自己的小案例
order-raidus设置边框的圆角 box-shadow:设置边框的阴影 box-shadow:0px 6px 30px #ccc inset; 默认是向外的阴影，如果设置inset则向内的阴影
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>网页头部</title>
<link rel="shortcut icon" type="image/x-icon" href="images/02.jpg">
<link rel="shortcut" type="text/css" href="css/index.css">
<style type="text/css">
.box{width: 100px;height: 100px;border: 1px /*solid double dashed*/ dotted #cccccc;border-radius: 20px; }
.main{width: 100px;height: 100px;border-top: 1px solid red;background: #ccc;border-left: 1px solid red;}
button{border: none}
.shadow{width: 300px;height: 40px;box-shadow: 10px 5px 3px #ccc;border: 1px}
</style>
</head>
<body>
<div class="box"></div>
<div class="main"></div>
<button>登录</button>
<div class="shadow"></div>
</body>
</html>