/* ==========================================================================
   Visual Novel — "deep night cinema" theme (pure CSS, no JS)
   Palette: deep blue-black base, moonlit blue accents, soft glows.
   All classes below follow the engine DOM contract; see the deviation
   notes in the comment block at the end of this file.

   Cinematic layer additions (v2):
   - .vn-vignette / .vn-grain   fullscreen overlay layers (engine adds the
     elements; CSS styles them wherever they are inserted)
   - .vn-bg.vn-fading           background dip-to-black toggle (~650ms)
   - .vn-text.vn-glitch         1.2s one-shot RGB-split glitch
   - #vn-app.vn-shake           500ms camera shake
   - .vn-dialog.vn-enter        dialog subtitle-bar entry animation
   - art.js busts breathe via .vn-sprite > svg (inert until art is wired)

   Stage additions (v3) — classic VN layout:
   - .vn-sprites                full-width stage strip above the dialog;
     .vn-sprite is a large free-standing portrait anchored bottom
   - .vn-pos-left / .vn-pos-right / .vn-solo   slot positions (slot 0 left,
     slot 1 right; solo drifts toward center)
   - .vn-enter / .vn-leave      slide-up entrance / slide-down exit (engine
     removes the classes/elements; re-entry inside the leave window reuses
     the element)
   - .vn-swap                   quick crossfade pulse over a feel-art swap
   - .vn-name::before           1px colored left-notch on the name plate
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design tokens
   -------------------------------------------------------------------------- */
:root {
  --vn-bg: #04070f;
  --vn-bg-raise: #0a1120;
  --vn-panel: rgba(10, 16, 30, 0.78);
  --vn-panel-deep: rgba(6, 10, 20, 0.92);
  --vn-border: rgba(255, 255, 255, 0.12);
  --vn-border-soft: rgba(255, 255, 255, 0.08);
  --vn-text: #e9f0fb;
  --vn-text-dim: rgba(212, 224, 244, 0.62);
  --vn-text-faint: rgba(196, 210, 234, 0.45);
  --vn-accent: #8fb8ff;
  --vn-accent-soft: rgba(143, 184, 255, 0.5);
  --vn-accent-glow: rgba(110, 160, 255, 0.32);
  --vn-warm: rgba(255, 124, 92, 0.38);
  --vn-font:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC",
    "Source Han Sans SC", sans-serif;
  --vn-font-title:
    Georgia, "Times New Roman", "Songti SC", "STSong", "Noto Serif CJK SC",
    "SimSun", serif;
}

/* --------------------------------------------------------------------------
   2. Base / app root
   -------------------------------------------------------------------------- */
html,
body {
  margin: 0;
  padding: 0;
  background: var(--vn-bg);
}

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

#vn-app {
  /* palette lives here too, so overrides can be scoped per app */
  --vn-sprite-lift: 190px; /* sprite stage bottom above the viewport bottom
                              (dialog bar + margin + headroom for the pool) */

  position: fixed;
  inset: 0;
  overflow: hidden;
  min-width: 320px;
  background: var(--vn-bg);
  color: var(--vn-text);
  font-family: var(--vn-font);
  font-size: 16px;
  line-height: 1.6;
  color-scheme: dark;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  user-select: none;
  -webkit-user-select: none;
  cursor: default;
}

#vn-app ::selection {
  background: rgba(130, 175, 255, 0.3);
}

/* button reset — components below re-add chrome */
#vn-app button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  padding: 0;
  margin: 0;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

#vn-app button:focus-visible {
  outline: 2px solid var(--vn-accent);
  outline-offset: 2px;
}

/* engine-owned hidden state */
.vn-hidden {
  display: none !important;
}

/* --------------------------------------------------------------------------
   3. Background layer
   -------------------------------------------------------------------------- */
.vn-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  /* opacity fade-back uses the longer base curve; the dip-to-black in
     .vn-fading below tightens both curves to .3s while the class is on;
     transform easing serves the .vn-dolly push-in (compositor-only) */
  transition:
    opacity 0.6s ease,
    filter 0.3s ease,
    transform 1.2s cubic-bezier(0.22, 0.61, 0.36, 1);
  /* best-effort framing if the engine sets backgroundImage only */
  background-size: cover;
  background-position: center;
}

/* fx layer inside .vn-bg: hosts animated css dioramas (innerHTML) and the
   canvas scene renderer; must fill .vn-bg so canvas sizing reads real dims */
.vn-bg-fx {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
}

.vn-bg-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

/* cinematic letterbox scrim: darker top edge + fade into the dialog zone */
.vn-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(2, 4, 9, 0.5) 0%,
    rgba(2, 4, 9, 0) 20%,
    rgba(2, 4, 9, 0) 58%,
    rgba(2, 4, 9, 0.72) 100%
  );
}

/* dip-to-black toggle (engine flips the class ~650ms on scene change):
   bright to black in .3s; removing the class returns via the base .6s curve */
.vn-bg.vn-fading {
  filter: brightness(0);
  opacity: 0.3;
  transition:
    opacity 0.3s ease,
    filter 0.3s ease;
}

/* dolly zoom (fx:"dolly" line): camera pushes toward the emotional subject —
   the background scales up around the upper-third origin and softens (a
   single blur step per line, never an animated radius), while the focus
   sprite leans in via its own transform transition below */
#vn-app.vn-dolly .vn-bg {
  transform: scale(1.06);
  transform-origin: 50% 30%;
  filter: blur(2px) brightness(0.92);
}

#vn-app.vn-dolly .vn-sprite.vn-focus {
  transform: scale(1.15) translateY(-4px);
}

/* scene color grade (fx:"grade"): cools and deepens the frame — a mood
   shift without changing scenes; cleared on advance like glitch/dolly */
#vn-app.vn-grade .vn-bg {
  filter: saturate(0.72) contrast(1.06) brightness(0.88) hue-rotate(-6deg);
}

#vn-app.vn-grade .vn-grain {
  opacity: 0.09; /* grain reads heavier under the cooler grade */
}

/* --------------------------------------------------------------------------
   4. Sprite stage (large waist-up portraits, left + right of the dialog)
   -------------------------------------------------------------------------- */
.vn-sprites {
  position: absolute;
  left: 0;
  right: 0;
  bottom: var(--vn-sprite-lift); /* safe stage lift above the dialog bar */
  z-index: 1;
  height: 52vh;
  pointer-events: none;
}

/* Large waist-up portrait standing free on the stage (no card/clip), anchored
   to the strip's bottom edge. --vn-color survives only as the light-pool
   ::after beneath the character. The engine drives .vn-pos-left/right,
   .vn-solo, .vn-enter/.vn-leave/.vn-swap, .vn-focus/.vn-dim. */
.vn-sprite {
  position: absolute;
  bottom: 0;
  width: clamp(200px, 26vw, 340px);
  height: auto;
  border-radius: 0;
  display: flex;
  align-items: flex-end; /* initial-letter fallback sits on the stage floor */
  justify-content: center;
  font-size: 44px; /* text-initial fallback while art.js is not wired */
  font-weight: 600;
  color: rgba(240, 246, 255, 0.95);
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.6);
  filter: drop-shadow(0 18px 24px rgba(0, 0, 0, 0.45));
  transition:
    transform 0.45s cubic-bezier(0.22, 0.61, 0.36, 1),
    opacity 0.45s ease,
    filter 0.45s ease;
}

