盒模型及边框样式
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>盒模型及边框样式</title>
<style>
*{margin:0px;padding: 0px;}
.box{width: 300px;height: 200px; margin: 20px;padding-left:40px;padding-bottom: 30px;
border-top:1px solid red;border-bottom: 3px dashed yellowgreen;}
</style>
</head>
<body>
<div class="box">测试边距</div>
</body>
</html>