html, body { margin: 0; padding: 0; background: #111; }
canvas { display: block; margin: 0 auto; }
#instructions {
  max-width: 800px;
  margin: 20px auto;
  padding: 15px 20px;
  background: #111;
  color: #fff;
  font-family: Arial, sans-serif;
  border-radius: 10px;
}

#instructions h3 {
  margin-top: 0;
}

#instructions ul {
  padding-left: 20px;
}

#exitBtn {
  margin-top: 12px;
  padding: 8px 14px;
  font-size: 14px;
  border: none;
  border-radius: 6px;
  background: #c0392b;
  color: white;
  cursor: pointer;
}

#exitBtn:hover {
  background: #e74c3c;
}