:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --accent: #22c55e;
  --accent-dim: #16a34a;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --danger: #ef4444;
}

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

body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at 50% 20%, #1e293b 0%, var(--bg) 70%);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  color: var(--text);
  padding: 16px;
}

.game-wrapper {
  width: 100%;
  max-width: 440px;
  background: var(--panel);
  border-radius: 20px;
  padding: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

h1 { font-size: 1.5rem; font-weight: 700; letter-spacing: 0.5px; }

.stats { display: flex; gap: 12px; }

.stat {
  background: var(--bg);
  border-radius: 12px;
  padding: 6px 14px;
  text-align: center;
  min-width: 72px;
}

.label {
  display: block;
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
}

.value { font-size: 1.25rem; font-weight: 700; color: var(--accent); }

.board-wrap {
  position: relative;
  border-radius: 14px;
  overflow: hidden;
  background: var(--bg);
  border: 2px solid rgba(34, 197, 94, 0.25);
}

canvas {
  display: block;
  width: 100%;
  height: auto;
  background: var(--bg);
}

.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  background: rgba(15, 23, 42, 0.88);
  backdrop-filter: blur(3px);
  text-align: center;
  padding: 16px;
}

.overlay.hidden { display: none; }

.overlay h2 { font-size: 1.8rem; color: var(--accent); }

.overlay p { color: var(--muted); font-size: 0.95rem; }

kbd {
  background: var(--panel);
  border: 1px solid var(--muted);
  border-bottom-width: 2px;
  border-radius: 6px;
  padding: 2px 8px;
  font-size: 0.85rem;
}

.btn {
  margin-top: 6px;
  background: var(--accent);
  color: #052e16;
  border: none;
  border-radius: 12px;
  padding: 12px 32px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease;
}

.btn:hover { background: #4ade80; transform: translateY(-2px); }

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

footer { margin-top: 14px; text-align: center; }

.hint { color: var(--muted); font-size: 0.8rem; }

@media (max-width: 480px) {
  .game-wrapper { padding: 14px; }
  h1 { font-size: 1.2rem; }
  .stat { min-width: 60px; padding: 4px 10px; }
  .value { font-size: 1.05rem; }
}