Let's make a face with D3.js!
This example shows a yellow smiley face drawn in SVG, with eyebrows that animate upward and then return to their original position. The face is constructed through fundamental D3.js DOM manipulation, using `select` and `append` to build circles, rectangles, and a path. The mouth is created with the `d3.arc` generator, while eyebrow movement relies on chained `transition().duration()` calls that modify a `transform` attribute. All shapes are centered within an SVG element sized 960 by 500 pixels.