.page-about {
  --chapter-padding-y: 80px;
  --chapter-padding-x: 24px;
  --timeline-gap: 8px;
  --badge-size: 120px;
  --content-max-w: 1200px;
  --col-gap: 48px;
}

/* ====== Breadcrumb ====== */
.page-about .breadcrumb {
  max-width: var(--content-max-w);
  margin: 0 auto;
  padding: 16px var(--chapter-padding-x) 0;
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.85rem;
  color: var(--color-gray, #8D99AE);
}
.page-about .breadcrumb-link {
  color: var(--color-gold, #F5B041);
  text-decoration: none;
  transition: opacity var(--transition-fast, 0.15s);
}
.page-about .breadcrumb-link:hover {
  opacity: 0.7;
}
.page-about .breadcrumb-sep {
  color: var(--color-gray, #8D99AE);
  font-family: var(--font-mono, 'JetBrains Mono', monospace);
}
.page-about .breadcrumb-current {
  color: var(--color-white, #FFFFFF);
  font-weight: 600;
}

/* ====== Story Chapter Shared ====== */
.page-about .story-chapter {
  padding: var(--chapter-padding-y) var(--chapter-padding-x);
  position: relative;
  overflow: hidden;
}
.page-about .story-chapter-inner {
  max-width: var(--content-max-w);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 32px;
  align-items: flex-start;
  position: relative;
  z-index: 1;
}
.page-about .story-chapter-number {
  font-family: var(--font-mono, 'JetBrains Mono', monospace);
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1;
  opacity: 0.15;
  color: currentColor;
  position: absolute;
  top: 0;
  right: 0;
  pointer-events: none;
  user-select: none;
  letter-spacing: -0.04em;
}
.page-about .story-chapter-content {
  flex: 1;
  max-width: 680px;
}
.page-about .story-chapter-heading {
  font-family: 'Inter', system-ui, sans-serif;
  font-weight: 800;
  font-size: 2.2rem;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  line-height: 1.2;
}
.page-about .story-chapter-text {
  font-family: 'Inter', system-ui, sans-serif;
  font-weight: 400;
  line-height: 1.7;
  font-size: 1rem;
  margin: 0 0 16px;
  max-width: 600px;
}
.page-about .story-chapter-text:last-of-type {
  margin-bottom: 0;
}
.page-about .story-chapter-visual {
  width: 100%;
  max-width: 520px;
  margin: 0;
}
.page-about .story-chapter-img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--border-radius-md, 8px);
  background: var(--color-deep-blue, #0B1D3A);
}
.page-about .story-chapter-caption {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.8rem;
  color: var(--color-gray, #8D99AE);
  margin-top: 8px;
  text-align: right;
  letter-spacing: 0.02em;
}
.page-about .story-chapter-cta {
  margin-top: 12px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* ====== Chapter 1: Light ====== */
.page-about .story-chapter--light {
  background: var(--color-white, #FFFFFF);
  color: var(--color-deep-blue, #0B1D3A);
}
.page-about .story-chapter--light .story-chapter-heading {
  color: var(--color-deep-blue, #0B1D3A);
}
.page-about .story-chapter--light .story-chapter-text {
  color: #1a1a2e;
}
.page-about .story-chapter--light .story-chapter-caption {
  color: #5a6a7a;
}

/* ====== Chapter 2: Dark ====== */
.page-about .story-chapter--dark {
  background: var(--gradient-deep-blue, linear-gradient(135deg, #0B1D3A, #162447));
  color: var(--color-white, #FFFFFF);
}
.page-about .story-chapter--dark .story-chapter-heading {
  color: var(--color-gold, #F5B041);
}
.page-about .story-chapter--dark .story-chapter-text {
  color: rgba(255, 255, 255, 0.88);
}
.page-about .story-chapter--dark .story-chapter-caption--light {
  color: rgba(255, 255, 255, 0.6);
}
.page-about .story-chapter--dark .story-chapter-cta {
  color: var(--color-deep-blue, #0B1D3A);
}

/* ====== Version Badge ====== */
.page-about .version-badge {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(245, 176, 65, 0.35);
  border-radius: var(--border-radius-md, 8px);
  padding: 8px 20px 8px 16px;
  margin: 16px 0 20px;
  cursor: default;
  transition: background var(--transition-base, 0.25s), border-color var(--transition-base, 0.25s);
}
.page-about .version-badge:hover {
  background: rgba(245, 176, 65, 0.15);
  border-color: var(--color-gold, #F5B041);
}
.page-about .version-badge-label {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-gray, #8D99AE);
}
.page-about .version-badge-number {
  font-family: var(--font-mono, 'JetBrains Mono', monospace);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-gold, #F5B041);
}

/* ====== Version Timeline ====== */
.page-about .version-timeline {
  list-style: none;
  padding: 0;
  margin: 8px 0 16px;
  display: flex;
  flex-wrap: wrap;
  gap: var(--timeline-gap);
  max-width: 100%;
}
.page-about .version-timeline-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 14px;
  min-width: 70px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius-sm, 4px);
  cursor: pointer;
  transition: background var(--transition-fast, 0.15s), transform var(--transition-fast, 0.15s);
  border: 1px solid transparent;
}
.page-about .version-timeline-item:hover,
.page-about .version-timeline-item:focus-visible {
  background: rgba(245, 176, 65, 0.12);
  border-color: rgba(245, 176, 65, 0.3);
  transform: translateY(-2px);
  outline: none;
}
.page-about .tl-node {
  font-family: var(--font-mono, 'JetBrains Mono', monospace);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-white, #FFFFFF);
  line-height: 1.2;
}
.page-about .tl-node--current {
  color: var(--color-gold, #F5B041);
  position: relative;
}
.page-about .tl-node--current::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background: var(--color-gold, #F5B041);
  border-radius: 1px;
}
.page-about .tl-desc {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.65rem;
  color: rgba(255, 255, 255, 0.55);
  text-align: center;
  line-height: 1.3;
  max-width: 72px;
}
.page-about .story-chapter--dark .story-chapter-cta {
  display: inline-block;
}

