/* ==========================================================================
   Neon Stack 3D — Core Design System & Styling
   ========================================================================== */

:root {
  /* Color Palette - Neon Cyberpunk & Glassmorphism */
  --bg-space: #070913;
  --bg-card: rgba(16, 21, 38, 0.75);
  --bg-card-border: rgba(255, 255, 255, 0.12);
  --bg-card-hover: rgba(25, 33, 58, 0.85);

  --neon-cyan: #00f0ff;
  --neon-cyan-glow: rgba(0, 240, 255, 0.4);
  --neon-magenta: #ff007f;
  --neon-magenta-glow: rgba(255, 0, 127, 0.45);
  --neon-purple: #9d4edd;
  --neon-amber: #ffb703;
  --neon-emerald: #06d6a0;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --font-display: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;

  --shadow-neon: 0 0 20px rgba(0, 240, 255, 0.35);
  --shadow-card: 0 16px 40px -8px rgba(0, 0, 0, 0.65), 0 0 1px 1px rgba(255, 255, 255, 0.1);
  --transition-smooth: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Reset & Box Sizing */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  user-select: none;
  -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: var(--bg-space);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  touch-action: manipulation;
}

/* Cyber Ambient Background */
.ambient-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 70vw;
  height: 70vh;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(112, 0, 255, 0.15) 0%, rgba(0, 240, 255, 0.08) 40%, transparent 70%);
  filter: blur(80px);
  pointer-events: none;
  z-index: 1;
}

.cyber-grid {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 40%;
  background-image: 
    linear-gradient(rgba(0, 240, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 240, 255, 0.05) 1px, transparent 1px);
  background-size: 40px 40px;
  transform: perspective(600px) rotateX(60deg);
  transform-origin: bottom center;
  mask-image: linear-gradient(to top, rgba(0, 0, 0, 0.6) 0%, transparent 90%);
  -webkit-mask-image: linear-gradient(to top, rgba(0, 0, 0, 0.6) 0%, transparent 90%);
  pointer-events: none;
  z-index: 2;
}

/* Game Canvas */
#gameCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: block;
  z-index: 3;
}

/* HUD Overlay Layer */
.hud-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 24px 32px;
  pointer-events: none;
  z-index: 10;
}

/* Top Navigation Bar */
.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-cube {
  width: 18px;
  height: 18px;
  background: linear-gradient(135deg, var(--neon-cyan), var(--neon-magenta));
  transform: rotate(45deg);
  border-radius: 4px;
  box-shadow: 0 0 12px var(--neon-cyan);
  animation: floatCube 3s ease-in-out infinite alternate;
}

@keyframes floatCube {
  0% { transform: rotate(45deg) scale(0.95); }
  100% { transform: rotate(225deg) scale(1.08); }
}

.brand-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: 2px;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 4px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

.brand-title .accent-text {
  background: linear-gradient(90deg, var(--neon-cyan), #a855f7);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.badge-3d {
  font-size: 0.65rem;
  font-weight: 900;
  padding: 2px 6px;
  background: linear-gradient(135deg, var(--neon-magenta), #7928ca);
  color: white;
  border-radius: 4px;
  letter-spacing: 1px;
  box-shadow: 0 0 10px rgba(255, 0, 127, 0.4);
}

.hud-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  pointer-events: auto;
}

.icon-btn {
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  color: var(--text-secondary);
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: var(--transition-smooth);
}

.icon-btn:hover {
  color: var(--neon-cyan);
  border-color: var(--neon-cyan);
  transform: translateY(-2px);
  box-shadow: 0 0 16px var(--neon-cyan-glow);
}

.icon-btn:active {
  transform: translateY(0) scale(0.95);
}

.icon {
  width: 20px;
  height: 20px;
}

/* Floating Center Scoreboard */
.score-display {
  align-self: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
}

.current-score-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.current-score {
  font-family: var(--font-display);
  font-size: 5rem;
  font-weight: 800;
  line-height: 0.9;
  letter-spacing: -2px;
  color: #ffffff;
  text-shadow: 0 0 35px rgba(255, 255, 255, 0.3), 0 0 60px var(--neon-cyan-glow);
  transition: transform 0.15s ease-out;
}

.current-score.pop {
  transform: scale(1.18);
  color: var(--neon-cyan);
}

.score-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 4px;
  color: var(--text-muted);
  text-transform: uppercase;
}

.best-score-pill {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(16, 21, 38, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  backdrop-filter: blur(8px);
}

.best-score-pill strong {
  color: var(--neon-amber);
}

.trophy-icon {
  width: 14px;
  height: 14px;
  color: var(--neon-amber);
}

/* Combo Banner */
.combo-banner {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 18px;
  background: linear-gradient(90deg, rgba(255, 0, 127, 0.25), rgba(157, 78, 221, 0.25));
  border: 1px solid var(--neon-magenta);
  border-radius: 30px;
  color: #fff;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  box-shadow: 0 0 20px var(--neon-magenta-glow);
  animation: pulseCombo 0.8s ease-in-out infinite alternate;
}