/* stage light pool: a soft ellipse of the character color under the feet */
.vn-sprite::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -16px;
  width: 76%;
  height: 30px;
  transform: translateX(-50%);
  border-radius: 50%;
  pointer-events: none;
  z-index: -1;
  background: radial-gradient(
    closest-side,
    rgba(143, 184, 255, 0.4),
    rgba(143, 184, 255, 0) 74%
  );
  background: radial-gradient(
    closest-side,
    color-mix(in srgb, var(--vn-color, #8fb8ff) 42%, transparent),
    transparent 76%
  );
  filter: blur(3px);
  opacity: 0.5;
  transition: opacity 0.45s ease;
}

/* art.js waist-up portrait fills the sprite; anchored bottom, gently
   breathing. The .3s fade-in re-runs whenever the engine swaps the innerHTML,
   acting as the crossfade ease. Inert while the engine prints text. */
.vn-sprite > svg {
  display: block;
  width: 100%;
  height: auto;
  transform-origin: 50% 100%;
  animation:
    vn-sprite-breathe 4s ease-in-out infinite alternate,
    vn-sprite-in 0.3s ease-out;
}

/* --- stage positions (engine assigns by slot; solo nudge) ---------------- */
.vn-pos-left {
  left: 6vw;
  --vn-enter-dx: -70px; /* slides in from (and exits toward) the left edge */
}

.vn-pos-right {
  right: 6vw;
  --vn-enter-dx: 70px;
}

.vn-solo {
  left: 18vw; /* lone character drifts toward center; right stays auto */
  right: auto;
}

/* --- mood variants (data-feel) ------------------------------------------ */
.vn-sprite[data-feel="happy"] {
  transform: scale(1.05);
}

/* sad keeps the base drop-shadow inside its filter chain (one filter property) */
.vn-sprite[data-feel="sad"] {
  filter: grayscale(0.75) brightness(0.85)
    drop-shadow(0 18px 24px rgba(0, 0, 0, 0.45));
  transform: translateY(5px);
}

.vn-sprite[data-feel="sad"]::after {
  opacity: 0.2; /* the light pool dims with the mood */
}

.vn-sprite[data-feel="surprised"] {
  transform: scale(1.09);
}

/* angry: warm rim via an extra tinted drop-shadow (no box to glow around) */
.vn-sprite[data-feel="angry"] {
  filter: drop-shadow(0 18px 24px rgba(0, 0, 0, 0.45))
    drop-shadow(0 0 24px var(--vn-warm));
}

/* --- focus / dim states (declared after moods: focus transform wins) ----- */
.vn-sprite.vn-focus {
  opacity: 1;
  transform: translateY(-8px) scale(1.02);
}

.vn-sprite.vn-focus::after {
  opacity: 0.95; /* light pool brightens under the speaker */
}

.vn-sprite.vn-dim {
  opacity: 0.55;
  filter: saturate(0.85) drop-shadow(0 18px 24px rgba(0, 0, 0, 0.45));
}

/* dim + sad compose instead of clobbering (single filter property) */
.vn-sprite[data-feel="sad"].vn-dim {
  filter: grayscale(0.75) brightness(0.85) saturate(0.85)
    drop-shadow(0 18px 24px rgba(0, 0, 0, 0.45));
}

/* --- entrance / exit / feel-swap (engine-toggled, self-cleaning) --------- */
.vn-sprite.vn-enter {
  animation: vn-sprite-rise 0.45s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.vn-sprite.vn-leave {
  animation: vn-sprite-drop 0.35s ease-in forwards;
  pointer-events: none;
}

/* quick crossfade/scale pulse around a feel-art innerHTML swap; the full
   animation list is restated so the pulse composes with breathe + in */
.vn-sprite.vn-swap > svg {
  animation:
    vn-sprite-breathe 4s ease-in-out infinite alternate,
    vn-sprite-in 0.3s ease-out,
    vn-swap-pulse 0.18s ease-out;
}

/* --------------------------------------------------------------------------
   5. Dialog box (cinematic subtitle bar)
   -------------------------------------------------------------------------- */
.vn-dialog {
  position: absolute;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  z-index: 2;
  width: min(92%, 860px);
  max-width: 860px;
  margin-bottom: 24px;
  padding: 18px 24px;
  /* gradient glass: two stacked rgba layers + blur/saturate behind */
  background:
    linear-gradient(180deg, rgba(18, 27, 48, 0.85) 0%, rgba(9, 14, 27, 0.8) 100%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.045) 0%, rgba(255, 255, 255, 0) 42%);
  border: 1px solid var(--vn-border);
  border-top-color: rgba(255, 255, 255, 0.2); /* 1px top highlight edge */
  border-radius: 14px;
  backdrop-filter: blur(16px) saturate(1.35);
  -webkit-backdrop-filter: blur(16px) saturate(1.35);
  box-shadow:
    0 -6px 30px rgba(0, 0, 0, 0.35),
    inset 0 1px 0 rgba(255, 255, 255, 0.07);
}

/* inner top-left corner accent line, drawn in currentColor: when the engine
   (or a theme) sets color on .vn-dialog it picks up the character color;
   otherwise it rests on the base text tone. */
.vn-dialog::before {
  content: "";
  position: absolute;
  top: 9px;
  left: 11px;
  width: 26px;
  height: 2px;
  border-radius: 1px;
  background: linear-gradient(90deg, currentColor, transparent);
  opacity: 0.75;
  pointer-events: none;
}

/* entry animation hook (engine may not add .vn-enter yet; CSS is ready).
   The keyframes carry the translateX(-50%) centering so it survives. */
.vn-dialog.vn-enter {
  animation: vn-dialog-in 0.35s ease-out both;
}

.vn-name {
  position: absolute;
  top: 0;
  left: 22px;
  transform: translateY(-50%);
  padding: 4px 20px 4px 13px;
  /* angular plate with a clipped notch corner (top-right bevel) */
  clip-path: polygon(0 0, calc(100% - 11px) 0, 100% 11px, 100% 100%, 0 100%);
  background: linear-gradient(135deg, #141e36 0%, #0a1120 100%);
  border: 1px solid var(--vn-accent-soft);
  color: var(--vn-accent);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.1em;
  white-space: nowrap;
  /* clip-path cuts box-shadow, so the lift + subtle glow ride on filter */
  filter:
    drop-shadow(0 3px 8px rgba(0, 0, 0, 0.45))
    drop-shadow(0 0 7px rgba(120, 165, 255, 0.16));
}

/* 1px colored left-notch: a hairline spine in the speaker color, matching the
   plate's angular language (the dialog's own ::before corner accent echoes it) */
.vn-name::before {
  content: "";
  position: absolute;
  left: 0;
  top: 3px;
  bottom: 3px;
  width: 1px;
  background: currentColor;
  opacity: 0.85;
  pointer-events: none;
}

/* dim the name-plate border against the engine-set character color */
@supports (border-color: color-mix(in srgb, currentColor 55%, transparent)) {
  .vn-name {
    border-color: color-mix(in srgb, currentColor 55%, transparent);
  }

