Fork of Let's make a face with D3.js!
A D3.js v5 smiley face is drawn with SVG primitives, including a yellow circle, two black eyes, and an arc-based mouth. The eyebrows are rectangles that animate upward and back down using chained `transition.attr` calls over two seconds each, demonstrating fundamental DOM manipulation. All shapes are appended to a central group translated to the SVG’s center, with coordinates computed from the viewport’s width and height.