Fork of Let's make a face with D3.js!
A yellow face built from D3.js SVG shapes animates its eyebrows in a looping motion. The example constructs a circle for the head, two circles for eyes, and a path generated with `d3.arc()` for the mouth, all centered via an SVG group. Eyebrow rectangles transition vertically using chained `transition().duration()` calls on a group containing them, moving down and back up over two seconds per phase. The code imports `select` and `arc` from the D3 v5 library, and renders the illustration on a 960×500 SVG canvas.