/* ─── Prism landing — an optician's restoration dossier ───
   night watch (dark, default) & daylight ledger (light) */
:root {
  --obsidian: #0C0A08;
  --panel: #171310;
  --panel-edge: #2A2118;
  --brass: #C9A25C;
  --brass-dim: #8A6F3E;
  --parchment: #EDE4D3;
  --parchment-dim: #B0A58E;
  --hero-top: #1A1610;
  --star: #EDE4D3;
  --beam-in: #EDE4D3;
  --title-glow: rgba(201, 162, 92, 0.25);
  --shot-shadow: rgba(0, 0, 0, 0.55);
  --vignette: rgba(5, 4, 3, 0.5);
  --board: #12100C;
}

[data-theme="light"] {
  --obsidian: #F1EADA;
  --panel: #FAF5E9;
  --panel-edge: #D9CDB0;
  --brass: #8A6F3E;
  --brass-dim: #AD9868;
  --parchment: #2A2318;
  --parchment-dim: #6E6350;
  --hero-top: #FBF6E9;
  --star: #8A6F3E;
  --beam-in: #6E5A33;
  --title-glow: rgba(138, 111, 62, 0.25);
  --shot-shadow: rgba(96, 78, 40, 0.28);
  --vignette: rgba(120, 100, 60, 0.14);
  --board: #EFE7D3;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--obsidian);
  color: var(--parchment);
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background 0.35s ease, color 0.35s ease;
}

img { max-width: 100%; display: block; }

/* film grain + vignette */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 50;
  opacity: 0.05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)'/%3E%3C/svg%3E");
}
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 49;
  background: radial-gradient(ellipse 90% 80% at 50% 40%, transparent 60%, var(--vignette));
}

/* light spine — the beam travels down the record as you read */
.light-spine {
  position: fixed;
  top: 0;
  bottom: 0;
  left: max(0.9rem, calc((100vw - 1060px) / 2 - 2.2rem));
  width: 1px;
  background: color-mix(in srgb, var(--panel-edge) 60%, transparent);
  z-index: 40;
  pointer-events: none;
}
.light-spine i {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, var(--brass-dim), var(--brass));
  transform: scaleY(0);
  transform-origin: top;
  box-shadow: 0 0 8px color-mix(in srgb, var(--brass) 60%, transparent);
}
.light-spine i::after {
  content: "";
  position: absolute;
  bottom: -3px;
  left: -2.5px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brass);
  box-shadow: 0 0 10px var(--brass);
}
@media (max-width: 700px) { .light-spine { display: none; } }

/* hub link — back to the cave, fixed top left */
.hub-link {
  position: fixed;
  top: 1.1rem;
  left: 1.2rem;
  z-index: 60;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--brass);
  text-decoration: none;
  border: 1px solid var(--brass-dim);
  border-radius: 999px;
  padding: 0.45rem 0.95rem;
  background: color-mix(in srgb, var(--panel) 80%, transparent);
  backdrop-filter: blur(6px);
  transition: color 0.2s ease, border-color 0.2s ease, background 0.35s ease;
}
.hub-link svg { width: 15px; height: 15px; }
.hub-link:hover, .hub-link:focus-visible { color: var(--parchment); border-color: var(--brass); }

/* theme toggle — a small brass instrument, fixed top right */
.theme-toggle {
  position: fixed;
  top: 1.1rem;
  right: 1.2rem;
  z-index: 60;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--brass-dim);
  background: color-mix(in srgb, var(--panel) 80%, transparent);
  backdrop-filter: blur(6px);
  color: var(--brass);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.35s ease, border-color 0.35s ease, transform 0.2s ease;
}
.theme-toggle:hover { transform: rotate(15deg); }
.theme-toggle svg { width: 20px; height: 20px; }
.theme-toggle .sun { display: none; }
[data-theme="light"] .theme-toggle .sun { display: block; }
[data-theme="light"] .theme-toggle .moon { display: none; }

/* ═══ Hero ═══ */
.hero {
  position: relative;
  min-height: 94vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  text-align: center;
  background: radial-gradient(ellipse 120% 80% at 50% -20%, var(--hero-top) 0%, var(--obsidian) 65%);
  transition: background 0.35s ease;
}

.stars { position: absolute; inset: 0; pointer-events: none; }
.stars i {
  position: absolute;
  background: var(--star);
  border-radius: 50%;
  opacity: 0.5;
  animation: twinkle 4s ease-in-out infinite;
}
[data-theme="light"] .stars i { opacity: 0.18; animation: none; }
@keyframes twinkle {
  0%, 100% { opacity: 0.15; }
  50% { opacity: 0.7; }
}

