const margin = { top: 20, right: 20, bottom: 250, left: 50 };
const previewMargin = { top: 10, right: 10, bottom: 15, left: 30 };
const width = 750 - margin.left - margin.right;
const height = 615 - margin.top - margin.bottom;

const ratio = 4;

const previewWidth = width / ratio;
const previewHeight = height / ratio;