body {
  margin: 0;
  padding: 0;
  background: black;
  color: lime;
  font-family: monospace;
  text-align: center;
}

h1 {
  margin-top: 10px;
}

.space-blaster {
  position: relative;
  width: 480px;
  margin: 20px auto;
  border: 2px solid lime;
  background: #111;
}

.sb-header {
  color: lime;
  font-family: monospace;
  text-align: center;
  padding: 5px;
  font-size: 16px;
}

.sb-canvas {
  display: block;
  background: #111;
}