body {
  margin: 0;
  padding: 0;
  background: #000;
  overflow: hidden;
  font-family: 'Courier New', monospace;
}

#gameCanvas {
  display: block;
  margin: 0 auto;
  background: radial-gradient(circle at center, #1a0033 0%, #000 100%);
}

#ui {
  position: absolute;
  top: 10px;
  left: 10px;
  color: #fff;
  font-size: 20px;
  text-shadow: 2px 2px 4px #000;
}

#gameOver {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: #ff0;
  font-size: 40px;
  display: none;
}