  .vn-name {
    filter:
      drop-shadow(0 3px 8px rgba(0, 0, 0, 0.45))
      drop-shadow(0 0 8px color-mix(in srgb, currentColor 30%, transparent));
  }
}

.vn-text {
  font-size: 16.5px;
  line-height: 1.8;
  min-height: 3.6em;
  color: var(--vn-text);
  letter-spacing: 0.01em;
  white-space: pre-wrap;
  word-break: break-word;
}

/* narration mode: italic-ish, muted, nameless */
.vn-dialog.vn-narr {
  background:
    linear-gradient(180deg, rgba(10, 15, 28, 0.72) 0%, rgba(6, 10, 20, 0.62) 100%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.03) 0%, rgba(255, 255, 255, 0) 42%);
}

.vn-dialog.vn-narr .vn-text {
  color: var(--vn-text-dim);
  font-style: italic;
}

.vn-dialog.vn-narr .vn-name {
  display: none;
}

.vn-dialog.vn-narr::before {
  opacity: 0.3;
}

/* screen-reader live channel: full dialogue lines land here once per
   display; visually hidden so it never disturbs the typewriter view */
.vn-sr-live {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* decorative auto-mode progress line along the dialog's bottom edge; the
   engine sets animation-duration inline (mirrors the auto-advance delay) */
.vn-auto-bar {
  position: absolute;
  left: 18px;
  right: 18px;
  bottom: 6px;
  height: 3px;
  border-radius: 2px;
  overflow: hidden;
  pointer-events: none;
  background: rgba(255, 255, 255, 0.06);
}

.vn-auto-bar i {
  display: block;
  width: 0;
  height: 100%;
  border-radius: 2px;
  background: var(--vn-accent, rgba(150, 190, 255, 0.75));
  opacity: 0.85;
}

.vn-auto-bar i.vn-auto-run {
  animation: vn-auto-fill linear forwards;
}

@keyframes vn-auto-fill {
  from {
    width: 0;
  }
  to {
    width: 100%;
  }
}

/* --------------------------------------------------------------------------
   6. Choices overlay
   -------------------------------------------------------------------------- */
.vn-choices {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 24px 16px;
  /* container is invisible; only the buttons take clicks */
  pointer-events: none;
}

button.vn-choice {
  pointer-events: auto;
  min-width: 260px;
  max-width: 100%;
  padding: 12px 30px;
  border-radius: 999px;
  background: rgba(13, 20, 38, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #dde8f9;
  font-size: 15px;
  letter-spacing: 0.04em;
  text-align: center;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
  /* staggered entrance: delays via nth-child below; `backwards` keeps the
     button hidden during its delay window */
  animation: vn-choice-in 0.38s ease-out backwards;
  transition:
    border-color 0.25s ease,
    box-shadow 0.25s ease,
    background 0.25s ease,
    color 0.25s ease,
    transform 0.2s ease;
}

.vn-choices button.vn-choice:nth-child(1) { animation-delay: 0.05s; }
.vn-choices button.vn-choice:nth-child(2) { animation-delay: 0.13s; }
.vn-choices button.vn-choice:nth-child(3) { animation-delay: 0.21s; }
.vn-choices button.vn-choice:nth-child(4) { animation-delay: 0.29s; }
.vn-choices button.vn-choice:nth-child(5) { animation-delay: 0.37s; }

button.vn-choice:hover {
  background: rgba(22, 33, 60, 0.82);
  border-color: rgba(150, 190, 255, 0.7);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow:
    0 0 0 1px rgba(150, 190, 255, 0.25),
    0 0 26px var(--vn-accent-glow),
    0 10px 26px rgba(0, 0, 0, 0.38);
}

button.vn-choice:active {
  transform: translateY(0) scale(0.97);
}

/* --------------------------------------------------------------------------
   7. Top bar buttons (glass chips)
   -------------------------------------------------------------------------- */
.vn-topbar {
  position: absolute;
  top: 14px;
  right: 14px;
  z-index: 4;
  display: flex;
  gap: 8px;
}

button.vn-btn {
  height: 32px;
  padding: 0 15px;
  border-radius: 999px;
  background: linear-gradient(180deg, rgba(20, 29, 50, 0.6) 0%, rgba(10, 16, 30, 0.55) 100%);
  border: 1px solid rgba(255, 255, 255, 0.14);
  color: rgba(222, 232, 250, 0.8);
  font-size: 12px;
  letter-spacing: 0.06em;
  white-space: nowrap;
  backdrop-filter: blur(10px) saturate(1.2);
  -webkit-backdrop-filter: blur(10px) saturate(1.2);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06);
  transition:
    background 0.25s ease,
    border-color 0.25s ease,
    color 0.25s ease,
    box-shadow 0.25s ease;
}

button.vn-btn:hover {
  background: rgba(24, 34, 58, 0.75);
  border-color: rgba(150, 190, 255, 0.45);
  color: #ffffff;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    0 0 14px var(--vn-accent-glow);
}

button.vn-btn.vn-active {
  background: rgba(22, 34, 62, 0.8);
  border-color: var(--vn-accent-soft);
  color: #ffffff;
  box-shadow:
    0 0 12px var(--vn-accent-glow),
    inset 0 0 8px rgba(130, 175, 255, 0.1);
}

/* --------------------------------------------------------------------------
   8. Backlog overlay (fullscreen dim + centered scrollable card)
   -------------------------------------------------------------------------- */
.vn-backlog {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 5;
  width: min(90%, 640px);
  max-height: 70vh;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 20px 24px;
  background: var(--vn-panel-deep);
  border: 1px solid var(--vn-border);
  border-radius: 16px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  /* the "fullscreen rgba backdrop": shadow spreads the dim across the screen */
  box-shadow:
    0 0 0 100vmax rgba(3, 6, 12, 0.68),
    0 30px 70px rgba(0, 0, 0, 0.55);
  user-select: text;
  -webkit-user-select: text;
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.15) transparent;
}

.vn-backlog::-webkit-scrollbar {
  width: 8px;
}

.vn-backlog::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.12);
  border-radius: 4px;
}

.vn-backlog::-webkit-scrollbar-track {
  background: transparent;
}

.vn-backlog-line {
  margin: 0 0 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 14px;
  line-height: 1.7;
}

.vn-backlog-line:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

b.vn-backlog-name {
  color: var(--vn-accent); /* engine may override per character */
  font-weight: 600;
  margin-right: 8px;
}

span.vn-backlog-text {
  color: var(--vn-text-dim);
}

/* --------------------------------------------------------------------------
   9. Menu overlay (fullscreen dim + centered card: save/load slots)
   -------------------------------------------------------------------------- */
.vn-menu {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 6;
  width: min(90%, 420px);
  max-height: 80vh;
  overflow-y: auto;
  padding: 26px 24px;
  background: var(--vn-panel-deep);
  border: 1px solid var(--vn-border);
  border-radius: 18px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow:
    0 0 0 100vmax rgba(3, 6, 12, 0.72),
    0 30px 70px rgba(0, 0, 0, 0.55);
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.15) transparent;
}

