffff;
}

.page-about__lead {
  font-size: 1.12rem;
  line-height: 1.78;
  color: rgba(255, 255, 255, .9);
  margin: 0 0 1.5rem;
  max-width: 44rem;
}

.page-about__prose {
  display: grid;
  gap: 1rem;
  max-width: 44rem;
  margin-bottom: 2rem;
}

.page-about__prose p,
.page-about__panel-list-note,
.page-about__timeline-desc,
.page-about__flow-card p,
.page-about__nav-card p,
.page-about__boundary-item li,
.page-about__boundary-contact p,
.page-about__culture-closing,
.page-about__nav-closing {
  font-size: .96rem;
  line-height: 1.75;
  opacity: .92;
}

.page-about__intro-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.4rem;
  margin-top: 1.2rem;
}

.page-about__workbench {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  object-fit: cover;
}

.page-about__panel-list {
  background: linear-gradient(160deg, rgba(255, 255, 255, .08), rgba(255, 255, 255, .03));
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  padding: 1.5rem 1.6rem;
  align-self: start;
}

.page-about__panel-list-title {
  font-size: .92rem;
  letter-spacing: .08em;
  color: var(--gold);
  margin: 0 0 .8rem;
  font-weight: 700;
}

.page-about__panel-list-content {
  list-style: none;
  margin: 0 0 .9rem;
  padding: 0;
  display: grid;
  gap: .55rem;
}

.page-about__panel-list-content li {
  font-family: var(--font-mono);
  font-size: .96rem;
  color: #ffffff;
  position: relative;
  padding-left: 1.2rem;
}

.page-about__panel-list-content li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: .5rem;
  height: .5rem;
  border-radius: 50%;
  background: var(--accent);
}

.page-about__panel-list-note {
  color: var(--page-muted);
  margin: 0;
}

.page-about__timeline {
  list-style: none;
  padding: 0;
  margin: 0 0 2rem;
  position: relative;
}

.page-about__timeline-item {
  position: relative;
  padding-left: 1.6rem;
  margin-bottom: .8rem;
}

.page-about__timeline-item::before {
  content: "";
  position: absolute;
  left: .32rem;
  top: .9rem;
  width: .72rem;
  height: .72rem;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid rgba(255, 255, 255, .28);
}

.page-about__timeline-item--current::before {
  background: var(--accent);
}

.page-about__timeline-item::after {
  content: "";
  position: absolute;
  left: .63rem;
  top: 1.8rem;
  bottom: -.9rem;
  width: 2px;
  background: linear-gradient(180deg, rgba(242, 198, 109, .7), rgba(138, 155, 176, .14));
}

.page-about__timeline-item:last-child::after {
  display: none;
}

.page-about__timeline-item details {
  margin: 0;
}

.page-about__timeline-item summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .8rem 1rem;
  cursor: pointer;
  list-style: none;
}

.page-about__timeline-item summary::-webkit-details-marker {
  display: none;
}

.page-about__timeline-item[open] summary .page-about__timeline-title {
  color: #ffffff;
}

.page-about__timeline-card {
  background: rgba(255, 255, 255, .055);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  padding: .85rem 1.1rem;
}

.page-about__timeline-ver {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1rem;
  color: var(--gold);
}

.page-about__timeline-item--current .page-about__timeline-ver {
  color: var(--accent);
}

.page-about__timeline-title {
  font-family: var(--font-title);
  font-size: 1.08rem;
  letter-spacing: .01em;
  color: var(--white-soft);
}

.page-about__timeline-desc {
  color: var(--white-soft);
  max-width: 42rem;
  margin: .6rem 0 0;
}

.page-about__version-map {
  width: 100%;
  max-width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-heavy);
  margin-top: .6rem;
}

.page-about__flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: .9rem;
  margin-bottom: 1.4rem;
}

.page-about__flow-card {
  background: rgba(255, 255, 255, .07);
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-lg);
  padding: 1.6rem 1.4rem;
}

.page-about__flow-step {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .82rem;
  color: var(--accent);
  border: 1px solid rgba(246, 74, 55, .5);
  border-radius: var(--radius-pill);
  padding: .25rem .7rem;
  margin-bottom: .9rem;
}

