Fork of Let's make a face with D3.js!
This example demonstrates basic DOM manipulation with D3.js by constructing a smiley face from SVG circles, rectangles, and an arc path. The face’s eyebrows animate up and down in a repeating two-second cycle using chained `transition().duration()` calls. Built with D3 v5, the code uses `select`, `arc`, and attribute setters to position facial features relative to the SVG center. The data is hardcoded via numeric constants for spacing and dimensions, and the animation runs continuously on page load.