<!DOCTYPE html>
<html>
<body>
<h1>Window 对象</h1>
<h2>innerWidth 和 innerHeight 属性</h2>
<p id="demo"></p>
<script>
let w = innerWidth;
let h = innerHeight;
document.getElementById("demo").innerHTML = "宽度：" + w + "<br>高度：" + h;
</script>
</body>
</html>