<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<!-- 以下style是内部样式表 -->
<style>
#div1 {width:100px;
height:100px;
background-color:pink;
font-size:60px;
}
</style>
<!-- 以下是外部样式表引入 -->
<link rel="stylesheet" href="css/css.css"/>
</head>
<body>
<div id="div1">aaa</div>
<div id="div2">bbb</div>
</body>
</html>