A new version of the D3 logo with a high-contrast outline. This was designed for the official D3 sticker, which is available for only $4.
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
background: #fcfcfa;
}
</style>
<svg width="960" height="500" viewBox="-20 -20 136 131">
<defs>
<path id="deethree" d="M0,0h7.75a45.5,45.5 0 1 1 0,91h-7.75v-20h7.75a25.5,25.5 0 1 0 0,-51h-7.75zM36.2510,0h32a27.75,27.75 0 0 1 21.331,45.5a27.75,27.75 0 0 1 -21.331,45.5h-32a53.6895,53.6895 0 0 0 18.7464,-20h13.2526a7.75,7.75 0 1 0 0,-15.5h-7.75a53.6895,53.6895 0 0 0 0,-20h7.75a7.75,7.75 0 1 0 0,-15.5h-13.2526a53.6895,53.6895 0 0 0 -18.7464,-20z"/>
</defs>
<use xlink:href="#deethree" stroke="black" stroke-width="20"/>
<use xlink:href="#deethree" fill="white"/>
</svg>