This example renders a simple face as a single circle using D3.js v5 and SVG. The code selects the `<svg>` element created in the HTML, reads its width and height attributes, and positions the circle at the exact center with a radius equal to half the height. The page loads D3 from a CDN and imports the `select` function, though the main drawing uses the global `d3.select`. The minimal styling in `styles.css` removes margins and hides overflow while defining a `lines` class that is not currently applied.