/* Upper / Lower Canon: shared, static Learning Hub. */
.hexagram-sequence-page { min-width: 0; }
.sequence-page {
  max-width: 1120px;
  margin: 0 auto;
  padding: 24px 16px 64px;
  color: var(--color-ink-900);
  font-size: 1rem;
  line-height: 1.9;
}
.sequence-page :where(a, summary):focus-visible,
.sequence-skip-link:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-on-light);
  outline-offset: var(--focus-ring-offset);
}
.sequence-skip-link {
  position: fixed;
  z-index: 500;
  top: 12px;
  left: 12px;
  max-width: calc(100vw - 24px);
  min-height: 44px;
  padding: 10px 16px;
  transform: translateY(calc(-100% - 24px));
  border: 1px solid var(--color-gold-decorative);
  border-radius: var(--radius-sm);
  color: var(--color-surface);
  background: var(--color-ai-900);
  font: 700 1rem/1.6 var(--font-gothic);
  text-decoration: underline;
}
.sequence-skip-link:focus { transform: none; }
.sequence-breadcrumb { margin-bottom: 32px; font-size: .875rem; }
.sequence-breadcrumb ol { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; }
.sequence-breadcrumb li { display: flex; align-items: center; gap: 8px; min-width: 0; }
.sequence-breadcrumb a { display: inline-flex; align-items: center; min-height: 44px; }
.sequence-breadcrumb span { color: var(--color-ink-600); }
.sequence-hero { max-width: 720px; padding: 8px 0 32px; border-bottom: 1px solid var(--color-gold-decorative); }
.sequence-marker { color: var(--color-gold-text-on-light); font-size: .9375rem; letter-spacing: .04em; }
.sequence-hero h1 { margin: 12px 0 24px; color: var(--color-ai-900); font: 600 1.75rem/1.5 var(--font-mincho); letter-spacing: .06em; }
.sequence-definition { margin-bottom: 16px; color: var(--color-ai-900); font-weight: 600; }
.sequence-links { display: flex; flex-wrap: wrap; gap: 8px 24px; margin-top: 20px; }
.sequence-links a { display: flex; align-items: center; min-height: 44px; text-decoration: underline; }
.sequence-guide { max-width: 720px; margin: 32px 0 0; padding: 20px; border: 1px solid var(--color-border); border-left: 3px solid var(--color-gold-decorative); border-radius: var(--radius-sm); background: var(--color-washi-100); }
.sequence-guide__label { margin-bottom: 8px; color: var(--color-gold-text-on-light); font-size: .9375rem; font-weight: 600; }
.sequence-section { margin-top: 48px; }
.sequence-section > h2 { margin-bottom: 24px; padding-bottom: 12px; border-bottom: 1px solid var(--color-gold-decorative); color: var(--color-ai-900); font: 600 1.4375rem/1.5 var(--font-mincho); letter-spacing: .03em; }
.sequence-reading { max-width: 720px; }
.sequence-reading p + p { margin-top: 20px; }
.sequence-note { padding-left: 16px; border-left: 2px solid var(--color-border); }
.sequence-overview { display: grid; gap: 0 24px; max-width: 720px; margin-bottom: 24px; padding: 4px 16px; border: 1px solid var(--color-border); border-radius: var(--radius-sm); background: var(--color-washi-100); }
.sequence-overview > div { padding: 12px 0; border-bottom: 1px solid var(--color-border); }
.sequence-overview > div:last-child { border-bottom: 0; }
.sequence-overview dt { color: var(--color-ink-600); font-size: .9375rem; }
.sequence-overview dd { color: var(--color-ai-900); font-weight: 600; }
.sequence-range-nav { margin: 20px 0; }
.sequence-range-nav ul { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; }
.sequence-range-nav a { display: flex; align-items: center; min-height: 44px; padding: 8px 12px; border: 1px solid var(--color-border); border-radius: var(--radius-sm); background: var(--color-surface); font-size: .9375rem; text-decoration: underline; }
.sequence-list-skip { height: 0; }
