Let's make a face with D3.js!
A yellow smiley face is drawn in SVG, with its eyebrows animated to move up and down in a continuous loop. The example demonstrates basic DOM manipulation with D3.js, using `d3.select` and `d3.append` to build the face from circles, rectangles, and a path, then applying `transition().duration()` to animate the eyebrow movement. The mouth is created using the `d3.arc` shape generator, and the entire scene is centered within an SVG canvas of fixed dimensions.