:root {
  --bg-obsidian: #0e0d12;
  --bg-folio: #14131a;
  --bg-surface-hover: #1d1b24;
  --text-parchment: #f3ede2;
  --text-slate: #948e9b;
  --accent-gold: #c8a97e;
  --accent-ember: #b5656c;
  --border-hairline: rgba(243, 237, 226, 0.13);
  --border-gold: rgba(200, 169, 126, 0.55);

  --font-display: 'Cormorant Garamond', Georgia, serif;
  --font-body: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius-leaf: 3px;
}

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

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  background-color: var(--bg-obsidian);
  color: var(--text-parchment);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}

/* Base interactive cursor & focus discipline (R-32, R-39) */
a[href],
button:not(:disabled),
summary,
select,
label[for],
[role="button"]:not([aria-disabled="true"]) {
  cursor: pointer;
}

button:disabled,
[aria-disabled="true"] {
  cursor: not-allowed;
  opacity: 0.42;
}

:focus-visible {
  outline: 2px solid var(--accent-gold);
  outline-offset: 3px;
}

/* Three.js atmospheric background */
#atmosphere-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* Full-viewport paginated book shell */
.book-shell {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  height: 100dvh;
  width: 100%;
  max-width: 1220px;
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
  gap: 0.75rem;
}

/* Persistent Top Chrome */
.folio-chrome-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-shrink: 0;
  min-height: 44px;
}

.edition-mark {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 44px;
  padding: 0.35rem 0.65rem;
  margin-left: -0.65rem;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  transition: border-color 180ms ease, color 180ms ease;
}

.edition-mark:hover {
  color: var(--accent-gold);
  border-color: var(--border-hairline);
}

.seal-glyph {
  color: var(--accent-gold);
  flex-shrink: 0;
}

.chrome-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.chrome-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  min-height: 44px;
  padding: 0.45rem 0.85rem;
  background: rgba(20, 19, 26, 0.78);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: border-color 180ms ease, background-color 180ms ease, color 180ms ease;
}

.chrome-btn:hover {
  background: var(--bg-surface-hover);
  border-color: var(--border-gold);
  color: var(--accent-gold);
}

/* Main Book / Folio Stage */
.folio-stage {
  flex: 1;
  min-height: 0;
  display: flex;
  background: var(--bg-folio);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  box-shadow: 0 22px 60px rgba(0, 0, 0, 0.55);
  overflow: hidden;
  position: relative;
}

.spread-viewport {
  flex: 1;
  min-height: 0;
  width: 100%;
  display: flex;
}

.spread {
  flex: 1;
  min-height: 0;
  width: 100%;
  overflow-y: auto;
  overflow-x: hidden;
  padding: clamp(1.5rem, 3.2vw, 3rem) clamp(1.25rem, 4vw, 3.5rem);
  display: flex;
  flex-direction: column;
  scrollbar-width: thin;
  scrollbar-color: rgba(200, 169, 126, 0.3) transparent;
}

/* Page-turn transitions (MOTION 2, reduced-motion safe) */
@media (prefers-reduced-motion: no-preference) {
  .spread-viewport[data-turn="forward"] .spread {
    animation: turnForward 280ms cubic-bezier(0.22, 1, 0.36, 1) both;
  }

  .spread-viewport[data-turn="backward"] .spread {
    animation: turnBackward 280ms cubic-bezier(0.22, 1, 0.36, 1) both;
  }
}

@keyframes turnForward {
  from {
    opacity: 0;
    transform: translateX(24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes turnBackward {
  from {
    opacity: 0;
    transform: translateX(-24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Typography helpers */
.mono-label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-slate);
}

.mono-accent {
  color: var(--accent-gold);
}

/* Spread 00: Cover */
.spread-cover {
  justify-content: center;
  align-items: center;
  text-align: center;
}

.cover-inner {
  max-width: 60ch;
  margin: auto 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.15rem;
}

.cover-seal {
  color: var(--accent-gold);
  margin-bottom: 0.25rem;
}

.cover-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2.25rem, 4.5vw, 3.75rem);
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--text-parchment);
}

.cover-subtitle {
  margin: 0;
  max-width: 48ch;
  font-size: clamp(0.98rem, 1.1vw, 1.08rem);
  color: var(--text-slate);
}

.cover-dedication {
  margin-top: 0.5rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--border-hairline);
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.25rem;
  color: var(--text-parchment);
}

.cover-from {
  font-size: 1rem;
  color: var(--text-slate);
}

.primary-cta {
  margin-top: 0.65rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  min-height: 46px;
  padding: 0.75rem 1.75rem;
  background: var(--accent-gold);
  color: var(--bg-folio);
  border: 1px solid var(--accent-gold);
  border-radius: var(--radius-leaf);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  transition: background-color 180ms ease, color 180ms ease, transform 160ms ease;
}