.page-about__flow-card h3 {
  font-family: var(--font-title);
  font-size: 1.3rem;
  margin: 0 0 .5rem;
}

.page-about__flow-arrow {
  font-size: 1.4rem;
  color: var(--page-muted);
  transform: rotate(90deg);
  justify-self: center;
}

.page-about__flow-note {
  border-radius: var(--radius-md);
  padding: .6rem;
}

.page-about__flow-note svg {
  width: 100%;
  max-width: 640px;
  height: auto;
  display: block;
  margin-inline: auto;
}

.page-about__flow-note svg text {
  fill: rgba(255, 255, 255, .72);
  font-size: 12px;
  font-family: var(--font-mono);
}

.page-about__flow-note p {
  max-width: 40rem;
  margin-inline: auto;
  text-align: center;
  font-size: .9rem;
  color: var(--page-muted);
  line-height: 1.7;
}

.page-about__chapter--nav,
.page-about__chapter--boundary {
  background: var(--page-paper);
  color: var(--text-dark);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  margin-inline: var(--page-pad);
  margin-block: 3.5rem;
  padding: clamp(3rem, 7vw, 5.5rem) clamp(1.25rem, 5vw, 4rem);
  max-width: 72rem;
}

.page-about__chapter--nav .eyebrow,
.page-about__chapter--boundary .eyebrow {
  color: var(--cinnabar);
}

.page-about__chapter--nav h2,
.page-about__chapter--boundary h2 {
  color: var(--text-dark);
}

.page-about__chapter--nav .page-about__lead,
.page-about__chapter--boundary .page-about__lead {
  color: rgba(10, 26, 50, .82);
}

.page-about__chapter--nav .page-about__ch-num,
.page-about__chapter--boundary .page-about__ch-num {
  -webkit-text-stroke: 2px var(--cinnabar);
}

.page-about__nav-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin: 2rem 0 1.6rem;
}

.page-about__nav-card {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.5rem 1.4rem;
  position: relative;
  overflow: hidden;
}

.page-about__nav-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--data-blue);
}

.page-about__nav-card--event::before {
  background: var(--accent);
}

.page-about__nav-card--tool::before {
  background: var(--gold);
}

.page-about__nav-card--topic::before {
  background: var(--success);
}

.page-about__nav-index {
  font-family: var(--font-mono);
  font-size: .78rem;
  color: var(--text-muted);
  letter-spacing: .1em;
}

.page-about__nav-card h3 {
  font-family: var(--font-title);
  font-size: 1.35rem;
  margin: .6rem 0 .5rem;
  color: var(--text-dark);
}

.page-about__nav-card p {
  color: rgba(10, 26, 50, .78);
}

.page-about__nav-closing {
  color: rgba(10, 26, 50, .82);
  max-width: 42rem;
  margin: 0;
}

.page-about__culture-image {
  width: 100%;
  max-width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-heavy);
  margin: 1.8rem 0;
  object-fit: cover;
}

.page-about__culture-detail {
  border: 1px solid var(--border-dark);
  border-radius: var(--radius-md);
  padding: 1rem 1.2rem;
  margin-bottom: 1.4rem;
  background: rgba(255, 255, 255, .045);
}

.page-about__culture-detail summary {
  font-weight: 700;
  font-size: .95rem;
  color: var(--gold);
  cursor: pointer;
  margin-bottom: .6rem;
}

.page-about__culture-schemes {
  display: flex;
  flex-direction: column;
  gap: .8rem;
}

.page-about__culture-scheme {
  display: flex;
  align-items: flex-start;
  gap: .8rem;
}

.page-about__culture-scheme p {
  margin: 0;
  color: var(--white-soft);
  font-size: .9rem;
  line-height: 1.6;
}

.page-about__culture-swatch {
  flex: 0 0 auto;
  width: 1.1rem;
  height: 1.1rem;
  border-radius: 50%;
  margin-top: .2rem;
}

