Face D3
A yellow circle on a gray SVG canvas represents a simple face. Rendered as a static SVG graphic, the example demonstrates basic D3.js selection and manipulation using `d3.select` and `d3.append`. The circle is centered within a 960 by 500 viewport and styled with a yellow fill via the `.style` method. This minimal visualization highlights core D3 v5 API usage for creating and positioning SVG shapes without any interactive or animated behavior.