.vn-menu-title {
  margin: 0 0 18px;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.3em;
  text-indent: 0.3em;
  text-align: center;
  color: var(--vn-text);
  text-shadow: 0 0 16px rgba(130, 170, 255, 0.25);
}

button.vn-slot {
  display: block;
  width: 100%;
  text-align: left;
  padding: 14px;
  margin-bottom: 10px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.045);
  border: 1px solid var(--vn-border-soft);
  color: var(--vn-text);
  font-size: 14px;
  transition:
    border-color 0.25s ease,
    background 0.25s ease,
    box-shadow 0.25s ease;
}

button.vn-slot:hover {
  background: rgba(255, 255, 255, 0.07);
  border-color: var(--vn-accent-soft);
  box-shadow: 0 0 16px rgba(110, 160, 255, 0.18);
}

button.vn-slot:last-of-type {
  margin-bottom: 0;
}

.vn-slot-info {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--vn-text-faint);
}

/* Save-slot scene thumbnail (load mode only): fixed 16:9 box, cover-cropped.
   Slot rows grow naturally; 96px still fits the 320px .vn-menu (92% + padding). */
.vn-slot-thumb {
  display: block;
  width: 96px;
  height: 54px;
  object-fit: cover;
  border-radius: 6px;
  border: 1px solid var(--vn-border);
  margin-bottom: 6px;
}

button.vn-close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  line-height: 1;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--vn-border);
  color: var(--vn-text-dim);
  transition:
    color 0.25s ease,
    border-color 0.25s ease,
    background 0.25s ease;
}

button.vn-close:hover {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.12);
}

/* --------------------------------------------------------------------------
   9b. Settings overlay (same card language as .vn-menu: volume + auto delay)
   -------------------------------------------------------------------------- */
.vn-settings {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 6;
  width: min(90%, 420px);
  padding: 26px 24px;
  background: var(--vn-panel-deep);
  border: 1px solid var(--vn-border);
  border-radius: 18px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow:
    0 0 0 100vmax rgba(3, 6, 12, 0.72),
    0 30px 70px rgba(0, 0, 0, 0.55);
}

.vn-settings-title {
  margin: 0 0 18px;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.3em;
  text-indent: 0.3em;
  text-align: center;
  color: var(--vn-text);
  text-shadow: 0 0 16px rgba(130, 170, 255, 0.25);
}

.vn-setting-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px;
  margin-bottom: 10px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.045);
  border: 1px solid var(--vn-border-soft);
}

.vn-setting-row:last-of-type {
  margin-bottom: 0;
}

.vn-setting-row label {
  flex: 0 0 4.5em; /* fixed width: 自动推进 stays on one line */
  font-size: 14px;
  color: var(--vn-text);
  white-space: nowrap;
}

/* native range styling only: accent color, no custom track drawing */
input.vn-range {
  flex: 1 1 auto;
  min-width: 0; /* shrink instead of overflowing on narrow cards */
  height: 18px;
  margin: 0;
  padding: 0;
  accent-color: var(--vn-accent);
  cursor: pointer;
}

.vn-range-val {
  flex: 0 0 3.2em;
  text-align: right;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  color: var(--vn-text-faint);
}

/* --------------------------------------------------------------------------
   10. Title screen (star drift + sheen + start ring)
   -------------------------------------------------------------------------- */
.vn-title {
  position: absolute;
  inset: 0;
  z-index: 7;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 32px 20px;
  background: radial-gradient(
    120% 90% at 50% 30%,
    #101a30 0%,
    #0a1122 40%,
    #05080f 78%,
    #02040a 100%
  );
}

/* pure-CSS star field hint: a tiled field of 1-2px radial-gradient dots that
   drifts diagonally. .vn-title has a z-index, so z-index:-1 keeps the dots
   behind the text but above the title's own background. */
.vn-title::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.8;
  background-image:
    radial-gradient(1px 1px at 18% 26%, rgba(255, 255, 255, 0.85) 50%, transparent 51%),
    radial-gradient(1.4px 1.4px at 64% 18%, rgba(214, 230, 255, 0.8) 50%, transparent 51%),
    radial-gradient(1px 1px at 82% 44%, rgba(255, 255, 255, 0.6) 50%, transparent 51%),
    radial-gradient(1.2px 1.2px at 38% 12%, rgba(200, 220, 255, 0.7) 50%, transparent 51%),
    radial-gradient(1px 1px at 8% 62%, rgba(255, 255, 255, 0.5) 50%, transparent 51%),
    radial-gradient(1.6px 1.6px at 48% 34%, rgba(235, 244, 255, 0.9) 50%, transparent 51%),
    radial-gradient(1px 1px at 72% 68%, rgba(255, 255, 255, 0.45) 50%, transparent 51%),
    radial-gradient(1.2px 1.2px at 26% 48%, rgba(210, 228, 255, 0.65) 50%, transparent 51%);
  background-size: 340px 300px;
  background-repeat: repeat;
  animation: vn-star-drift 90s linear infinite;
}

/* engine-driven canvas starfield (stars + nebula + shooting stars); sits
   above the CSS dot hint, below the title text and start button */
.vn-title-canvas {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.vn-title > *:not(.vn-title-canvas) {
  position: relative;
  z-index: 1;
}

/* chapter card: translucent scrim + centered rules and text, shown once per
   distinct chapter string; fades via .vn-show, self-dismisses (engine) */
.vn-chapter {
  position: absolute;
  inset: 0;
  z-index: 6;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  background: radial-gradient(
    90% 70% at 50% 46%,
    rgba(4, 8, 18, 0.72) 0%,
    rgba(3, 6, 14, 0.55) 55%,
    rgba(2, 4, 10, 0.25) 100%
  );
  opacity: 0;
  transition: opacity 0.8s ease;
}

.vn-chapter.vn-show {
  opacity: 1;
}

.vn-chapter-text {
  font-size: clamp(22px, 4.4vw, 40px);
  font-weight: 500;
  letter-spacing: 0.42em;
  text-indent: 0.42em; /* balance the trailing letter-spacing */
  color: rgba(238, 244, 255, 0.94);
  text-shadow: 0 0 26px rgba(140, 180, 255, 0.35);
  padding: 22px 46px;
  border-top: 1px solid rgba(190, 214, 255, 0.4);
  border-bottom: 1px solid rgba(190, 214, 255, 0.4);
}

/* end credits: dark scrim over the ending scene; the roll column drifts
   upward once (18s, engine-timed) and any click/space skips to the title */
.vn-credits {
  position: absolute;
  inset: 0;
  z-index: 8;
  overflow: hidden;
  background: rgba(4, 7, 15, 0.82);
  transition: opacity 0.8s ease;
}

.vn-credits-roll {
  position: absolute;
  left: 50%;
  top: 100%;
  transform: translateX(-50%);
  text-align: center;
  width: min(88%, 620px);
}

.vn-credits-roll.vn-roll {
  animation: vn-credits-roll 18s linear forwards;
}

@keyframes vn-credits-roll {
  from {
    transform: translate(-50%, 0);
  }
  to {
    transform: translate(-50%, calc(-100% - 100vh));
  }
}

.vn-credits-role {
  margin-top: 34px;
  font-size: 12px;
  letter-spacing: 0.34em;
  text-indent: 0.34em;
  color: var(--vn-text-dim, rgba(200, 212, 232, 0.62));
}

