<style>
    .filtered {
        position: absolute;
        width: 100px;
        height: 100px;
        margin: 50px;
        border: none;
        background-color: lime;
        filter: url('#filter');
    }
    .bordered {
        position: absolute;
        width: 120px;
        height: 120px;
        margin: 30px;
        border:10px solid black;
        background-color: none;
    }
</style>
<body>
    <div class="filtered"></div>
    <div class="bordered"></div>
    <svg width="0" height="0">
        <filter id="filter" primitiveUnits="userSpaceOnUse">
            <feMorphology operator="dilate" radius="50"/>
        </filter>
    </svg>
</body>
