.page-about {
  --about-paper: #F2EFE9;
  --about-ink: #0A1628;
  --about-slate: #5C6B7A;
  --about-line: #D9D2C6;
  --about-card: #FFFFFF;
}

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  min-height: 62vh;
  display: flex;
  align-items: flex-end;
  padding: calc(var(--header-height) + 2.5rem) 1.25rem 4rem;
  background: var(--gradient-dark);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  z-index: 0;
  top: 0;
  right: -10%;
  width: 68%;
  height: 100%;
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.5), rgba(76, 42, 107, 0.08));
  clip-path: polygon(18% 0, 100% 0, 84% 100%, 0 86%);
}

.page-about .about-hero::after {
  content: "SINCE 2018";
  position: absolute;
  z-index: 0;
  right: 1rem;
  bottom: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.32em;
  color: rgba(192, 198, 207, 0.45);
}

.page-about .about-hero-grid {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  display: grid;
  gap: 2rem;
}

.page-about .about-hero-copy .breadcrumb {
  margin-bottom: 2rem;
}

.page-about .about-hero-copy .section-tag {
  color: var(--color-accent);
}

.page-about .about-hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.85rem, 4vw, 3rem);
  line-height: 1.1;
  letter-spacing: -0.015em;
  margin: 0.6rem 0 0.4rem;
  color: var(--color-text);
}

.page-about .about-hero-lede {
  font-family: var(--font-mono);
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  letter-spacing: 0.04em;
  color: var(--color-accent);
  margin: 0 0 1.25rem;
}

.page-about .about-hero-desc {
  max-width: 60ch;
  margin: 0;
  color: var(--color-silver);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.page-about .about-hero-index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(192, 198, 207, 0.35);
}

.page-about .about-hero-year {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-silver);
  padding: 0.45rem 0.75rem;
  border: 1px solid rgba(192, 198, 207, 0.32);
  border-radius: 999px;
}

.page-about .about-archive {
  position: relative;
  z-index: 2;
  background-color: var(--about-paper);
  background-image:
    linear-gradient(rgba(10, 22, 40, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(10, 22, 40, 0.035) 1px, transparent 1px);
  background-size: 28px 28px;
  color: var(--about-ink);
  border-radius: 28px 28px 0 0;
  padding: 3rem 1.25rem 4rem;
  box-shadow: 0 -24px 48px rgba(6, 13, 24, 0.3);
}

.page-about .about-rail {
  margin-bottom: 2rem;
}

.page-about .about-rail-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  color: var(--about-slate);
  margin: 0 0 0.75rem;
}

.page-about .about-rail-nav {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 0.5rem;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
}

.page-about .about-rail-nav a {
  flex: 0 0 auto;
  scroll-snap-align: start;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 0.85rem;
  border: 1px solid var(--about-line);
  border-radius: 999px;
  color: var(--about-ink);
  text-decoration: none;
  font-size: 0.875rem;
  white-space: nowrap;
  transition: border-color 0.25s var(--transition-timing), color 0.25s var(--transition-timing);
}

.page-about .about-rail-nav a:hover,
.page-about .about-rail-nav a:focus-visible {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.page-about .about-rail-nav .index-line {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--color-accent);
}

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

.page-about .about-section {
  padding: 2.5rem 0;
  border-top: 1px solid var(--about-line);
  scroll-margin-top: calc(var(--header-height) + 1rem);
}

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

.page-about .about-section-head .section-tag {
  color: var(--color-accent);
}

.page-about .about-section-head h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 2.8vw, 2.25rem);
  letter-spacing: -0.01em;
  line-height: 1.15;
  margin: 0.4rem 0 0.75rem;
  color: var(--about-ink);
}

.page-about .about-section-intro {
  max-width: 62ch;
  margin: 0 0 1.5rem;
  color: var(--about-slate);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.page-about .about-milestone-layout {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-milestones {
  display: flex;
  gap: 1rem;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 0.25rem 0 0.75rem;
  scroll-padding-left: 0.25rem;
  background: transparent;
  border-left: 0;
}

.page-about .about-milestone {
  flex: 0 0 80%;
  min-width: 80%;
  scroll-snap-align: start;
  margin: 0;
  background: var(--about-card);
  border-radius: 1rem;
  padding: 1.25rem;
  box-shadow: 0 8px 24px rgba(10, 22, 40, 0.07);
}

.page-about .about-milestone summary {
  list-style: none;
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  cursor: pointer;
}

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

.page-about .about-milestone summary::marker {
  content: none;
}

.page-about .about-year {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-accent);
}

.page-about .about-milestone summary strong {
  font-size: 1rem;
  font-weight: 500;
  color: var(--about-ink);
  line-height: 1.4;
}

.page-about .about-milestone-arrow {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-accent);
}

.page-about .about-milestone-arrow::before {
  content: "＋";
}

.page-about .about-milestone[open] .about-milestone-arrow::before {
  content: "−";
}

.page-about .about-milestone p {
  margin: 0.75rem 0 0;
  color: var(--about-slate);
  font-size: 0.9375rem;
  line-height: 1.75;
}

.page-about .about-media {
  margin: 0;
}

.page-about .about-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 1rem;
  box-shadow: 0 24px 48px rgba(10, 22, 40, 0.18);
}

.page-about .about-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin: 1.5rem 0 0;
}

.page-about .about-stat {
  background: var(--about-card);
  border-radius: 1rem;
  padding: 1.4rem 1rem 1.2rem;
  text-align: center;
  box-shadow: 0 8px 24px rgba(10, 22, 40, 0.07);
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-heading);
  font-size: clamp(2rem, 6vw, 3.1rem);
  line-height: 1;
  color: var(--about-ink);
}