.vn-credits-name {
  margin-top: 6px;
  font-size: 17px;
  font-weight: 500;
  color: rgba(238, 244, 255, 0.95);
}

.vn-credits-role.vn-credits-title {
  margin-top: 0;
}

.vn-credits-name.vn-credits-logo {
  font-size: clamp(26px, 5.4vw, 44px);
  letter-spacing: 0.3em;
  text-indent: 0.3em;
  text-shadow: 0 0 30px rgba(150, 190, 255, 0.4);
}

.vn-title-name {
  margin: 0;
  font-family: var(--vn-font-title);
  font-size: clamp(34px, 8vw, 64px);
  font-weight: 700;
  letter-spacing: 0.28em;
  text-indent: 0.28em; /* re-center: offsets the trailing letter-space */
  color: #f3f7ff; /* fallback for engines without background-clip: text */
  /* shimmering sheen: the gradient sweeps across the clipped text every 6s */
  background: linear-gradient(
    105deg,
    #f3f7ff 42%,
    #d9e9ff 49%,
    #ffffff 52%,
    #eaf2ff 55%,
    #f3f7ff 62%
  );
  background-size: 240% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: vn-sheen 6s ease-in-out infinite;
  /* text-shadow would bleed through the transparent fill; the glow rides on
     drop-shadow instead, which applies to the rendered gradient glyphs */
  filter:
    drop-shadow(0 0 18px rgba(140, 180, 255, 0.35))
    drop-shadow(0 3px 8px rgba(0, 0, 0, 0.55));
}

.vn-title-sub {
  margin-top: 14px;
  font-size: 13px;
  letter-spacing: 0.55em;
  text-indent: 0.55em;
  color: var(--vn-text-faint);
}

/* ending collector (结局收集): title-screen footnote — "结局回收 N/3" plus
   one pill per ending. Uncollected: dim outline + "？". Collected: the pill
   lights in the ending's own mood — bad = cold ash blue, good = dawn gold,
   true = the Betelgeuse warm red with a breathing glow. Deliberately quiet:
   a footnote between the subtitle and the start button, not a hero element. */
.vn-endings {
  margin-top: 26px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  user-select: none;
}

.vn-endings-count {
  font-size: 12px;
  letter-spacing: 0.4em;
  text-indent: 0.4em; /* trailing letter-space compensation, like .vn-title-sub */
  color: var(--vn-text-faint);
}

.vn-endings-marks {
  display: flex;
  align-items: center;
  gap: 14px;
}

.vn-ending-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 21px;
  height: 21px;
  padding: 0 8px;
  border-radius: 999px;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--vn-text-faint);
  border: 1px solid rgba(196, 210, 234, 0.22);
  background: rgba(8, 13, 26, 0.5);
  transition:
    color 0.5s ease,
    border-color 0.5s ease,
    box-shadow 0.5s ease;
}

/* collected pills pick up the scenario palette by ending mood */
.vn-ending-mark.vn-collected[data-ending="ending_bad"] {
  color: #c6d4ea;
  border-color: rgba(148, 174, 214, 0.5);
  box-shadow: 0 0 10px rgba(116, 148, 198, 0.3);
}

.vn-ending-mark.vn-collected[data-ending="ending_good"] {
  color: #ffe9c2;
  border-color: rgba(255, 210, 132, 0.5);
  box-shadow: 0 0 12px rgba(255, 196, 110, 0.32);
}

/* the true ending is the star itself: Betelgeuse warm red, breathing */
.vn-ending-mark.vn-collected[data-ending="ending_true"] {
  color: #ffd9c2;
  border-color: rgba(255, 140, 90, 0.62); /* #ff8c5a family */
  box-shadow: 0 0 13px rgba(255, 124, 92, 0.42);
  animation: vn-ending-breathe 3.2s ease-in-out infinite;
}

#vn-start {
  position: relative; /* anchors the ring pulse ::after */
  margin-top: 56px;
  padding: 17px 62px;
  border-radius: 999px;
  font-size: 17px;
  letter-spacing: 0.3em;
  text-indent: 0.3em;
  background: rgba(18, 28, 50, 0.55);
  border: 1px solid rgba(150, 190, 255, 0.45);
  color: #eaf1ff;
  animation: vn-breathe 3.4s ease-in-out infinite;
  transition:
    background 0.3s ease,
    border-color 0.3s ease,
    color 0.3s ease,
    box-shadow 0.3s ease,
    transform 0.2s ease;
}

/* expanding ring pulse around the start button */
#vn-start::after {
  content: "";
  position: absolute;
  inset: -4px;
  border-radius: inherit;
  border: 1px solid rgba(150, 190, 255, 0.55);
  pointer-events: none;
  animation: vn-ring 2.8s ease-out infinite;
}

#vn-start:hover {
  background: rgba(26, 38, 66, 0.7);
  border-color: rgba(180, 210, 255, 0.8);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 0 30px rgba(130, 175, 255, 0.45);
}

#vn-start:active {
  transform: translateY(0) scale(0.98);
}

/* bonus episode button (星语 · 后日谈): secondary entry under #vn-start,
   present in the layout only at 100% completion (engine toggles .vn-hidden).
   The warm-red border is the finale_star accent — a quiet hint at the
   afterglow epilogue. Deliberately quieter than the start button: smaller,
   translucent, no ring pulse and no breathe animation — transitions only,
   so no reduced-motion kill-list entry is needed. */
#vn-bonus {
  margin-top: 14px;
  padding: 8px 26px;
  border-radius: 999px;
  font-size: 14px;
  letter-spacing: 0.3em;
  text-indent: 0.3em; /* trailing letter-space compensation, like #vn-start */
  background: rgba(18, 28, 50, 0.35);
  border: 1px solid rgba(255, 140, 90, 0.55);
  color: var(--vn-text-dim);
  transition:
    background 0.3s ease,
    border-color 0.3s ease,
    color 0.3s ease,
    box-shadow 0.3s ease,
    transform 0.2s ease;
}

#vn-bonus:hover {
  background: rgba(42, 32, 34, 0.55);
  border-color: rgba(255, 170, 120, 0.8);
  color: #ffe9dd;
  transform: translateY(-1px);
  box-shadow: 0 0 16px rgba(255, 140, 90, 0.28);
}

#vn-bonus:active {
  transform: translateY(0) scale(0.98);
}

/* continue button (继续游戏): secondary entry between #vn-start and
   #vn-bonus, present in the layout only while a vn-save-* slot holds data
   (engine toggles .vn-hidden). Like #vn-bonus — smaller, translucent, no
   ring pulse and no breathe animation — but in the neutral blue-grey border
   family of #vn-start at reduced strength: no warm-red accent, this is the
   regular way back in, not an episode unlock. Transitions only, so no
   reduced-motion kill-list entry is needed. */
#vn-continue {
  margin-top: 12px;
  padding: 10px 32px;
  border-radius: 999px;
  font-size: 15px;
  letter-spacing: 0.3em;
  text-indent: 0.3em; /* trailing letter-space compensation, like #vn-start */
  background: rgba(18, 28, 50, 0.35);
  border: 1px solid rgba(150, 190, 255, 0.32);
  color: var(--vn-text-dim);
  transition:
    background 0.3s ease,
    border-color 0.3s ease,
    color 0.3s ease,
    box-shadow 0.3s ease,
    transform 0.2s ease;
}