.sequence-grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 16px; list-style: none; }
.sequence-card { display: grid; grid-template-columns: 64px minmax(0, 1fr); align-items: start; gap: 14px; min-width: 0; padding: 16px; border: 1px solid var(--color-border); border-radius: var(--radius-lg); background: var(--color-surface); }
.sequence-card:focus { outline: var(--focus-ring-width) solid var(--color-focus-on-light); outline-offset: var(--focus-ring-offset); }
.sequence-card__body { min-width: 0; }
.sequence-card__number { color: var(--color-gold-text-on-light); font-size: .9375rem; }
.sequence-card__title { margin: 0; font: 600 1.125rem/1.5 var(--font-mincho); }
.sequence-card__title a { display: block; align-content: center; min-height: 44px; padding: 6px 0; text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: .2em; }
.sequence-card__reading { margin-bottom: 12px; color: var(--color-ink-600); font-size: .9375rem; line-height: 1.6; }
.sequence-card__structure { font-size: .9375rem; line-height: 1.6; }
.sequence-card__structure > div { display: flex; flex-wrap: wrap; gap: 0 8px; }
.sequence-card__structure dt { color: var(--color-ink-600); }
.sequence-card__structure dt::after { content: "："; }
.sequence-hexagram { display: grid; gap: 8px; width: 64px; margin-top: 24px; color: var(--color-ai-900); }
.sequence-hexagram__trigram { display: grid; gap: 4px; }
.sequence-yao { display: flex; justify-content: space-between; width: 64px; height: 5px; }
.sequence-yao::before, .sequence-yao--yin::after { content: ""; display: block; height: 5px; border-radius: 1px; background: currentColor; }
.sequence-yao--yang::before { width: 64px; }
.sequence-yao--yin::before, .sequence-yao--yin::after { width: 26px; }
.sequence-next-links { display: grid; gap: 12px; max-width: 720px; margin-top: 24px; }
.sequence-next-links a { display: block; min-height: 44px; padding: 16px; border: 1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-washi-100); font-family: var(--font-mincho); text-decoration: underline; }
.sequence-cta { max-width: 720px; margin-top: 32px; padding-top: 24px; border-top: 1px solid var(--color-border); }
.sequence-cta a { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; margin-top: 16px; padding: 12px 24px; border: 1px solid var(--color-ai-900); border-radius: var(--radius-sm); color: var(--color-surface); background: var(--color-ai-900); font-weight: 600; text-decoration: underline; }
.sequence-cta a:hover { color: var(--color-surface); }
.sequence-page .sequence-cta a:focus-visible { outline-color: var(--color-focus-on-light); }
.sequence-references { max-width: 720px; margin-top: 32px; padding-top: 16px; border-top: 1px solid var(--color-border); font-size: .9375rem; }
.sequence-references summary { width: fit-content; min-height: 44px; padding: 8px 4px; color: var(--color-ai-900); text-decoration: underline; cursor: pointer; }
.sequence-references ul { padding-left: 24px; }
.sequence-references li { margin-top: 12px; }
@media (min-width: 40rem) {
  .sequence-page { padding-right: 24px; padding-left: 24px; font-size: 1.0625rem; }
  .sequence-hero h1 { font-size: 2.25rem; }
  .sequence-section > h2 { font-size: 1.625rem; }
  .sequence-section { margin-top: 64px; }
  .sequence-overview { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sequence-overview > div:nth-last-child(2) { border-bottom: 0; }
  .sequence-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sequence-card__title { font-size: 1.25rem; }
}
@media (min-width: 65rem) {
  .sequence-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (prefers-reduced-motion: reduce) {
  .sequence-page *, .sequence-page *::before, .sequence-page *::after, .sequence-skip-link { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}
