/* ============================================================
   PREMIUM LAYER – Scape The Trap
   Loaded AFTER style.css. Pure enhancement layer:
   - Vercel-inspired tokens (DESIGN.md) adapted to dark/gold brand
   - Stacked shadows + inset hairline rings (never heavy drops)
   - Negative-tracking display type, mono technical labels
   - GPU-friendly transitions (transform/opacity only)
   - Reduced-motion + low-power fallbacks
   Nothing here removes original styling — it only refines it.
   ============================================================ */

:root {
  /* Brand (existing, preserved) */
  --stt-gold: #FFD700;
  --stt-gold-deep: #FF8C00;
  --stt-ink-bg: #0a0a0a;

  /* Vercel-derived neutrals (DESIGN.md) */
  --v-ink: #171717;
  --v-body: #4d4d4d;
  --v-hairline-strong: #a1a1a1;
  --v-link: #0070f3;

  /* Signature gradients — used ONLY at accent scale */
  --v-grad-develop: linear-gradient(90deg, #007cf0, #00dfd8);
  --v-grad-preview: linear-gradient(90deg, #7928ca, #ff0080);
  --v-grad-ship:    linear-gradient(90deg, #ff4d4d, #f9cb28);

  /* Radii (DESIGN.md rounded scale) */
  --r-sm: 6px; --r-md: 8px; --r-lg: 12px; --r-xl: 16px; --r-pill: 100px;

  /* Elevation — stacked soft shadows + inset hairline (Levels 2–5) */
  --elev-2: 0 1px 1px rgba(0,0,0,.05), 0 2px 2px rgba(0,0,0,.10);
  --elev-3: 0 2px 2px rgba(0,0,0,.10), 0 8px 8px -8px rgba(0,0,0,.35);
  --elev-4: 0 2px 2px rgba(0,0,0,.12), 0 8px 16px -4px rgba(0,0,0,.45);
  --elev-5: 0 1px 1px rgba(0,0,0,.05), 0 8px 16px -4px rgba(0,0,0,.50),
             0 24px 32px -8px rgba(0,0,0,.60);
  --ring-inset: inset 0 0 0 1px rgba(255,255,255,.07);

  /* Type stacks — Geist substitutes (system-first, zero network cost) */
  --font-sans: 'Geist', Inter, system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Geist Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* Motion */
  --ease-out: cubic-bezier(.16, 1, .3, 1);
  --dur-fast: 120ms;
  --dur-med: 220ms;
}

/* ===== BASE REFINEMENTS ===== */
html, body {
  font-family: var(--font-sans);
  -webkit-tap-highlight-color: transparent;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

/* Accessible focus ring — Vercel link blue */
button:focus-visible,
input:focus-visible,
.level-card:focus-visible {
  outline: 2px solid var(--v-link);
  outline-offset: 2px;
  border-radius: var(--r-md);
}

/* ===== TITLE TREATMENT — display voice ===== */
.game-title-big {
  letter-spacing: -0.02em;                 /* negative tracking = premium voice */
  background: linear-gradient(180deg, #FFE97A 0%, var(--stt-gold) 55%, var(--stt-gold-deep) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 32px rgba(255,215,0,.35)) drop-shadow(0 2px 4px rgba(0,0,0,.6));
}

/* Hero-scale gradient hairline under menu title — the one decorative moment */
.menu-logo { position: relative; padding-bottom: 14px; }
.menu-logo::after {
  content: '';
  position: absolute; left: 50%; bottom: 0;
  width: min(240px, 60vw); height: 2px;
  transform: translateX(-50%);
  border-radius: 9999px;
  background: var(--v-grad-develop);
  opacity: .85;
  box-shadow: 0 0 18px rgba(0, 223, 216, .45);
}

/* ===== BUTTONS — stacked shadows + micro-interactions ===== */
.btn-gold {
  border-radius: var(--r-pill);                       /* marketing pill (DESIGN.md) */
  font-family: var(--font-sans);
  font-weight: 600;                                   /* display ceiling */
  letter-spacing: .04em;
  box-shadow: 0 4px 20px rgba(255,180,0,.35),
              var(--elev-2),
              inset 0 1px 0 rgba(255,255,255,.35);    /* crisp top edge */
  transition: transform var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-med) var(--ease-out),
              filter var(--dur-med) ease;
}
.btn-gold:hover {
  transform: translateY(-2px);
  filter: brightness(1.05);
}
.btn-gold:active {
  transform: translateY(0) scale(.985);
  box-shadow: 0 2px 10px rgba(255,180,0,.3), inset 0 1px 0 rgba(255,255,255,.25);
}