#vn-continue:hover {
  background: rgba(24, 34, 58, 0.55);
  border-color: rgba(180, 210, 255, 0.6);
  color: #eaf1ff;
  transform: translateY(-1px);
  box-shadow: 0 0 14px rgba(130, 175, 255, 0.22);
}

#vn-continue:active {
  transform: translateY(0) scale(0.98);
}

/* --------------------------------------------------------------------------
   11. Toast
   -------------------------------------------------------------------------- */
.vn-toast {
  position: absolute;
  left: 50%;
  bottom: 140px;
  transform: translateX(-50%);
  z-index: 3;
  padding: 7px 18px;
  border-radius: 999px;
  max-width: 82vw;
  background: rgba(10, 16, 30, 0.88);
  border: 1px solid var(--vn-border);
  color: var(--vn-text-dim);
  font-size: 12.5px;
  letter-spacing: 0.05em;
  white-space: nowrap;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.4);
  opacity: 0; /* engine fades in by setting inline opacity */
  pointer-events: none;
  transition: opacity 0.35s ease;
}

/* --------------------------------------------------------------------------
   12. Cinematic overlays (vignette + film grain)
   Both are non-interactive fullscreen layers; the engine adds the elements
   and may place them anywhere — they stack above the stage (z 8 / 9) but
   never intercept input.
   -------------------------------------------------------------------------- */
.vn-vignette {
  position: absolute;
  inset: 0;
  z-index: 8;
  pointer-events: none;
  background: radial-gradient(
    ellipse at center,
    rgba(0, 0, 0, 0) 0%,
    rgba(0, 0, 0, 0) 52%,
    rgba(0, 0, 0, 0.32) 78%,
    rgba(0, 0, 0, 0.55) 100%
  );
}

/* film grain: three offset layers of sub-pixel radial-gradient dots produce
   a repeating noise pattern; the layer jitters a few px on a steps() curve.
   inset is -10px (not 0) so the translate jitter never exposes empty edges —
   see deviation notes. Static under prefers-reduced-motion. */
.vn-grain {
  position: absolute;
  inset: -10px;
  z-index: 9;
  pointer-events: none;
  opacity: 0.05;
  background-image:
    radial-gradient(rgba(255, 255, 255, 0.9) 0.5px, transparent 0.7px),
    radial-gradient(rgba(255, 255, 255, 0.55) 0.5px, transparent 0.7px),
    radial-gradient(rgba(0, 0, 0, 0.9) 0.5px, transparent 0.7px);
  background-size:
    3px 3px,
    4px 4px,
    5px 5px;
  background-position:
    0 0,
    1.2px 1.8px,
    2.4px 0.8px;
  animation: vn-grain-jitter 8s steps(1, end) infinite;
}

/* --------------------------------------------------------------------------
   13. Engine-toggle FX (glitch + shake)
   One-shot classes the engine can add and remove; CSS plays them once.
   -------------------------------------------------------------------------- */
.vn-text.vn-glitch {
  animation: vn-glitch 1.2s steps(1, end) 1;
}

#vn-app.vn-shake {
  animation: vn-shake 0.5s ease-in-out 1;
}

/* --------------------------------------------------------------------------
   14. Keyframes
   -------------------------------------------------------------------------- */
@keyframes vn-breathe {
  0%,
  100% {
    box-shadow:
      0 0 16px rgba(120, 168, 255, 0.22),
      0 0 46px rgba(100, 150, 255, 0.12);
  }
  50% {
    box-shadow:
      0 0 30px rgba(130, 178, 255, 0.45),
      0 0 70px rgba(100, 150, 255, 0.22);
  }
}

@keyframes vn-ring {
  0% {
    opacity: 0.7;
    transform: scale(0.96);
  }
  70%,
  100% {
    opacity: 0;
    transform: scale(1.22);
  }
}

@keyframes vn-sheen {
  0%,
  100% {
    background-position: 110% 0;
  }
  50% {
    background-position: -10% 0;
  }
}

@keyframes vn-star-drift {
  from {
    background-position: 0 0;
  }
  to {
    background-position: -340px 300px;
  }
}

@keyframes vn-sprite-breathe {
  from {
    transform: scaleY(1);
  }
  to {
    transform: scaleY(1.015);
  }
}

@keyframes vn-sprite-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* entrance: slide in from the character's own side of the screen (each
   .vn-pos-* sets --vn-enter-dx) while rising to the stage floor; no `to`
   frame — the sprite settles into its computed state (focus lift included).
   Solo nudges/focus transforms resume after the animation ends. */
@keyframes vn-sprite-rise {
  from {
    opacity: 0;
    transform: translate(var(--vn-enter-dx, 0px), 30px);
  }
}

/* exit: mirror the entrance (leave back the way they came) + fade;
   forwards fill holds it hidden until the engine drops the element
   (400ms window that allows a fast re-entry to reuse it) */
@keyframes vn-sprite-drop {
  to {
    opacity: 0;
    transform: translate(var(--vn-enter-dx, 0px), 34px);
  }
}

/* feel-swap pulse: quick dip-and-recover over the freshly swapped art */
@keyframes vn-swap-pulse {
  from {
    opacity: 0.25;
    transform: scale(0.985);
  }
}

@keyframes vn-dialog-in {
  from {
    transform: translateX(-50%) translateY(12px);
    opacity: 0;
  }
  to {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
  }
}

@keyframes vn-choice-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes vn-grain-jitter {
  0% { transform: translate(0, 0); }
  6% { transform: translate(-3px, 2px); }
  12% { transform: translate(2px, -3px); }
  18% { transform: translate(-2px, -2px); }
  24% { transform: translate(3px, 1px); }
  30% { transform: translate(-1px, 3px); }
  36% { transform: translate(3px, -2px); }
  42% { transform: translate(-3px, -1px); }
  48% { transform: translate(1px, 2px); }
  54% { transform: translate(-2px, 3px); }
  60% { transform: translate(2px, -1px); }
  66% { transform: translate(-3px, 1px); }
  72% { transform: translate(1px, -3px); }
  78% { transform: translate(3px, 2px); }
  84% { transform: translate(-2px, -3px); }
  90% { transform: translate(2px, 3px); }
  96%, 100% { transform: translate(0, 0); }
}

