abstract：<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>边框</title> <!-- <link rel="icon" type="image/
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>边框</title>
<!-- <link rel="icon" type="image/x-icon"> -->
<style type="text/css">
*{margin: 0;padding: 0}
div{
width: 200px;
height: 200px;
margin: 50px auto;
border: dotted;
}
</style>
</head>
<body>
<hr>
<div >
</div>
</body>
Correcting teacher：天蓬老师Correction time：2019-03-28 09:50:42
Teacher's summary：你的边框也实在是太简单了吧, 很多样式都没有了