<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>css的外部样式</title>
<!-- <link rel="stylesheet" href="ess/demo.css"> -->
<style>
@import url(demo.css)
</style>
</head>
<body>
<h2>CSS层叠样式</h2>
<p>用于定义HTML内容在浏览器中的显示样式</p>
</body>
</html>