html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: #111;
  color: #eee;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Arial, "Apple Color Emoji", "Segoe UI Emoji";
}

#game {
  display: block;
}

.hud {
  position: fixed;
  left: 12px;
  top: 12px;
  background: rgba(0,0,0,0.45);
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 14px;
}