HTML/CSS/JS Playground

HTML <h1>你好，世界</h1> <p>开始编写你的代码吧。</p> <button id="btn">点击测试</button>

CSS body { font-family: sans-serif; padding: 20px; } h1 { color: #007acc; } button { padding: 10px; background: #2d2d2d; color: #fff; border: none; cursor: pointer; }

JavaScript document.getElementById('btn').onclick = function() { alert('JS 运行成功！'); };