css_盒子
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="Generator" content="EditPlus®">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
<title>css_盒子</title>
<style type="text/css">
body{border: 1px solid black; }
div{border: 1px solid red;margin: 10px;padding: 20px;}
</style>
</head>
<body>
<div>我是盒子</div>
</body>
</html>