:root {
  --bg-dark: #0d0c0b;
  --text-light: #f2ede4;
  --text-oat: #e3dacc;
  --text-muted-dark: #87867f;

  --bg-ivory: #faf9f5;
  --text-ink: #141413;
  --text-muted-light: #5e5d59;
  --border-hairline: rgba(20, 20, 19, 0.14);

  --accent-clay: #d97757;
  --accent-amber: #c68b59;
  --accent-olive: #788c5d;
  --accent-sky: #6a9bcc;
  --accent-fig: #c46686;

  --font-serif: 'Newsreader', 'Instrument Serif', Georgia, serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* Strictly non-scrollable single-viewport lock */
html,
body {
  inline-size: 100dvw;
  block-size: 100dvh;
  max-inline-size: 100dvw;
  max-block-size: 100dvh;
  overflow: hidden;
  overscroll-behavior: none;
  background-color: var(--bg-ivory);
  color: var(--text-ink);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

img,
svg {
  display: block;
  max-inline-size: 100%;
}

.sr-svg-filters {
  position: absolute;
  inline-size: 0;
  block-size: 0;
  pointer-events: none;
}

/* Split-Screen Layout with Generous Breathing Room */
.prism-canvas {
  inline-size: 100dvw;
  block-size: 100dvh;
  display: grid;
  grid-template-columns: minmax(320px, 40dvw) minmax(0, 1fr);
  overflow: hidden;
}

/* ==========================================================================
   LEFT PANE: Deep Slate (#0d0c0b) with Vast Negative Space
   ========================================================================== */
.dark-pane {
  background-color: var(--bg-dark);
  color: var(--text-light);
  padding-block: clamp(2.25rem, 5dvh, 4rem);
  padding-inline: clamp(2.25rem, 4.5dvw, 4.5rem);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  overflow: hidden;
}

.pane-top {
  display: flex;
  align-items: safe center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  color: var(--text-muted-dark);
}

.mark-wrap {
  display: flex;
  align-items: safe center;
  gap: 0.65rem;
  color: var(--text-light);
}

.prism-icon {
  inline-size: 20px;
  block-size: 20px;
  aspect-ratio: 1 / 1;
}

.dark-center {
  display: flex;
  flex-direction: column;
  gap: clamp(1.25rem, 3dvh, 2.25rem);
  max-inline-size: 38ch;
}

.eyebrow {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-clay);
}

.display-title {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(3rem, 2rem + 3.6dvw, 5.4rem);
  line-height: 0.96;
  letter-spacing: -0.02em;
  color: var(--text-light);
  filter: url(#lh-type-f);
  display: flex;
  flex-direction: column;
}

.display-title .line-second {
  padding-inline-start: 0.8em;
  font-style: italic;
  color: var(--text-oat);
}

.quiet-lead {
  font-family: var(--font-serif);
  font-size: clamp(0.95rem, 0.82rem + 0.3dvw, 1.15rem);
  line-height: 1.6;
  color: #b0aea5;
}

/* Minimal 3-line Dotted-Leader Index */
.minimal-index {
  margin-block-start: clamp(0.5rem, 1.5dvh, 1.25rem);
  font-family: var(--font-serif);
  font-size: clamp(0.85rem, 0.76rem + 0.2dvw, 0.96rem);
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.index-row {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

.index-row dt {
  color: var(--text-light);
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
}

.idx-n {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted-dark);
}

.index-row .dots {
  flex: 1 1 auto;
  border-block-end: 1px dotted rgba(242, 237, 228, 0.24);
  transform: translateY(-3px);
}

.index-row dd {
  color: var(--text-oat);
}

.pane-bottom {
  display: flex;
  align-items: safe center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  color: var(--text-muted-dark);
}

/* ==========================================================================
   RIGHT PANE: Warm Ivory (#faf9f5) Focused on Open Negative Space
   ========================================================================== */
.ivory-pane {
  background-color: var(--bg-ivory);
  color: var(--text-ink);
  padding-block: clamp(2.25rem, 5dvh, 4rem);
  padding-inline: clamp(2.75rem, 6dvw, 6.5rem);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  overflow: hidden;
}

.ivory-top {
  display: flex;
  align-items: safe center;
  justify-content: space-between;
  padding-block-end: 1.25rem;
  border-block-end: 1px solid var(--border-hairline);
}

.plate-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-muted-light);
}

.spectrum-dots {
  display: flex;
  align-items: safe center;
  gap: 0.5rem;
}

.s-dot {
  inline-size: 8px;
  block-size: 8px;
  border-radius: 50%;
}

.s-dot.clay  { background-color: var(--accent-clay); }
.s-dot.amber { background-color: var(--accent-amber); }
.s-dot.olive { background-color: var(--accent-olive); }
.s-dot.sky   { background-color: var(--accent-sky); }
.s-dot.fig   { background-color: var(--accent-fig); }

/* Centerpiece Open Sketch Stage */
.sketch-stage {
  flex: 1 1 auto;
  min-block-size: 0;
  display: grid;
  place-items: center;
  padding-block: clamp(1rem, 4dvh, 3rem);
}

.prism-sketch {
  inline-size: 100%;
  max-inline-size: 620px;
  max-block-size: 52dvh;
  aspect-ratio: 680 / 380;
  object-fit: contain;
}

.ivory-bottom {
  padding-block-start: 1.25rem;
  border-block-start: 1px solid var(--border-hairline);
  display: flex;
  justify-content: center;
}

.whisper-caption {
  font-family: var(--font-serif);
  font-size: clamp(0.88rem, 0.78rem + 0.22dvw, 1.02rem);
  line-height: 1.6;
  color: var(--text-muted-light);
  max-inline-size: 52ch;
  text-align: center;
}