/* ============================================
   TETRIS GAME — STYLES
   ============================================ */

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

:root {
  --bg-dark: #0a0a1a;
  --bg-panel: #12122a;
  --bg-panel-2: #1a1a3a;
  --border-color: #2a2a5a;
  --accent: #7c3aed;
  --accent-glow: rgba(124, 58, 237, 0.4);
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-accent: #a78bfa;

  /* Tetromino colors */
  --color-I: #06b6d4;
  --color-O: #f59e0b;
  --color-T: #a855f7;
  --color-S: #22c55e;
  --color-Z: #ef4444;
  --color-J: #3b82f6;
  --color-L: #f97316;
  --color-ghost: rgba(255, 255, 255, 0.08);
}

body {
  background: var(--bg-dark);
  color: var(--text-primary);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background-image:
    radial-gradient(ellipse at 20% 50%, rgba(124, 58, 237, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(6, 182, 212, 0.06) 0%, transparent 50%);
}

/* ── Header ── */
header {
  text-align: center;
  margin-bottom: 20px;
}

header h1 {
  font-size: 2.5rem;
  font-weight: 900;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  background: linear-gradient(135deg, #a78bfa 0%, #06b6d4 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: none;
  filter: drop-shadow(0 0 20px rgba(124, 58, 237, 0.5));
}

header p {
  color: var(--text-secondary);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  margin-top: 4px;
}

/* ── Main Layout ── */
.game-wrapper {
  display: flex;
  align-items: flex-start;
  gap: 20px;
}

/* ── Side Panels ── */
.side-panel {
  width: 130px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.panel-box {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 14px;
  position: relative;
  overflow: hidden;
}

.panel-box::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(124,58,237,0.05), transparent);
  pointer-events: none;
}

.panel-label {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-accent);
  margin-bottom: 10px;
}

.panel-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

/* ── Preview Canvas (Next & Hold) ── */
.preview-canvas-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 4px;
}

canvas.preview {
  display: block;
}

/* ── Main Canvas ── */
.canvas-wrap {
  position: relative;
}

canvas#gameCanvas {
  display: block;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  box-shadow:
    0 0 40px rgba(124, 58, 237, 0.2),
    inset 0 0 30px rgba(0, 0, 0, 0.4);
}

/* ── Overlay (Start / Pause / Game Over) ── */
#overlay {
  position: absolute;
  inset: 0;
  background: rgba(10, 10, 26, 0.88);
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  backdrop-filter: blur(4px);
  z-index: 10;
}

#overlay.hidden {
  display: none;
}

#overlay h2 {
  font-size: 2rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: linear-gradient(135deg, #a78bfa, #06b6d4);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

#overlay p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  text-align: center;
  line-height: 1.6;
}

#overlay .score-display {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--text-accent);
}

.btn {
  background: linear-gradient(135deg, #7c3aed, #4f46e5);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 12px 32px;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 4px 20px rgba(124, 58, 237, 0.4);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(124, 58, 237, 0.6);
}

.btn:active {
  transform: translateY(0);
}

/* ── Controls Info ── */
.controls-info {
  margin-top: 16px;
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 12px 14px;
  width: 100%;
}

.controls-info .panel-label {
  margin-bottom: 8px;
}

.control-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
  font-size: 0.72rem;
  color: var(--text-secondary);
}

.control-row:last-child {
  margin-bottom: 0;
}

kbd {
  background: var(--bg-panel-2);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 0.65rem;
  font-family: inherit;
  color: var(--text-accent);
  white-space: nowrap;
}

/* ── Level indicator ── */
.level-bar-wrap {
  margin-top: 6px;
}

.level-bar-bg {
  background: var(--bg-panel-2);
  border-radius: 4px;
  height: 5px;
  overflow: hidden;
}

.level-bar-fill {
  background: linear-gradient(90deg, #7c3aed, #06b6d4);
  height: 100%;
  border-radius: 4px;
  transition: width 0.3s ease;
}

/* ── Line clear flash ── */
@keyframes rowFlash {
  0%   { background: white; }
  100% { background: transparent; }
}

/* ── Mobile fallback message ── */
.mobile-msg {
  display: none;
  text-align: center;
  padding: 40px 20px;
  color: var(--text-secondary);
}

@media (max-width: 600px) {
  .game-wrapper,
  header {
    display: none;
  }
  .mobile-msg {
    display: block;
  }
}