.page-about .about-stat-unit {
  font-size: 0.5em;
  margin-left: 0.12em;
  color: var(--color-accent);
  font-weight: 600;
}

.page-about .about-stat-label {
  display: block;
  margin-top: 0.6rem;
  font-size: 0.875rem;
  color: var(--about-slate);
}

.page-about .about-scale-copy {
  margin-top: 1.5rem;
  display: grid;
  gap: 1rem;
}

.page-about .about-scale-copy p {
  margin: 0;
  color: var(--about-slate);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.page-about .about-review-layout {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-review-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}

.page-about .about-review-steps li {
  background: var(--about-card);
  border-radius: 1rem;
  padding: 1.25rem;
  display: grid;
  grid-template-columns: 2.6rem 1fr;
  column-gap: 0.9rem;
  box-shadow: 0 8px 24px rgba(10, 22, 40, 0.06);
}

.page-about .about-review-steps .index-line {
  grid-row: 1 / span 2;
  align-self: start;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-accent);
}

.page-about .about-review-steps h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  color: var(--about-ink);
}

.page-about .about-review-steps p {
  margin: 0;
  color: var(--about-slate);
  font-size: 0.9375rem;
  line-height: 1.75;
}

.page-about .about-chinese-grid {
  display: grid;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.page-about .about-chinese-card {
  background: var(--about-card);
  border-radius: 1rem;
  padding: 1.4rem 1.25rem;
  border-top: 3px solid var(--color-terracotta);
  box-shadow: 0 8px 24px rgba(10, 22, 40, 0.06);
}

.page-about .about-chinese-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.2rem;
  height: 2.2rem;
  border-radius: 0.7rem;
  background: var(--color-terracotta);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  margin-bottom: 0.9rem;
}

.page-about .about-chinese-card h3 {
  margin: 0 0 0.45rem;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--about-ink);
}

.page-about .about-chinese-card p {
  margin: 0;
  color: var(--about-slate);
  font-size: 0.9375rem;
  line-height: 1.75;
}

.page-about .about-chinese-lower {
  display: grid;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.page-about .about-chinese-copy p {
  margin: 0 0 1rem;
  color: var(--about-slate);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.page-about .about-chinese-copy a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.page-about .about-outro {
  background: var(--gradient-dark);
  color: var(--color-text);
  padding: 4rem 1.25rem;
  position: relative;
  overflow: hidden;
}

.page-about .about-outro::before {
  content: "";
  position: absolute;
  inset: auto -8% -38% 35%;
  height: 100%;
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.45), rgba(255, 107, 53, 0.02));
  clip-path: polygon(0 0, 100% 0, 76% 100%, 0 72%);
}

.page-about .about-outro-inner {
  position: relative;
  z-index: 1;
  max-width: var(--container-width);
  margin: 0 auto;
}

.page-about .about-outro .section-tag {
  color: var(--color-accent);
}

.page-about .about-outro h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.6rem, 3.4vw, 2.6rem);
  line-height: 1.15;
  margin: 0.5rem 0 1rem;
  color: var(--color-text);
}

.page-about .about-outro p {
  max-width: 68ch;
  margin: 0;
  color: var(--color-silver);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.page-about .about-outro-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 2rem;
}

@media (min-width: 768px) {
  .page-about .about-hero {
    min-height: 74vh;
    padding-left: clamp(1.5rem, 5vw, 4rem);
    padding-right: clamp(1.5rem, 5vw, 4rem);
  }

  .page-about .about-hero-grid {
    grid-template-columns: 1.5fr 1fr;
    align-items: end;
    gap: 3rem;
  }

  .page-about .about-hero-index {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-end;
    border-top: 0;
    border-left: 1px solid rgba(192, 198, 207, 0.35);
    padding: 0 0 0 1.5rem;
    margin-top: 3rem;
  }

  .page-about .about-hero-year {
    border: 0;
    border-radius: 0;
    padding: 0.45rem 0;
    border-bottom: 1px solid rgba(192, 198, 207, 0.18);
    text-align: right;
  }

  .page-about .about-archive {
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: 3rem;
    padding: 4rem clamp(1.5rem, 5vw, 4rem) 5rem;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-height) + 2rem);
    align-self: start;
    margin-bottom: 0;
    padding-top: 0.5rem;
  }

  .page-about .about-rail-nav {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail-nav a {
    border: 0;
    border-left: 2px solid var(--about-line);
    border-radius: 0;
    padding: 0.6rem 0.85rem;
    font-size: 0.9rem;
    white-space: normal;
  }

  .page-about .about-rail-nav a:hover,
  .page-about .about-rail-nav a:focus-visible {
    border-left-color: var(--color-accent);
  }

  .page-about .about-section {
    padding: 3rem 0;
  }

  .page-about .about-milestone-layout,
  .page-about .about-review-layout,
  .page-about .about-chinese-lower {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 2.5rem;
  }

  .page-about .about-milestones {
    display: block;
    overflow: visible;
    padding: 0;
    border-left: 1px solid var(--about-line);
    padding-left: 1.5rem;
  }

  .page-about .about-milestone {
    margin-bottom: 1rem;
    min-width: 0;
    flex: none;
  }

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

  .page-about .about-scale-copy {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }

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

  .page-about .about-outro {
    padding: 5rem clamp(1.5rem, 5vw, 4rem);
  }
}