.refraction {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.9;
  pointer-events: none;
}
.beam {
  stroke-dasharray: 1400;
  stroke-dashoffset: 1400;
  animation: draw 2.2s cubic-bezier(0.22, 1, 0.36, 1) forwards,
             shimmer 5s ease-in-out 2.4s infinite;
}
.beam-in { stroke: var(--beam-in); animation-delay: 0.3s, 2.4s; opacity: 0.9; }
.beam-out { opacity: 0.75; }
.b1 { animation-delay: 1.10s, 2.4s; }
.b2 { animation-delay: 1.22s, 2.9s; }
.b3 { animation-delay: 1.34s, 3.4s; }
.b4 { animation-delay: 1.46s, 3.9s; }
.b5 { animation-delay: 1.58s, 4.4s; }
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes shimmer {
  0%, 100% { opacity: 0.75; }
  50% { opacity: 0.4; }
}
[data-theme="light"] .b1 { stroke: #C1274B; }
[data-theme="light"] .b2 { stroke: #B4770F; }
[data-theme="light"] .b3 { stroke: #2E8B4A; }
[data-theme="light"] .b4 { stroke: #12857C; }
[data-theme="light"] .b5 { stroke: #6C55C8; }
[data-theme="light"] .beam-out { opacity: 0.85; }
.prism-shape { opacity: 0; animation: appear 1.2s ease 0.8s forwards; stroke: var(--brass); }
.chart { opacity: 0; animation: appear 2.4s ease 0.5s forwards; stroke: var(--brass); }
.chart .chart-dot { fill: var(--brass); }
@keyframes appear { to { opacity: 1; } }

.hero-content { position: relative; z-index: 2; padding: 3rem 1.5rem 16vh; }

.eyebrow {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.42em;
  text-transform: uppercase;
  color: var(--brass);
}

.title {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 300;
  font-size: clamp(4.2rem, 14vw, 8.5rem);
  letter-spacing: 0.18em;
  margin-left: 0.18em;
  line-height: 1.05;
  color: var(--parchment);
  text-shadow: 0 0 60px var(--title-glow);
}

.tagline {
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  font-weight: 400;
  font-size: clamp(1.25rem, 3vw, 1.7rem);
  color: var(--brass);
  margin-top: 0.4rem;
}

.lede {
  max-width: 34rem;
  margin: 1.4rem auto 2.2rem;
  color: var(--parchment-dim);
}

.badge { display: inline-block; transition: transform 0.25s ease, filter 0.25s ease; }
.badge:hover, .badge:focus-visible { transform: translateY(-2px); filter: brightness(1.15); }
.badge img { width: 200px; height: auto; }

.fineprint {
  margin-top: 1rem;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--parchment-dim);
}

.hero-fade {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 140px;
  background: linear-gradient(to bottom, transparent, var(--obsidian));
  pointer-events: none;
}

/* ═══ Shared section chrome ═══ */
main { max-width: 1060px; margin: 0 auto; padding: 0 1.5rem; }
section { padding: 4.5rem 0; }

.index-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  border-bottom: 1px solid var(--panel-edge);
  padding-bottom: 0.9rem;
  margin-bottom: 2.6rem;
}
.index-head h2 {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 400;
  font-size: clamp(1.8rem, 4.5vw, 2.4rem);
  letter-spacing: 0.06em;
  color: var(--parchment);
}
.index-count {
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  font-size: 1rem;
  color: var(--brass-dim);
  white-space: nowrap;
}

/* ═══ Entry I — the ledger ═══ */
.entry { padding: 5rem 0; }
.entry-rule {
  height: 1px;
  background: linear-gradient(to right, transparent, var(--brass-dim) 20%, var(--brass-dim) 80%, transparent);
  opacity: 0.5;
}
.entry-grid {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: 2.5rem;
  padding: 2.8rem 0;
  max-width: 52rem;
  margin: 0 auto;
}
.entry-margin {
  text-align: right;
  border-right: 1px solid var(--panel-edge);
  padding-right: 2.5rem;
}
.entry-no {
  display: block;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.4em;
  text-transform: uppercase;
  color: var(--brass);
}
.entry-numeral {
  display: block;
  font-family: 'Cormorant Garamond', serif;
  font-weight: 300;
  font-size: 4.4rem;
  line-height: 1;
  color: var(--brass);
  margin: 0.3rem 0 0.8rem;
}
.entry-note {
  display: block;
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  font-size: 0.95rem;
  line-height: 1.5;
  color: var(--parchment-dim);
}
.entry-body { max-width: 36rem; }
.story-text {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.3rem;
  line-height: 1.7;
  color: var(--parchment);
}
.story-text + .story-text { margin-top: 1.1rem; }
.story-text.emph { color: var(--brass); font-style: italic; }
.dropcap::first-letter {
  font-size: 3.6em;
  float: left;
  line-height: 0.82;
  padding: 0.06em 0.12em 0 0;
  color: var(--brass);
  font-style: normal;
}

