制作一个边框样式
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>边框</title>
<style type="text/css">
.box{
width: 300px;
height: 300px;
border: 1px solid red;
}
</style>
</head>
<body>
<div></div>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>边框</title>
<style type="text/css">
.box{
width: 300px;
height: 300px;
border: 1px solid red;
}
</style>
</head>
<body>
<div></div>
</body>
</html>