.primary-cta:hover {
  background: var(--text-parchment);
  border-color: var(--text-parchment);
}

.primary-cta:active {
  transform: translateY(1px);
}

/* Two-Column Book Spread (Greeting & Questions) */
.spread-folio {
  justify-content: center;
}

.folio-grid {
  width: 100%;
  margin: auto 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
}

@media (min-width: 860px) {
  .folio-grid {
    grid-template-columns: 1fr 1.15fr;
    gap: 0;
    align-items: start;
  }

  .folio-col-left {
    padding-right: clamp(1.75rem, 3.2vw, 3rem);
    border-right: 1px solid var(--border-hairline);
  }

  .folio-col-right {
    padding-left: clamp(1.75rem, 3.2vw, 3rem);
  }
}

.spread-heading {
  margin: 0.45rem 0 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.65rem, 2.8vw, 2.35rem);
  line-height: 1.18;
  color: var(--text-parchment);
}

.spread-theme {
  margin: 0.4rem 0 0;
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.12rem;
  color: var(--text-slate);
}

.plate-note {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-hairline);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.plate-caption {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-slate);
}

.prose-stack {
  display: flex;
  flex-direction: column;
  gap: 1.05rem;
  max-width: 58ch;
}

.prose-stack p {
  margin: 0;
  font-size: clamp(0.98rem, 1.05vw, 1.06rem);
  line-height: 1.72;
  color: var(--text-parchment);
}

.inline-action-wrap {
  margin-top: 1.5rem;
}

/* Question Prompt & Choices */
.question-prompt {
  margin: 1.25rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 1.65vw, 1.42rem);
  line-height: 1.55;
  color: var(--text-parchment);
  max-width: 48ch;
  min-height: 4.5rem;
}

.reveal-btn {
  margin-top: 0.9rem;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0.35rem 0.85rem;
  background: transparent;
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  color: var(--text-slate);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: color 160ms ease, border-color 160ms ease;
}

.reveal-btn:hover {
  color: var(--accent-gold);
  border-color: var(--border-gold);
}

.reveal-btn[hidden] {
  display: none;
}

.choices-hint {
  margin: 0 0 0.9rem;
  font-size: 0.88rem;
  color: var(--text-slate);
}

.choices-list {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.choice-btn {
  width: 100%;
  min-height: 48px;
  padding: 0.85rem 1rem;
  text-align: left;
  background: rgba(14, 13, 18, 0.55);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.5;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  transition: background-color 180ms ease, border-color 180ms ease;
}

.choice-btn:hover {
  background: var(--bg-surface-hover);
  border-color: var(--border-gold);
}

.choice-btn[aria-pressed="true"] {
  background: var(--bg-surface-hover);
  border-color: var(--accent-gold);
}

.choice-index {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-gold);
  padding-top: 0.15rem;
  flex-shrink: 0;
}

.response-card {
  margin-top: 1.15rem;
  padding: 1rem 1.15rem;
  background: rgba(14, 13, 18, 0.72);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-leaf);
}

.response-prefix {
  margin: 0 0 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-gold);
}

.response-text {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--text-parchment);
}

.next-invite {
  margin-top: 1rem;
  display: flex;
  justify-content: flex-end;
}

.secondary-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.5rem 1.1rem;
  background: transparent;
  border: 1px solid var(--accent-gold);
  border-radius: var(--radius-leaf);
  color: var(--accent-gold);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: background-color 160ms ease, color 160ms ease;
}

.secondary-cta:hover {
  background: var(--accent-gold);
  color: var(--bg-folio);
}

/* Spread 08: Memory Plates */
.gallery-header {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-bottom: 1.25rem;
}

.gallery-subtitle {
  margin: 0;
  max-width: 60ch;
  font-size: 0.94rem;
  color: var(--text-slate);
}

.gallery-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
}

@media (min-width: 640px) {
  .gallery-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .gallery-grid {
    grid-template-columns: repeat(12, 1fr);
    gap: 1rem;
  }

  .plate-card[data-plate-index="0"] {
    grid-column: span 5;
  }

  .plate-card[data-plate-index="1"] {
    grid-column: span 3;
  }

  .plate-card[data-plate-index="2"] {
    grid-column: span 4;
  }

  .plate-card[data-plate-index="3"] {
    grid-column: span 7;
  }

  .plate-card[data-plate-index="4"] {
    grid-column: span 5;
  }
}

.plate-card {
  width: 100%;
  padding: 0.7rem;
  background: rgba(14, 13, 18, 0.55);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  transition: border-color 180ms ease, background-color 180ms ease;
}

.plate-card:hover {
  background: var(--bg-surface-hover);
  border-color: var(--border-gold);
}

.plate-frame {
  width: 100%;
  aspect-ratio: 16 / 10;
  background: var(--bg-obsidian);
  border: 1px solid var(--border-hairline);
  border-radius: 2px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.plate-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.plate-empty {
  padding: 0.85rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
}

