padding margin

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="utf-8">
    <style>
        .a {
            width: 100px;
            height: 100px;
            padding: 20px;
            margin: 50px;
            background-color:#FFF;
            border:inset 10px #0000ff;
            border-radius:10px;
        }
    </style>
</head>
<body>
    <div class="a">foo</div>
</body>
</html>

f:id:hrt0kmt:20140712144729p:plain