body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #000;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  overflow: hidden;
}
#game-container {
  text-align: center;
}
canvas {
  background: radial-gradient(circle at center, #111 0%, #000 80%);
  border: 4px solid #0ff;
  display: block;
  margin: auto;
}
#info {
  margin-top: 12px;
  font-size: 18px;
}
#gameOver {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0,0,0,.85);
  border: 2px solid #0ff;
  border-radius: 10px;
  padding: 20px;
  color: #0ff;
  display: none;
  width: 280px;
}
#gameOver h1 { margin: 0 0 12px; }
#gameOver button {
  background: #0ff;
  border: none;
  color: #000;
  font-size: 16px;
  padding: 10px 14px;
  border-radius: 6px;
  cursor: pointer;
}