<style>
    .box {
        width: 100px;
        height: 100px;
        display: inline-block;
        background-color: green;
        margin: 10px;
    }
</style>
<body>
    <div>
        <svg style="position: absolute; top: -999999px" xmlns="http://www.w3.org/2000/svg">
            <filter id="svgDropShadow1">
                <feOffset dx="-20" dy="-20" result="offsetSource"/>
                <feFlood flood-color="black"/>
                <feComposite in2="offsetSource" operator="in"/>
                <feMerge>
                    <feMergeNode/>
                    <feMergeNode in="SourceGraphic"/>
                </feMerge>
            </filter>
        </svg>
        <div class="box" style="filter: url(#svgDropShadow1);"></div>
        <svg style="position: absolute; top: -999999px" xmlns="http://www.w3.org/2000/svg">
            <filter id="svgDropShadow2">
                <feOffset dx="20" dy="-20" result="offsetSource"/>
                <feFlood flood-color="black"/>
                <feComposite in2="offsetSource" operator="in"/>
                <feMerge>
                    <feMergeNode/>
                    <feMergeNode in="SourceGraphic"/>
                </feMerge>
            </filter>
        </svg>
        <div class="box" style="filter: url(#svgDropShadow2);"></div>
    </div>
    <div>
        <svg style="position: absolute; top: -999999px" xmlns="http://www.w3.org/2000/svg">
            <filter id="svgDropShadow3">
                <feOffset dx="-20" dy="20" result="offsetSource"/>
                <feFlood flood-color="black"/>
                <feComposite in2="offsetSource" operator="in"/>
                <feMerge>
                    <feMergeNode/>
                    <feMergeNode in="SourceGraphic"/>
                </feMerge>
            </filter>
        </svg>
        <div class="box" style="filter: url(#svgDropShadow3);"></div>
        <svg style="position: absolute; top: -999999px" xmlns="http://www.w3.org/2000/svg">
            <filter id="svgDropShadow4">
                <feOffset dx="20" dy="20" result="offsetSource"/>
                <feFlood flood-color="black"/>
                <feComposite in2="offsetSource" operator="in"/>
                <feMerge>
                    <feMergeNode/>
                    <feMergeNode in="SourceGraphic"/>
                </feMerge>
            </filter>
        </svg>
        <div class="box" style="filter: url(#svgDropShadow4);"></div>
    </div>
</body>