:root {
  --bion-blue: #2f5e86;
  --bion-blue-soft: rgba(47, 94, 134, 0.12);
  --bion-field: #121418;
  --bion-glimmer: #8cc4ef;
}

:root[data-theme='dark'] {
  --bion-blue: #8cbbe3;
  --bion-blue-soft: rgba(140, 187, 227, 0.1);
  --bion-field: #0b0c0f;
  --bion-glimmer: #a9d6f7;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    --bion-blue: #8cbbe3;
    --bion-blue-soft: rgba(140, 187, 227, 0.1);
    --bion-field: #0b0c0f;
    --bion-glimmer: #a9d6f7;
  }
}

.bion-hero {
  background:
    radial-gradient(circle at 74% 30%, var(--bion-blue-soft), transparent 36%),
    linear-gradient(180deg, color-mix(in srgb, var(--surface) 78%, transparent), transparent);
}

.bion-hero .eyebrow { color: var(--bion-blue); }

.bion-plate figcaption { max-width: 30rem; }

.bion-plate figcaption cite,
.bion-plate figcaption small {
  display: block;
}

.bion-plate figcaption cite {
  margin-top: 0.55rem;
  color: var(--ink);
  font-size: 0.78rem;
  font-style: normal;
}

.bion-plate figcaption small {
  margin-top: 0.28rem;
  color: var(--ink-soft);
  font-size: 0.72rem;
  font-style: normal;
}

.movement-map {
  position: relative;
  z-index: 3;
  color: var(--ink-soft);
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.movement-map__grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
}

.movement-map a {
  display: flex;
  gap: 0.7rem;
  align-items: center;
  min-height: 74px;
  padding: 0.8rem 1rem;
  color: inherit;
  border-right: 1px solid var(--line);
  font-family: var(--body);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: color 160ms ease, background-color 160ms ease;
}

.movement-map a:first-child { border-left: 1px solid var(--line); }

.movement-map a:hover,
.movement-map a:focus-visible {
  color: var(--bion-blue);
  background: var(--bion-blue-soft);
}

.movement-map a span {
  color: var(--gold);
  font-size: 0.63rem;
  font-weight: 600;
  letter-spacing: 0.15em;
}

.bion-movement { scroll-margin-top: 5rem; }

.bion-movement--wash {
  background: color-mix(in srgb, var(--surface) 70%, transparent);
}

.bion-aside {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.05rem;
  color: var(--gold);
}

.bion-number {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.18em;
}

.bion-sigil {
  color: var(--bion-blue);
  font-family: var(--display);
  font-size: 2.4rem;
  line-height: 1;
}

.bion-date {
  color: var(--ink-soft);
  font-family: var(--display);
  font-size: 0.95rem;
  font-style: italic;
}

.source-quote {
  margin: 2.2rem 0;
  padding: 0.2rem 0 0.2rem 1.6rem;
  border-left: 2px solid var(--bion-blue);
}

.source-quote p {
  margin: 0;
  font-family: var(--display);
  font-size: clamp(1.3rem, 2.3vw, 1.6rem);
  line-height: 1.38;
}

.source-quote cite {
  display: block;
  margin-top: 0.8rem;
  color: var(--ink-soft);
  font-family: var(--body);
  font-size: 0.74rem;
  font-style: normal;
  letter-spacing: 0.06em;
}

.source-quote cite em { font-style: italic; }

.open-questions {
  margin: 0 0 1.6rem;
  padding: 0;
  list-style: none;
}

.open-questions li {
  margin: 0;
  padding: 0.9rem 0;
  border-top: 1px solid var(--line);
  font-size: 1.02rem;
}

.open-questions li:last-child { border-bottom: 1px solid var(--line); }

.open-questions strong {
  color: var(--bion-blue);
  font-family: var(--display);
  font-size: 1.15rem;
  font-weight: 600;
}

.bion-interlude blockquote p + p { color: var(--bion-glimmer); }

.bion-interlude .interlude-mark {
  color: var(--bion-glimmer);
  border-color: var(--bion-glimmer);
}

.sources-list {
  margin: 0 0 2rem;
  padding: 0;
  list-style: none;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.sources-list li { margin: 0 0 0.85rem; }

.register-note {
  padding: 1.6rem 0;
  color: var(--on-dark);
  background: var(--plum);
}

.register-note .reading-shell {
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 1.25rem;
  align-items: center;
}

.register-note__mark {
  display: grid;
  place-items: center;
  width: 50px;
  height: 50px;
  color: var(--bion-glimmer);
  border: 1px solid var(--line-light);
  border-radius: 50%;
}

.register-note .eyebrow { margin-bottom: 0.15rem; }

.register-note p:last-child {
  margin: 0;
  color: rgba(248, 244, 233, 0.76);
  font-family: var(--display);
  font-size: 1rem;
  font-style: italic;
}

.author-line {
  margin: 2.4rem 0 0;
  color: var(--ink-soft);
  font-family: var(--display);
  font-size: 1.05rem;
  font-style: italic;
}

@media (max-width: 900px) {
  .movement-map__grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .movement-map a:nth-child(4) { border-left: 1px solid var(--line); }
  .movement-map a:nth-child(-n+3) { border-bottom: 1px solid var(--line); }
}

@media (max-width: 620px) {
  .movement-map__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .movement-map a:nth-child(4) { border-left: 0; }
  .movement-map a:nth-child(odd) { border-left: 1px solid var(--line); }
  .movement-map a:nth-child(-n+4) { border-bottom: 1px solid var(--line); }
  .bion-aside { display: none; }
  .source-quote { padding-left: 1.1rem; }
  .register-note .reading-shell { grid-template-columns: 42px 1fr; }
  .register-note__mark { width: 40px; height: 40px; }
}