MediaWiki:Common.js

const audio = document.createElement('audio');
audio.src = 'https://d1rtq9slcl72gh.cloudfront.net/audio/home.mp3';
audio.loop = true;
audio.id = 'bgm';

const player = document.createElement('div');
player.innerHTML = `
  <button onclick="document.getElementById('bgm').play()">▶</button>
  <button onclick="document.getElementById('bgm').pause()">⏸</button>
`;
player.style.cssText = 'position:fixed;bottom:10px;right:10px;z-index:9999;background:#222;padding:10px;border-radius:8px';

document.body.appendChild(audio);
document.body.appendChild(player);

document.body.addEventListener('click', () => {
  audio.play().catch(() => {});
}, { once: true });