/* ---- Reset & Root Variables ---- */
:root {
  --bg:           #0d0d0f;
  --panel-bg:     #13131a;
  --border:       rgba(255,255,255,0.08);
  --text:         #e0e0e0;
  --text-dim:     rgba(255,255,255,0.4);
  --accent:       #00F5FF;
  --radius:       8px;
  --panel-shadow: 0 4px 24px rgba(0,0,0,0.6);
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  min-height: 100vh;
  overflow-x: hidden;
  background-image: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0,0,0,0.03) 2px,
    rgba(0,0,0,0.03) 4px
  );
}

/* ---- Header ---- */
header {
  text-align: center;
  padding: 10px 0 4px;
  width: 100%;
}
header h1 {
  font-size: clamp(16px, 3.5vw, 28px);
  font-weight: 900;
  letter-spacing: 10px;
  text-transform: uppercase;
  color: var(--accent);
  text-shadow: 0 0 16px var(--accent), 0 0 32px rgba(0,245,255,0.3);
}

/* ---- Game Container ---- */
#game-container {
  display: grid;
  grid-template-columns: 110px auto 110px;
  grid-template-areas: "hold board right";
  gap: 10px;
  align-items: start;
  padding: 8px 16px 0;
}

/* ---- Board Canvas ---- */
#board-wrap {
  grid-area: board;
  display: flex;
  justify-content: center;
}

#board {
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 0 40px rgba(0,245,255,0.05), var(--panel-shadow);
  transition: box-shadow 0.15s ease;
}
#board.flash {
  box-shadow: 0 0 60px rgba(255,255,255,0.45), 0 0 20px rgba(0,245,255,0.3), var(--panel-shadow);
}

/* ---- Side Panels ---- */
.panel {
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 8px;
  box-shadow: var(--panel-shadow);
}
#hold-panel {
  grid-area: hold;
}
#right-panel {
  grid-area: right;
}

.panel-label {
  font-size: 9px;
  letter-spacing: 2.5px;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 6px;
  text-align: center;
}

#hold-canvas,
#next-canvas {
  display: block;
  margin: 0 auto;
}

/* ---- Stats ---- */
.stat-block {
  margin-top: 14px;
  text-align: center;
}
.stat-label {
  font-size: 8px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 2px;
}
.stat-value {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent);
  text-shadow: 0 0 10px var(--accent);
  font-variant-numeric: tabular-nums;
  letter-spacing: 1px;
}

/* ---- Pause Button (desktop) ---- */
.pause-btn {
  display: block;
  width: 100%;
  margin-top: 16px;
  padding: 8px 0;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-dim);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s, box-shadow 0.15s;
}
.pause-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 10px rgba(0,245,255,0.2);
}

/* ---- Overlay (Start / Pause / Game Over) ---- */
#overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.78);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  z-index: 100;
}
#overlay.hidden { display: none; }

#overlay-title {
  font-size: clamp(32px, 7vw, 56px);
  font-weight: 900;
  letter-spacing: 6px;
  text-transform: uppercase;
  color: var(--accent);
  text-shadow: 0 0 20px var(--accent), 0 0 40px var(--accent);
  animation: pulse-glow 2.4s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% {
    text-shadow: 0 0 20px var(--accent), 0 0 40px var(--accent);
  }
  50% {
    text-shadow: 0 0 40px var(--accent), 0 0 80px var(--accent), 0 0 120px rgba(0,245,255,0.4);
  }
}

#overlay-score {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 1px;
}
#overlay-score.hidden { display: none; }

#overlay-btn {
  padding: 14px 52px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--bg);
  background: var(--accent);
  border: none;
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 0 20px var(--accent), 0 0 40px rgba(0,245,255,0.3);
  transition: transform 0.1s, box-shadow 0.1s;
}
#overlay-btn:hover {
  transform: scale(1.06);
  box-shadow: 0 0 32px var(--accent), 0 0 64px rgba(0,245,255,0.4);
}
#overlay-btn:active {
  transform: scale(0.97);
}

.controls-hint {
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing: 0.5px;
  text-align: center;
  max-width: 320px;
  line-height: 1.6;
}

/* ---- Mobile Touch Controls ---- */
#touch-controls {
  display: none;
  grid-template-columns: repeat(6, 1fr);
  gap: 6px;
  width: 100%;
  max-width: 400px;
  padding: 10px 12px 16px;
}
.touch-btn {
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 18px;
  padding: 14px 0;
  text-align: center;
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  transition: background 0.1s, box-shadow 0.1s;
  touch-action: manipulation;
}
.touch-btn:active {
  background: rgba(0,245,255,0.12);
  box-shadow: 0 0 10px rgba(0,245,255,0.3);
  color: var(--accent);
}

/* ---- Responsive ---- */
@media (max-width: 580px) {
  header {
    padding: 8px 0 2px;
  }

  #game-container {
    grid-template-columns: 90px auto 90px;
    gap: 6px;
    padding: 4px 8px 0;
  }

  .panel {
    padding: 8px 5px;
  }

  .stat-value {
    font-size: 17px;
  }

  #touch-controls {
    display: grid;
  }
}

@media (max-width: 420px) {
  #game-container {
    grid-template-columns: 76px auto 76px;
    gap: 4px;
    padding: 4px 4px 0;
  }

  #hold-canvas,
  #next-canvas {
    width: 76px !important;
    height: 62px !important;
  }

  .stat-value {
    font-size: 14px;
  }
  .stat-label {
    font-size: 7px;
  }
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }