Let's make a face
A simple SVG face is drawn with D3 v7, composed of a yellow circular head, two black eyes, and a mouth. The code uses D3 selections and the `arc` generator to create the mouth path, while circles are positioned relative to the SVG's width and height. The example demonstrates common SVG attributes like `cx`, `cy`, `r`, `fill`, and `stroke`, rendered directly to the SVG canvas in a fixed 960x500 viewport.