/* ====== Chapter 3: Accent (gold) ====== */
.page-about .story-chapter--accent {
  background: var(--color-white, #FFFFFF);
  color: var(--color-deep-blue, #0B1D3A);
  border-top: 4px solid var(--color-gold, #F5B041);
}
.page-about .story-chapter--accent .story-chapter-heading {
  color: var(--color-deep-blue, #0B1D3A);
  position: relative;
  display: inline-block;
}
.page-about .story-chapter--accent .story-chapter-heading::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--color-gold, #F5B041);
  border-radius: 2px;
}
.page-about .story-chapter--accent .story-chapter-text {
  color: #1a1a2e;
}
.page-about .story-chapter--accent .story-chapter-caption {
  color: #5a6a7a;
}

/* ====== Story Links ====== */
.page-about .story-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid rgba(11, 29, 58, 0.1);
}
.page-about .story-links-label {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-deep-blue, #0B1D3A);
  opacity: 0.7;
}
.page-about .story-link {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-deep-blue, #0B1D3A);
  text-decoration: none;
  padding: 4px 14px;
  border: 1px solid var(--color-deep-blue, #0B1D3A);
  border-radius: 100px;
  transition: background var(--transition-fast, 0.15s), color var(--transition-fast, 0.15s);
}
.page-about .story-link:hover {
  background: var(--color-deep-blue, #0B1D3A);
  color: var(--color-white, #FFFFFF);
}

/* ====== Chapter Full-width Visual ====== */
.page-about .story-chapter-visual-full {
  width: 100%;
  margin: 12px 0 0;
  order: 2;
}
.page-about .story-chapter-img-full {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--border-radius-md, 8px);
  background: #0a1628;
}

/* ============================================================ */
/*  Tablet+                                                     */
/* ============================================================ */
@media (min-width: 720px) {
  .page-about {
    --chapter-padding-y: 100px;
    --chapter-padding-x: 40px;
  }
  .page-about .story-chapter-inner {
    flex-direction: row;
    align-items: center;
    gap: var(--col-gap);
  }
  .page-about .story-chapter--dark .story-chapter-inner {
    flex-wrap: wrap;
  }
  .page-about .story-chapter-content {
    flex: 1 1 45%;
  }
  .page-about .story-chapter-visual {
    flex: 1 1 40%;
    max-width: 480px;
  }
  .page-about .story-chapter-visual-full {
    flex: 0 0 100%;
  }
  .page-about .story-chapter-number {
    font-size: 5rem;
    top: 8px;
    right: 12px;
  }
  .page-about .story-chapter-heading {
    font-size: 2.6rem;
  }
  .page-about .version-timeline {
    gap: 10px;
  }
  .page-about .version-timeline-item {
    min-width: 82px;
    padding: 12px 16px;
  }
  .page-about .tl-desc {
    font-size: 0.7rem;
    max-width: 80px;
  }
}

/* ============================================================ */
/*  Desktop                                                     */
/* ============================================================ */
@media (min-width: 1024px) {
  .page-about {
    --chapter-padding-y: 120px;
    --chapter-padding-x: 48px;
    --col-gap: 64px;
  }
  .page-about .story-chapter-heading {
    font-size: 3rem;
  }
  .page-about .story-chapter-text {
    font-size: 1.05rem;
  }
  .page-about .story-chapter-number {
    font-size: 6.5rem;
  }
  .page-about .version-timeline-item {
    min-width: 96px;
    padding: 14px 20px;
  }
  .page-about .tl-node {
    font-size: 1.25rem;
  }
  .page-about .tl-desc {
    font-size: 0.75rem;
    max-width: 90px;
  }
  .page-about .version-badge {
    padding: 10px 24px 10px 18px;
  }
  .page-about .version-badge-number {
    font-size: 1.5rem;
  }
}

/* ============================================================ */
/*  Narrow: ensure no overflow                                  */
/* ============================================================ */
@media (max-width: 480px) {
  .page-about {
    --chapter-padding-y: 48px;
    --chapter-padding-x: 16px;
  }
  .page-about .story-chapter-heading {
    font-size: 1.6rem;
  }
  .page-about .story-chapter-number {
    font-size: 2.8rem;
  }
  .page-about .story-chapter-inner {
    gap: 20px;
  }
  .page-about .version-timeline {
    justify-content: center;
  }
  .page-about .version-timeline-item {
    min-width: 60px;
    padding: 8px 10px;
  }
  .page-about .tl-desc {
    display: none;
  }
  .page-about .version-badge {
    flex-wrap: wrap;
    gap: 8px;
  }
  .page-about .breadcrumb {
    padding-left: 12px;
    padding-right: 12px;
    font-size: 0.75rem;
  }
  .page-about .story-links {
    flex-direction: column;
    align-items: flex-start;
  }
}