/* RGB-split glitch: red/cyan shadows split ±2px with tiny translate jitters;
   steps(1, end) makes every segment snap instead of tween. One-shot 1.2s. */
@keyframes vn-glitch {
  0% { text-shadow: none; transform: none; }
  6% {
    text-shadow: 2px 0 rgba(255, 64, 84, 0.8), -2px 0 rgba(64, 224, 255, 0.8);
    transform: translate(1px, -1px);
  }
  12% {
    text-shadow: -2px 0 rgba(255, 64, 84, 0.8), 2px 0 rgba(64, 224, 255, 0.8);
    transform: translate(-2px, 1px);
  }
  18% {
    text-shadow: 1px 0 rgba(255, 64, 84, 0.7), -1px 0 rgba(64, 224, 255, 0.7);
    transform: translate(2px, 0);
  }
  24% {
    text-shadow: none;
    transform: translate(-1px, 0);
  }
  30%, 52% {
    text-shadow: none;
    transform: none;
  }
  56% {
    text-shadow: 2px 0 rgba(255, 64, 84, 0.8), -2px 0 rgba(64, 224, 255, 0.8);
    transform: translate(-1px, 1px);
  }
  62% {
    text-shadow: -2px 1px rgba(255, 64, 84, 0.8), 2px -1px rgba(64, 224, 255, 0.8);
    transform: translate(2px, -1px);
  }
  68% {
    text-shadow: 1px 0 rgba(255, 64, 84, 0.6), -1px 0 rgba(64, 224, 255, 0.6);
    transform: translate(-1px, 0);
  }
  74%, 100% {
    text-shadow: none;
    transform: none;
  }
}

@keyframes vn-shake {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  10% { transform: translate(-6px, 2px) rotate(-0.3deg); }
  20% { transform: translate(5px, -3px) rotate(0.3deg); }
  30% { transform: translate(-6px, -2px) rotate(-0.3deg); }
  40% { transform: translate(6px, 2px) rotate(-0.3deg); }
  50% { transform: translate(-5px, 3px) rotate(-0.2deg); }
  60% { transform: translate(4px, -2px) rotate(0.2deg); }
  70% { transform: translate(-3px, 1px) rotate(-0.2deg); }
  80% { transform: translate(3px, -1px) rotate(0.15deg); }
  90% { transform: translate(-1px, 1px) rotate(0deg); }
}

/* collected true-ending pill: slow warm glow pulse (Betelgeuse breathing) */
@keyframes vn-ending-breathe {
  0%, 100% {
    box-shadow: 0 0 8px rgba(255, 124, 92, 0.3);
  }
  50% {
    box-shadow: 0 0 18px rgba(255, 140, 90, 0.58);
  }
}

/* --------------------------------------------------------------------------
   15. Responsive (down to 320px)
   -------------------------------------------------------------------------- */
@media (max-width: 640px) {
  .vn-sprites {
    height: 44vh;
  }

  .vn-sprite {
    width: clamp(150px, 40vw, 240px);
  }

  .vn-pos-left {
    left: 2vw;
  }

  .vn-pos-right {
    right: 2vw;
  }

  .vn-solo {
    left: 14vw;
  }
}

@media (max-width: 480px) {
  #vn-app {
    --vn-sprite-lift: 160px;
  }

  .vn-dialog {
    padding: 14px 16px;
    margin-bottom: 14px;
  }

  .vn-name {
    left: 16px;
    font-size: 12px;
    padding: 3px 16px 3px 11px;
  }

  .vn-text {
    font-size: 16px;
  }

  .vn-sprite {
    font-size: 38px;
  }

  .vn-toast {
    bottom: 122px;
    max-width: 90vw;
  }

  .vn-topbar {
    top: 10px;
    right: 10px;
  }

  button.vn-btn {
    padding: 0 10px;
  }

  .vn-title-name {
    letter-spacing: 0.18em;
    text-indent: 0.18em;
  }

  .vn-title-sub {
    letter-spacing: 0.4em;
    text-indent: 0.4em;
  }

  #vn-start {
    margin-top: 40px;
    padding: 15px 44px;
  }

  .vn-backlog {
    width: 92%;
    padding: 16px 18px;
  }

  .vn-menu {
    width: 92%;
    padding: 22px 18px;
  }

  .vn-settings {
    width: 92%;
    padding: 22px 18px;
  }

  .vn-setting-row {
    gap: 10px;
    padding: 12px;
  }
}

@media (max-width: 320px) {
  .vn-setting-row {
    gap: 8px;
    padding: 10px;
  }

  .vn-setting-row label {
    flex-basis: 4em;
    font-size: 13px;
  }

  .vn-range-val {
    flex-basis: 2.8em;
  }
}

/* --------------------------------------------------------------------------
   ---- mobile pass ---- (touch usability, additive + scoped)

   Everything here targets touch phones only; pointer: fine desktop rendering
   is unchanged (coarse-pointer rules never match a mouse, and max() with
   env() falls back to the existing offsets wherever the inset resolves to 0).
   Rules are ordered after section 15 so the small-screen restatements below
   win the cascade where both blocks apply. Safe-area insets additionally
   require viewport-fit=cover in the HTML viewport meta to report non-zero
   on iOS — CSS is ready either way.
   -------------------------------------------------------------------------- */

/* tap behavior: no grey tap flash on the app surface, no double-tap zoom
   while playing. touch-action: manipulation keeps pan + pinch-zoom working
   (backlog scrolling, accessibility zoom) and only kills the double-tap
   delay/zoom; the button reset above already carried the tap highlight. */
#vn-app {
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

#vn-app button {
  touch-action: manipulation;
}

/* safe areas: lift the dialog off the home indicator and the topbar chips
   out from under the notch. max() keeps the existing offsets as the floor,
   so desktop (env = 0) is pixel-identical; the 0px fallback degrades
   gracefully where env() is unknown. The 480px restatements preserve
   section 15's tighter offsets as the floor on small screens. */
#vn-app .vn-dialog {
  margin-bottom: max(24px, env(safe-area-inset-bottom, 0px));
}

#vn-app .vn-topbar {
  top: max(14px, env(safe-area-inset-top, 0px));
  right: max(14px, env(safe-area-inset-right, 0px));
}

@media (max-width: 480px) {
  #vn-app .vn-dialog {
    margin-bottom: max(14px, env(safe-area-inset-bottom, 0px));
  }

  #vn-app .vn-topbar {
    top: max(10px, env(safe-area-inset-top, 0px));
    right: max(10px, env(safe-area-inset-right, 0px));
  }
}

/* hit targets: 40px+ chips and close button, 44px+ slot/choice rows on
   touch devices. height: auto + min-height lets the fixed 32px chip grow;
   padding restores the pill shape at the larger size. */
@media (pointer: coarse) {
  button.vn-btn {
    height: auto;
    min-height: 40px;
    min-width: 40px;
    padding: 10px 14px;
  }

  button.vn-close {
    width: 40px;
    height: 40px;
  }

  button.vn-slot {
    min-height: 44px;
  }

  button.vn-choice {
    min-height: 44px;
  }
}

/* legibility at small widths: .vn-text already renders 16px here (>= the
   15px floor), so only the chapter title tracking needs relief — 0.42em
   spacing overflows ~10-character titles on a 360px screen. text-indent
   moves with it to keep the centered CJK compensation in step. */
@media (max-width: 480px) {
  .vn-chapter-text {
    letter-spacing: 0.2em;
    text-indent: 0.2em;
  }
}

/* landscape phones (short viewports): slimmer sprites (height scales with
   width, so heads clear the top too) and a narrower dialog so the portraits
   clear the name plate. Declared after section 15 so this width also wins
   where the <=640px sprite clamp would apply. */
@media (max-height: 480px) {
  .vn-sprite {
    width: clamp(140px, 22vw, 220px);
  }

