This example demonstrates how D3.js can manipulate SVG elements to create an animated smiley face with moving eyebrows. The code selects an `<svg>` element and uses D3’s data-binding and attribute methods to position facial features, while the eyebrow movement relies on D3 transitions. It renders entirely in-browser using D3 v5, with no external data source—the face is built from static shapes defined in `index.js`. The visual result is a playful, interactive-looking illustration of core D3 DOM manipulation techniques.