abstract：<!DOCTYPE html><html><head> <meta charset="utf-8"> <title>边框</title> <link rel="shortcut icon" type="image/x-icon" href=""
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>边框</title>
<link rel="shortcut icon" type="image/x-icon" href="">
<link rel="stylesheet" type="text/css" href="">
<style type="text/css">
*{margin: 0px;padding: 0px;}
.box{width: 100px;height: 100px;border: 1px /*solid double dashed*/ dotted; #ccc ; border-radius: 20px;}
.main{width: 100px;height: 100px;border-top: 1px solid red; background: #ccc;border-left: 1px solid red;border-right: 1px solid red;border-bottom: 1px solid red;}
button{border: none;}
.shadow{width: 300px;height: 40px;box-shadow: 0px 6px 30px $ccc inset;/*border: 1px solid #ccc;*/}
</style>
</head>
<body>
<div class="box"> </div>
<div class="main"></div>
<button>登陆</button>
<div class="shadow"></div>
</body>
</html>
Correcting teacher：天蓬老师Correction time：2019-03-28 10:20:25
Teacher's summary：如果数值为0, 单位是可以省略掉不写的