canvas.processing {
    width: 600px;
    height: 400px;
    margin: 0 auto;
    display: block;
    box-shadow: 0 0 1.5px 1.5px rgba(0, 0, 0, 0.25);
}

canvas.processing {
    width: 600px;
    height: 400px;
    margin: 2em auto;
    display: block;
    box-shadow: 0 0 1.5px 1.5px rgba(0, 0, 0, 0.25);
}

Add margin to Processing canvases
Add margin to Processing canvases
