<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
</head>
<body>
<svg viewBox="0 0 30 10" xmlns="http://www.w3.org/2000/svg">
<defs>
<filter id="shadow">
<feDropShadow dx="0.2" dy="0.4" stdDeviation="0.2" flood-color="blue" />
</filter>
<filter id="shadow2">
<feDropShadow dx="0" dy="0" stdDeviation="0.5" flood-color="green" />
</filter>
</defs>
<circle cx="5" cy="50%" r="4" style="fill:lightgrey; filter:url(#shadow);" />
<circle cx="15" cy="50%" r="4" style="fill:lightgrey; filter:url(#shadow2);" />
</svg>
</body>
</html>