This example shows a bare-bones React and D3.js starter template that renders a blank SVG visualization area. The `VizContainer` component abstracts the SVG and group elements, implementing D3’s margin convention with configurable outer and inner rectangles in gray and light gray to visualize the layout. The code uses React 16, ReactDOM, and D3 v6 loaded via CDN, with fixed dimensions of 960×500 pixels. The optional `showMargins` prop toggles the display of these guide rectangles, which can be removed for production use by deleting the prop from the call.