.plate-empty-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--accent-gold);
}

.plate-empty-hint {
  font-size: 0.78rem;
  color: var(--text-slate);
  max-width: 28ch;
}

.plate-meta {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
}

.plate-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text-parchment);
}

/* Spread 09: Final Letter & Seal */
.spread-letter {
  align-items: center;
}

.letter-sheet {
  width: 100%;
  max-width: 58ch;
  margin: auto 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.letter-salutation {
  margin: 0.4rem 0 0;
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.35rem;
  color: var(--text-parchment);
}

.letter-body {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.letter-body p {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.72;
  color: var(--text-parchment);
}

.letter-signoff {
  margin-top: 0.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.letter-closing {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-slate);
}

.letter-signature {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: var(--text-parchment);
}

.seal-box {
  margin-top: 0.75rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-hairline);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.seal-action-group {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.seal-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  min-height: 46px;
  padding: 0.6rem 1.25rem;
  background: transparent;
  border: 1px solid var(--accent-gold);
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: border-color 200ms ease, background-color 200ms ease;
}

.seal-btn:hover {
  background: var(--bg-surface-hover);
}

.seal-btn[aria-pressed="true"] {
  border-color: var(--accent-ember);
  background: rgba(181, 101, 108, 0.14);
}

.seal-btn[aria-pressed="true"] .seal-svg {
  color: var(--accent-ember);
}

.seal-svg {
  color: var(--accent-gold);
  transition: color 200ms ease;
}

.seal-confirmation {
  margin: 0.35rem 0 0;
  font-size: 0.9rem;
  color: var(--text-parchment);
}

/* Persistent Bottom Chrome */
.folio-chrome-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-shrink: 0;
  min-height: 46px;
}

.turn-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-height: 44px;
  min-width: 112px;
  padding: 0.5rem 1rem;
  background: rgba(20, 19, 26, 0.78);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: border-color 180ms ease, background-color 180ms ease, color 180ms ease;
}

.turn-btn:hover:not(:disabled) {
  background: var(--bg-surface-hover);
  border-color: var(--border-gold);
  color: var(--accent-gold);
}

.turn-btn-primary:not(:disabled) {
  border-color: var(--border-gold);
}

.folio-progress {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  min-width: 96px;
}

.folio-counter {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--text-slate);
}

.folio-track {
  width: 84px;
  height: 2px;
  background: var(--border-hairline);
  overflow: hidden;
}

.folio-track-fill {
  height: 100%;
  width: 10%;
  background: var(--accent-gold);
  transition: width 260ms ease;
}

/* Dialogs: Contents & Lightbox */
dialog {
  padding: 0;
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  background: var(--bg-folio);
  color: var(--text-parchment);
  max-width: min(92vw, 560px);
  width: 100%;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.75);
}

dialog::backdrop {
  background: rgba(8, 7, 11, 0.78);
}

.plate-lightbox {
  max-width: min(92vw, 760px);
}

.contents-panel,
.lightbox-panel {
  padding: 1.35rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.contents-header,
.lightbox-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
}

.contents-title,
.lightbox-title {
  margin: 0.2rem 0 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.6rem;
  color: var(--text-parchment);
}

.icon-close-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  background: transparent;
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
}

.icon-close-btn:hover {
  border-color: var(--border-gold);
  color: var(--accent-gold);
}

.contents-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  max-height: 60dvh;
  overflow-y: auto;
}

.contents-item-btn {
  width: 100%;
  min-height: 44px;
  padding: 0.6rem 0.85rem;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-leaf);
  color: var(--text-parchment);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  text-align: left;
  transition: background-color 160ms ease, border-color 160ms ease;
}

.contents-item-btn:hover {
  background: var(--bg-surface-hover);
  border-color: var(--border-hairline);
}

.contents-item-btn[aria-current="page"] {
  background: var(--bg-surface-hover);
  border-color: var(--accent-gold);
}

.contents-item-left {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
}

.contents-item-title {
  font-size: 0.95rem;
}

.contents-status {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--accent-gold);
}

.lightbox-media {
  width: 100%;
  aspect-ratio: 16 / 10;
  background: var(--bg-obsidian);
  border: 1px solid var(--border-hairline);
  border-radius: 2px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lightbox-media img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.lightbox-meta {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.lightbox-sub {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-slate);
}

.lightbox-caption {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-parchment);
}

/* Mobile refinements (375px+) */
@media (max-width: 639px) {
  .book-shell {
    padding: 0.65rem 0.75rem;
    gap: 0.55rem;
  }

  .turn-btn {
    min-width: 96px;
    padding: 0.5rem 0.7rem;
    font-size: 0.7rem;
  }

  .folio-track {
    width: 64px;
  }
}