<!DOCTYPE html>

<html>
<head>
    <style>
        .filtered {
            overflow: hidden;
            margin: 40px;
            padding: 20px;
            height: 200px;
            width: 200px;
            background-color: silver;
            border: 1px solid black;
            filter: blur(1px);
            box-shadow: 0 0 20px black;
        }

        .contents {
            width: 100%;
            height: 200%;
            background-image: repeating-linear-gradient(blue, blue 50px, green 50px, green 100px);
        }
    </style>
</head>
<body>
    <div class="filtered">
        <div class="contents"></div>
    </div>
</body>
</html>