/* ═══ Chamber — playable interlude ═══ */
.chamber-grid {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 3rem;
  align-items: center;
}
.chamber-copy h2 {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 400;
  font-size: clamp(1.8rem, 4.5vw, 2.4rem);
  letter-spacing: 0.06em;
  margin-bottom: 0.7rem;
}
.chamber-copy .section-note {
  color: var(--parchment-dim);
  max-width: 26rem;
}
.chamber-copy .hint {
  margin-top: 1.4rem;
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  color: var(--brass);
  font-size: 1.05rem;
}
.chamber-board {
  background: var(--board);
  border: 1px solid var(--panel-edge);
  border-radius: 10px;
  padding: 1.2rem 1.2rem 0.9rem;
  transition: background 0.35s ease;
}
.chamber-board svg { width: 100%; height: auto; display: block; }
.board-cell { fill: transparent; cursor: pointer; outline: none; }
.board-cell:focus-visible { outline: 2px solid var(--brass); outline-offset: -3px; }
.mirror-line {
  stroke: var(--parchment);
  stroke-width: 3.5;
  stroke-linecap: round;
  transition: transform 0.25s cubic-bezier(0.34, 1.4, 0.64, 1);
  pointer-events: none;
}
.mirror-pad {
  fill: color-mix(in srgb, var(--panel-edge) 55%, transparent);
  stroke: var(--panel-edge);
  rx: 8;
  pointer-events: none;
}
.grid-line { stroke: var(--panel-edge); stroke-width: 0.6; opacity: 0.6; }
.board-frame { stroke: var(--brass-dim); stroke-width: 1; fill: none; opacity: 0.7; }
.beam-path {
  stroke: #E5476B;
  stroke-width: 2.5;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
  filter: drop-shadow(0 0 5px rgba(229, 71, 107, 0.8));
  pointer-events: none;
}
.source-dot { fill: #E5476B; filter: drop-shadow(0 0 4px rgba(229, 71, 107, 0.9)); }
.target-ring { fill: none; stroke: var(--brass-dim); stroke-width: 1.6; stroke-dasharray: 2.5 3; }
.target-core { fill: var(--panel-edge); transition: fill 0.3s ease; }
.solved .target-ring { stroke: #E5476B; stroke-dasharray: none; }
.solved .target-core { fill: #E5476B; filter: drop-shadow(0 0 8px rgba(229, 71, 107, 0.9)); }
.solved .target-burst { animation: burst 0.9s ease forwards; }
.target-burst { opacity: 0; transform-box: fill-box; transform-origin: center; }
@keyframes burst {
  0% { opacity: 0.9; transform: scale(0.2); }
  100% { opacity: 0; transform: scale(1.6); }
}
.chamber-hud {
  display: flex;
  align-items: center;
  gap: 1.4rem;
  margin-top: 0.9rem;
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--parchment-dim);
}
.chamber-hud b { color: var(--parchment); font-weight: 600; }
.chamber-stars { color: var(--brass); font-size: 1rem; letter-spacing: 0.15em; min-width: 4.2rem; }
.chamber-reset {
  margin-left: auto;
  background: none;
  border: 1px solid var(--panel-edge);
  color: var(--parchment-dim);
  font: inherit;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.chamber-reset:hover, .chamber-reset:focus-visible { color: var(--brass); border-color: var(--brass-dim); }
.chamber-msg {
  margin-top: 0.7rem;
  min-height: 1.6rem;
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  color: var(--brass);
}

/* ═══ Index of Instruments ═══ */
.index-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 3.5rem;
}
.instrument {
  border-top: 1px solid var(--panel-edge);
  padding: 1.6rem 0 2rem;
}
.instrument header {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  margin-bottom: 0.7rem;
}
.inst-numeral {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.05rem;
  color: var(--brass-dim);
  min-width: 1.6rem;
  letter-spacing: 0.08em;
}
.glyph {
  width: 30px;
  height: 30px;
  color: var(--brass);
  flex-shrink: 0;
}
.instrument h3 {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 500;
  font-size: 1.45rem;
  letter-spacing: 0.03em;
  color: var(--parchment);
}
.instrument p {
  font-size: 0.92rem;
  color: var(--parchment-dim);
  padding-left: calc(1.6rem + 0.9rem);
}

