html, body {
  margin: 0;
  padding: 0;
  background: #0e0e12;
  height: 100%;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

#game {
  display: block;
  margin: 40px auto;
  background: #111827;
  border: 2px solid #1f2937;
  box-shadow: 0 10px 30px rgba(0,0,0,0.4);
}