.btn-dark {
  border-radius: var(--r-md);                          /* in-app radius (6–8px) */
  font-weight: 500;
  box-shadow: var(--elev-2), var(--ring-inset);
  transition: background var(--dur-med) ease,
              transform var(--dur-fast) var(--ease-out),
              border-color var(--dur-med) ease;
}
.btn-dark:hover {
  background: rgba(255,255,255,.13);
  border-color: rgba(255,200,40,.35);
  transform: translateY(-1px);
}
.btn-dark:active { transform: translateY(0) scale(.99); }

/* ===== PANELS — modal elevation (Level 5) ===== */
.name-box,
.overlay-panel,
.overlay-panel-sm {
  box-shadow: var(--elev-5), var(--ring-inset),
              0 0 60px rgba(255,200,40,.06);
}
.overlay-panel-sm {
  animation: panel-in var(--dur-med) var(--ease-out);
}
@keyframes panel-in {
  from { opacity: 0; transform: translate(-50%, -48%) scale(.96); }
  to   { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

/* ===== INPUTS — form-input voice ===== */
#player-name-input {
  height: 48px;                                        /* form-input-lg */
  border-radius: var(--r-sm);
  background: rgba(255,255,255,.06);
  transition: border-color var(--dur-med) ease, box-shadow var(--dur-med) ease;
}
#player-name-input:focus {
  border-color: var(--stt-gold);
  box-shadow: 0 0 0 3px rgba(255,215,0,.15);
}

/* ===== LEVEL / GARAGE CARDS — card chrome ===== */
.level-card,
.garage-card {
  box-shadow: var(--elev-2), var(--ring-inset);
  transition: background var(--dur-med) ease,
              transform var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-med) var(--ease-out),
              border-color var(--dur-med) ease;
}
.level-card:hover:not(.locked),
.garage-card:not(.equipped):hover {
  transform: translateY(-2px);
  box-shadow: var(--elev-4), var(--ring-inset),
              0 0 24px rgba(255,200,40,.12);
  border-color: rgba(255,200,40,.4);
}
.level-card:active:not(.locked) { transform: translateY(0) scale(.97); }
.garage-card.equipped {
  box-shadow: 0 0 0 1px var(--stt-gold), var(--elev-3);
}

/* ===== HUD — mono technical labels (caption-mono voice) ===== */
#hud-level, #hud-deaths, #hud-timer, #hud-stars {
  font-family: var(--font-mono);
  letter-spacing: 0;
  text-shadow: 0 1px 3px rgba(0,0,0,.7);
}
#btn-pause {
  border-radius: var(--r-sm);
  font-size: .95rem;
  box-shadow: var(--elev-2), var(--ring-inset);
  transition: background var(--dur-med) ease, transform var(--dur-fast) var(--ease-out);
}
#btn-pause:active { transform: translateX(-50%) scale(.95); }

/* ===== TOGGLES & SLIDERS — tactile polish ===== */
.toggle input:checked + .slider {
  background: var(--stt-gold);
  box-shadow: 0 0 12px rgba(255,215,0,.35);
}
.vol-slider {
  height: 5px;
  border-radius: 9999px;
  transition: opacity var(--dur-med) ease;
}
.vol-slider::-webkit-slider-thumb {
  width: 18px; height: 18px;
  border: 2px solid rgba(0,0,0,.55);
  box-shadow: 0 1px 4px rgba(0,0,0,.5);
  transition: transform var(--dur-fast) ease;
}
.vol-slider::-webkit-slider-thumb:hover { transform: scale(1.15); }

/* ===== LEADERBOARD rows — hairline rhythm ===== */
.lb-row { transition: background var(--dur-fast) ease; }
.lb-row:hover { background: rgba(255,200,40,.05); }

/* ===== DEATH FLASH — smoother ===== */
#death-flash { opacity: 0; }
#death-flash:not(.hidden) { opacity: 1; }

/* ===== SCROLLBAR — quieter ===== */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-thumb { background: rgba(255,200,40,.22); border-radius: 9999px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255,200,40,.38); }

/* ===== REDUCED MOTION — respect OS setting ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}

/* ===== LOW-END FALLBACK — drop expensive effects when device flags itself ===== */
@media (prefers-reduced-transparency: reduce) {
  .name-box, .overlay-panel, .overlay-panel-sm { backdrop-filter: none !important; }
}