  #vn-app .vn-dialog {
    width: min(92%, 560px);
    max-width: 560px;
  }
}

/* --------------------------------------------------------------------------
   16. Reduced motion — kills every new animation; grain and star field
   freeze in place (static texture is fine), transitions collapse.
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  #vn-app.vn-shake,
  #vn-app .vn-text.vn-glitch,
  #vn-app .vn-grain,
  #vn-app .vn-sprite > svg,
  #vn-app .vn-sprite.vn-enter,
  #vn-app .vn-sprite.vn-leave,
  #vn-app .vn-sprite.vn-swap > svg,
  #vn-app .vn-dialog.vn-enter,
  #vn-app .vn-choices button.vn-choice,
  #vn-app .vn-title::before,
  #vn-app .vn-title-name,
  #vn-app #vn-start,
  #vn-app #vn-start::after,
  #vn-app .vn-auto-bar i.vn-auto-run,
  #vn-app .vn-ending-mark.vn-collected[data-ending="ending_true"] {
    animation: none !important;
  }

  #vn-app,
  #vn-app *,
  #vn-app *::before,
  #vn-app *::after {
    transition-duration: 0.01ms !important;
  }
}

/* overlay entrance: re-runs on each display:none -> block toggle */
@keyframes vn-overlay-in {
  from {
    opacity: 0;
    transform: scale(0.985);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

#vn-app .vn-menu:not(.vn-hidden),
#vn-app .vn-settings:not(.vn-hidden),
#vn-app .vn-backlog:not(.vn-hidden) {
  animation: vn-overlay-in 0.28s ease-out;
}

/* ==========================================================================
   DEVIATION NOTES — contract classes styled differently on purpose
   --------------------------------------------------------------------------
   - .vn-backlog / .vn-menu: the contract describes a "fullscreen rgba backdrop
     + centered card" but the DOM has no separate card element. Each class is
     therefore styled as the centered card itself (min(90%, 640px) / 420px),
     and the fullscreen dim is produced with box-shadow: 0 0 0 100vmax
     rgba(3,6,12,.68/.72). Trade-off: no backdrop blur behind the card, only
     behind the card area itself.
   - .vn-sprites: pure CSS cannot measure the dialog height, so "above dialog"
     is a fixed lift (--vn-sprite-lift: 190px, 160px on small screens). The
     strip has no overflow clip, so a tall portrait may rise above its 52vh
     box — intended, waist-up figures keep their heads. Portraits are wide
     (clamp 200-340px, 150-240px under 640px) and absolutely positioned by
     slot: .vn-pos-left / .vn-pos-right at 6vw (2vw small), .vn-solo at 18vw
     for a lone character (the engine always slots a solo sprite at 0, and
     right:auto, so left/right never both apply).
   - .vn-sprite light pool: --vn-color survives only as the ::after ellipse
     beneath the character (rgba fallback then color-mix in one rule, so no
     @supports wrapper is needed). The z-index:-1 pseudo stays behind the
     portrait but inside .vn-sprites' stacking context, never under .vn-bg.
   - .vn-sprite filters share one property: the base drop-shadow is restated
     inside the sad grayscale chain and the dim saturate chain, and a combined
     [data-feel="sad"].vn-dim rule keeps both treatments composing instead of
     clobbering. Angry's warm rim is a second drop-shadow (no box to glow).
   - .vn-sprite breathing + crossfade: both ride on .vn-sprite > svg, so they
     are inert while the engine still renders plain text initials. The .3s
     vn-sprite-in fade re-runs on each innerHTML swap of the portrait
     (animation restarts on insertion); .vn-swap adds a shorter 0.18s
     vn-swap-pulse on top by restating the whole animation list (a bare later
     shorthand would otherwise drop breathe + in). CSS cannot otherwise
     transition a content swap.
   - .vn-sprite enter/leave: animations, not transitions, so they compose with
     the transitioned focus/dim transform. vn-sprite-rise has no `to` frame —
     the sprite settles into its current computed state (focus lift included).
     vn-sprite-drop uses forwards fill to stay hidden through the engine's
     400ms reuse window; .vn-leave also strips focus/dim/solo so the leaving
     figure exits the focus hierarchy. Title reset wipes the stage instantly
     (engine clearSpritesNow) — no exit animation on the title flow.
   - .vn-sprite feel vs focus: mood variants are declared before .vn-focus, so
     on a focused sprite the focus transform overrides the mood transform
     (sad's grayscale filter persists, its droop does not).
   - .vn-grain inset: -10px instead of 0 — the steps() translate jitter would
     expose 3px empty slivers at the edges at inset 0; the bleed layer drifts
     under the viewport edge instead. Static under prefers-reduced-motion.
   - .vn-bg.vn-fading: dip-to-black uses .3s while the class is on; removing
     it returns through the base .6s opacity curve (the "then back" half).
   - .vn-dialog.vn-enter / .vn-text.vn-glitch / #vn-app.vn-shake /
     .vn-bg.vn-fading: engine-toggle classes; the current engine does not emit
     them yet — CSS is ready and harmless if unused. vn-dialog-in keyframes
     carry translateX(-50%) so the entry animation never drops the centering.
   - .vn-dialog::before corner accent uses currentColor; until the engine sets
     a per-character color on .vn-dialog it rests on the base text tone (the
     name plate itself already carries the character color).
   - .vn-name: clip-path clips box-shadow, so its lift/glow uses filter:
     drop-shadow; the top-right bevel also leaves the border open on the cut
     diagonal, which reads as part of the angular plate look.
   - .vn-title-name sheen: text-shadow was replaced by drop-shadow filters —
     with background-clip:text + transparent fill, text-shadow bleeds through
     the glyphs and muddies the gradient. color is kept as a fallback.
   - .vn-title::before star field: needs the parent stacking context, which
     .vn-title already has (positioned + z-index). Dots are a repeating tile
     (340x300px) so the 90s drift loops seamlessly.
   - .vn-choice stagger: delays defined for up to 5 buttons; a 6th+ simply
     plays at the base 0s delay. `backwards` fill keeps them invisible during
     their delay window.
   - .vn-toast: "fade in/out via transition" implies the engine sets inline
     opacity; default is opacity: 0 with a 0.35s opacity transition. Toggling
     only .vn-hidden would appear instantly (display:none cannot transition).
     Positioned absolute (inside the fixed app root) rather than fixed.
   - .vn-name border: contract says "currentColor-ish"; uses color-mix to dim
     currentColor to 55% alpha when supported, falls back to a fixed accent
     rgba. Also hides itself under .vn-dialog.vn-narr defensively ("no name").
   - .vn-backlog-line: adds a faint bottom hairline between rows beyond the
     specified margin, for readability of long logs.
   - #vn-start / .vn-menu-title / .vn-title-sub: use text-indent equal to the
     letter-spacing so heavily tracked centered CJK text stays optically
     centered (trailing letter-space compensation).
   - html/body get a minimal reset (margin 0, dark background) since this is a
     standalone stylesheet; everything else is scoped to #vn-app.
   - .vn-settings reuses the .vn-menu card pattern verbatim (centered card +
     100vmax box-shadow dim + shared button.vn-close), so the same "no separate
     backdrop element" trade-off applies; .vn-range is styled natively
     (accent-color only, no track drawing) and rows are plain flex.
   ========================================================================== */