@keyframes pulseCombo {
  0% { transform: scale(1); filter: drop-shadow(0 0 5px var(--neon-magenta)); }
  100% { transform: scale(1.08); filter: drop-shadow(0 0 15px var(--neon-magenta)); }
}

.combo-flame {
  font-size: 1.1rem;
}

/* Start / Drop Prompt */
.start-prompt {
  align-self: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  margin-bottom: 30px;
  pointer-events: none;
  animation: fadeInOut 2s ease-in-out infinite alternate;
}

@keyframes fadeInOut {
  0% { opacity: 0.65; transform: translateY(0); }
  100% { opacity: 1; transform: translateY(-6px); }
}

.pulse-indicator {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.key-pill, .touch-pill {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 6px 16px;
  border-radius: 8px;
  color: var(--neon-cyan);
  font-weight: 700;
  font-family: var(--font-display);
  letter-spacing: 1px;
  box-shadow: 0 0 10px var(--neon-cyan-glow);
}

.prompt-subtitle {
  font-size: 0.9rem;
  color: var(--text-secondary);
  letter-spacing: 0.5px;
}

/* Modal Overlay & Glass Card */
.modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(5, 7, 15, 0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 100;
  opacity: 1;
  visibility: visible;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  border-radius: 24px;
  padding: 40px 36px;
  max-width: 440px;
  width: 100%;
  box-shadow: var(--shadow-card);
  text-align: center;
  overflow: hidden;
  animation: cardEntrance 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes cardEntrance {
  0% { transform: translateY(24px) scale(0.94); opacity: 0; }
  100% { transform: translateY(0) scale(1); opacity: 1; }
}

.modal-glow-edge {
  position: absolute;
  top: 0;
  left: 10%;
  right: 10%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--neon-cyan), var(--neon-magenta), transparent);
}

.new-best-badge {
  display: inline-block;
  background: linear-gradient(90deg, var(--neon-amber), #ff6b6b);
  color: #000;
  font-weight: 800;
  font-size: 0.75rem;
  padding: 4px 14px;
  border-radius: 20px;
  letter-spacing: 1px;
  margin-bottom: 12px;
  box-shadow: 0 0 16px rgba(255, 183, 3, 0.5);
}

.modal-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: 2px;
  margin-bottom: 24px;
  background: linear-gradient(135deg, #ffffff, var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 28px;
}

.stat-box {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 16px;
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-box.primary-stat {
  grid-column: span 2;
  background: linear-gradient(135deg, rgba(0, 240, 255, 0.08), rgba(157, 78, 221, 0.08));
  border-color: rgba(0, 240, 255, 0.25);
}

.stat-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--text-muted);
  text-transform: uppercase;
}

.stat-value {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 800;
  color: #fff;
}

.stat-box.primary-stat .stat-value {
  font-size: 2.8rem;
  color: var(--neon-cyan);
  text-shadow: 0 0 20px var(--neon-cyan-glow);
}

/* Modal Actions */
.modal-actions {
  display: flex;
  justify-content: center;
}

.btn-action {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  padding: 16px 36px;
  border-radius: 14px;
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  transition: var(--transition-smooth);
}

.primary-btn {
  background: linear-gradient(135deg, var(--neon-cyan), #00a2ff);
  color: #050914;
  box-shadow: 0 4px 24px var(--neon-cyan-glow);
}

.primary-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 32px rgba(0, 240, 255, 0.6);
  filter: brightness(1.1);
}

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

.btn-icon {
  width: 20px;
  height: 20px;
}

.hint-key {
  margin-top: 16px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

kbd {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 4px;
  padding: 2px 6px;
  font-size: 0.75rem;
  color: var(--neon-cyan);
  font-family: monospace;
}

/* Help Modal Specifics */
.help-card {
  max-width: 500px;
  text-align: left;
}

.btn-close {
  position: absolute;
  top: 18px;
  right: 20px;
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.8rem;
  cursor: pointer;
  line-height: 1;
  transition: var(--transition-smooth);
}

.btn-close:hover {
  color: #fff;
  transform: scale(1.15);
}

.instructions-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
  margin-bottom: 30px;
}

.instruction-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.instruction-num {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(0, 240, 255, 0.1);
  border: 1px solid var(--neon-cyan);
  color: var(--neon-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-family: var(--font-display);
  flex-shrink: 0;
}

.instruction-body strong {
  display: block;
  font-size: 1rem;
  color: #ffffff;
  margin-bottom: 2px;
}

.instruction-body p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.instruction-body em {
  color: var(--neon-magenta);
  font-style: normal;
  font-weight: 600;
}

/* Utilities */
.hidden {
  display: none !important;
}

/* Responsive Adjustments */
@media (max-width: 600px) {
  .hud-container {
    padding: 16px 20px;
  }

  .brand-title {
    font-size: 1.25rem;
  }

  .current-score {
    font-size: 4rem;
  }

  .modal-card {
    padding: 30px 24px;
    border-radius: 20px;
  }

  .modal-title {
    font-size: 1.6rem;
  }

  .stat-box.primary-stat .stat-value {
    font-size: 2.2rem;
  }

  .stat-value {
    font-size: 1.4rem;
  }
}