/* ═══ Plates ═══ */
.plate-strip {
  display: flex;
  gap: 1.6rem;
  overflow-x: auto;
  padding: 0.5rem 0.25rem 1.4rem;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}
.plate-strip figure {
  flex: 0 0 auto;
  width: min(62vw, 250px);
  scroll-snap-align: center;
}
.plate-strip figure:nth-child(odd) { transform: rotate(-0.7deg); }
.plate-strip figure:nth-child(even) { transform: rotate(0.6deg); }
.plate-strip img {
  border: 1px solid var(--panel-edge);
  border-radius: 18px;
  box-shadow: 0 12px 40px var(--shot-shadow);
  transition: transform 0.35s cubic-bezier(0.22, 1, 0.36, 1), box-shadow 0.35s ease;
}
.plate-strip figure:hover img {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 22px 60px var(--shot-shadow);
}
.plate-strip figcaption {
  margin-top: 0.7rem;
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  font-size: 0.95rem;
  color: var(--parchment-dim);
  text-align: center;
}
.plate-strip figcaption span {
  font-style: normal;
  font-family: 'Inter', sans-serif;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--brass);
  display: block;
  margin-bottom: 0.15rem;
}
.plate-strip::-webkit-scrollbar { height: 6px; }
.plate-strip::-webkit-scrollbar-thumb { background: var(--panel-edge); border-radius: 3px; }
.plate-strip::-webkit-scrollbar-track { background: transparent; }

/* ═══ Seal / CTA ═══ */
.cta {
  position: relative;
  text-align: center;
  padding: 7rem 0 8rem;
}
.seal {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: min(340px, 82vw);
  pointer-events: none;
}
.seal circle { stroke: var(--brass); }
.cta-line {
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  color: var(--parchment);
  margin-bottom: 1.8rem;
}
.cta .badge { position: relative; }
.cta .badge img { width: 210px; }

/* ═══ Footer ═══ */
footer {
  border-top: 1px solid var(--panel-edge);
  text-align: center;
  padding: 2.8rem 1.5rem 3.2rem;
  font-size: 0.82rem;
  color: var(--parchment-dim);
}
.foot-motto {
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  font-size: 1.05rem;
  color: var(--brass-dim);
  margin-bottom: 0.5rem;
}
.foot-cookie {
  font-family: 'Cormorant Garamond', serif;
  font-style: italic;
  font-size: 0.95rem;
  color: var(--parchment-dim);
  margin-bottom: 1rem;
}
footer nav { margin-top: 0.5rem; display: flex; gap: 0.6rem; justify-content: center; }
footer a { color: var(--brass); text-decoration: none; }
footer a:hover, footer a:focus-visible { text-decoration: underline; }

/* reveals */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.shown { opacity: 1; transform: none; }

/* a11y */
a:focus-visible, button:focus-visible { outline: 2px solid var(--brass); outline-offset: 4px; }

.stars, .refraction, .hero-content { will-change: transform; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .light-spine { display: none; }
  .plate-strip figure { transform: none; }
  .plate-strip img { transition: none; }
  .beam { animation: none; stroke-dashoffset: 0; }
  .prism-shape, .chart { animation: none; opacity: 1; }
  .stars i { animation: none; opacity: 0.4; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .badge, .mirror-line, body, .hero { transition: none; }
  .solved .target-burst { animation: none; }
}

@media (max-width: 720px) {
  .index-grid { grid-template-columns: 1fr; }
  .chamber-grid { grid-template-columns: 1fr; gap: 2rem; }
}

@media (max-width: 560px) {
  .refraction { opacity: 0.55; }
  section { padding: 3.2rem 0; }
  .hero-content { padding-bottom: 22vh; }
  .entry-grid {
    grid-template-columns: 1fr;
    gap: 1.4rem;
  }
  .entry-margin {
    text-align: left;
    border-right: none;
    border-bottom: 1px solid var(--panel-edge);
    padding: 0 0 1.2rem;
  }
  .entry-numeral { display: inline; font-size: 2.4rem; margin: 0 0 0 0.6rem; vertical-align: -0.1em; }
  .entry-note { display: none; }
  .instrument p { padding-left: 0; }
}