@media (forced-colors: active) {
  .sequence-hexagram { color: CanvasText; }
  .sequence-card { border-color: CanvasText; }
}

/* Brand Visual Polish: assets mark the reading journey; list data stays quiet. */
.sequence-hero {
  position: relative;
  isolation: isolate;
  display: grid;
  max-width: none;
  padding: 28px 20px 32px;
  border-top: 1px solid var(--color-gold-decorative);
  background:
    linear-gradient(105deg, rgba(255, 252, 245, .94), rgba(247, 242, 232, .82)),
    url("/images/assets/bg_washi.png") repeat;
}
.sequence-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  right: 0;
  bottom: 0;
  width: min(100%, 353px);
  height: 74px;
  opacity: .24;
  mask-image: radial-gradient(ellipse at bottom right, #000 15%, transparent 80%);
  background: url("/images/assets/bg_mountain_dark.png") right bottom / 353px 74px no-repeat;
  pointer-events: none;
}
.sequence-hero__copy { position: relative; z-index: 1; min-width: 0; max-width: 720px; }
.sequence-hero h1 { font-size: 2.125rem; letter-spacing: .08em; }
.sequence-hero__motif {
  position: absolute;
  z-index: -1;
  right: 12px;
  bottom: 40px;
  display: block;
  width: min(60%, 240px);
  height: auto;
  opacity: .09;
  pointer-events: none;
}
.sequence-marker { font-family: var(--font-mincho); }
.sequence-definition { padding-left: 14px; border-left: 2px solid var(--color-gold-decorative); }
.sequence-guide {
  max-width: 800px;
  border-color: rgba(183, 146, 67, .48);
  background: linear-gradient(110deg, rgba(255, 252, 245, .97), rgba(247, 242, 232, .88));
}
.sequence-guide--portrait { display: grid; gap: 18px; padding: 20px; }
.sequence-guide--portrait img { display: block; width: 84px; height: auto; justify-self: center; }
.sequence-guide__copy { min-width: 0; }
.sequence-guide__label { font-family: var(--font-mincho); letter-spacing: .05em; }
.sequence-section > h2 {
  position: relative;
  padding-left: 42px;
}
.sequence-section > h2::before {
  content: "";
  position: absolute;
  top: .1em;
  left: 0;
  width: 30px;
  height: 30px;
  opacity: .82;
  background: url("/images/hakke-trigram-plaque.svg") center / contain no-repeat;
  pointer-events: none;
}
.sequence-cta {
  display: grid;
  align-items: center;
  gap: 24px;
  max-width: 800px;
  padding: 24px 20px;
  border: 1px solid rgba(183, 146, 67, .48);
  border-top: 2px solid var(--color-gold-decorative);
  background: linear-gradient(105deg, rgba(255, 252, 245, .98), rgba(247, 242, 232, .84));
}
.sequence-cta__copy { min-width: 0; }
.sequence-cta__motif { display: block; grid-row: 1; width: 54px; height: auto; justify-self: center; }
.sequence-cta a { max-width: 100%; }
@media (min-width: 40rem) {
  .sequence-hero { padding: 40px 32px 44px; }
  .sequence-hero h1 { font-size: 2.75rem; }
  .sequence-guide--portrait { grid-template-columns: 112px minmax(0, 1fr); align-items: end; gap: 28px; padding: 24px 28px 0; }
  .sequence-guide--portrait img { width: 112px; }
  .sequence-guide__copy { padding-bottom: 24px; }
  .sequence-cta { grid-template-columns: minmax(0, 1fr) 62px; gap: 32px; padding: 28px 32px; }
  .sequence-cta__motif { grid-column: 2; grid-row: auto; width: 62px; }
}
@media (min-width: 65rem) {
  .sequence-hero { grid-template-columns: minmax(0, 1fr) 240px; align-items: center; gap: 40px; }
  .sequence-hero__motif { position: relative; z-index: 0; right: auto; bottom: auto; width: 240px; opacity: .28; }
}
@media (forced-colors: active) {
  .sequence-hero__motif, .sequence-hero::after, .sequence-section > h2::before { display: none; }
  .sequence-guide, .sequence-cta { border-color: CanvasText; }
}