<svg id="svg" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
<g id="g">
<circle cx="50" cy="50" r="25" />
<circle cx="60" cy="60" r="25" />
</g>
</svg>
<style type="text/css">
#svg{width: 500px;height: 500px}
#svg #g{ fill:red; stroke:blue; stroke-width:3;}</style>