.page-about__culture-swatch--default {
  background: linear-gradient(135deg, #0a1a32 40%, #f3f6fb 60%, #f64a37 65%);
}

.page-about__culture-swatch--warm {
  background: linear-gradient(135deg, #f2c66d 20%, #2c7bd6 35%, #2fae78 50%, #c93a2b 65%, #ffffff 80%);
}

.page-about__culture-closing {
  color: var(--white-soft);
  max-width: 42rem;
}

.page-about__boundary-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.2rem;
  margin: 2rem 0 1.6rem;
}

.page-about__boundary-item {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.6rem 1.6rem 1.8rem;
}

.page-about__boundary-item h3 {
  font-family: var(--font-title);
  font-size: 1.25rem;
  margin: 0 0 .9rem;
  color: var(--text-dark);
}

.page-about__boundary-item--do h3 {
  color: var(--success);
}

.page-about__boundary-item--refrain h3 {
  color: var(--cinnabar);
}

.page-about__boundary-item ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .6rem;
}

.page-about__boundary-item li {
  color: rgba(10, 26, 50, .8);
  padding-left: 1.3rem;
  position: relative;
}

.page-about__boundary-item--do li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: .45rem;
  height: .45rem;
  border-radius: 50%;
  background: var(--success);
}

.page-about__boundary-item--refrain li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: .45rem;
  height: .45rem;
  border-radius: 50%;
  background: var(--cinnabar);
}

.page-about__boundary-contact {
  background: rgba(10, 26, 50, .05);
  border-radius: var(--radius-md);
  padding: 1.3rem 1.4rem;
  display: grid;
  gap: .7rem;
}

.page-about__boundary-contact p {
  color: var(--text-dark);
  margin: 0;
}

.page-about__boundary-contact a {
  color: var(--data-blue);
  font-weight: 600;
}

.page-about__next {
  background: linear-gradient(150deg, #0a1a32 0%, #0d2b4d 58%, #102f52 100%);
  padding: clamp(4rem, 9vw, 7rem) var(--page-pad);
  border-radius: 40px 40px 0 0;
  text-align: center;
}

.page-about__next-inner {
  max-width: 44rem;
  margin-inline: auto;
}

.page-about__next .eyebrow {
  justify-content: center;
}

.page-about__next-title {
  font-family: var(--font-title);
  font-size: clamp(1.9rem, 4.5vw, 3.2rem);
  line-height: 1.2;
  margin: 0 0 2rem;
  color: #ffffff;
}

.page-about__next-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .9rem;
}

@media (min-width: 48rem) {
  .page-about .breadcrumbs {
    padding-inline: var(--page-pad) calc(var(--page-pad) + 4rem);
  }

  .page-about__hero {
    border-radius: 0 0 60px 60px;
  }

  .page-about__hero-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .page-about__hero-copy {
    max-width: 42rem;
  }

  .page-about__hero-mark {
    align-items: flex-end;
    padding-bottom: 1.4rem;
    margin-left: 2rem;
  }

  .page-about__chapter {
    grid-template-columns: minmax(6rem, 9.5rem) minmax(0, 1fr);
    gap: clamp(1.5rem, 4vw, 4.5rem);
  }

  .page-about__rail {
    align-items: flex-end;
  }

  .page-about__ch-rule {
    width: 4rem;
    flex: 0 0 auto;
    height: 2px;
    margin-bottom: .4rem;
  }

  .page-about__intro-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, .85fr);
    align-items: start;
  }

  .page-about__workbench {
    min-height: 320px;
  }

  .page-about__flow {
    grid-template-columns: 1fr auto 1fr auto 1fr;
    gap: 1rem;
  }

  .page-about__flow-arrow {
    transform: none;
  }

  .page-about__nav-grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about__boundary-grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about__culture-schemes {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .page-about__chapter--nav,
  .page-about__chapter--boundary {
    margin-inline: auto;
    width: calc(100% - 2 * var(--page-pad));
  }

  .page-about__next {
    border-radius: 60px 60px 0 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .page-about__chapter,
  .page-about .page-about__hero,
  .page-about .page-about__next {
    transition: none;
    animation: none;
  }
}