D3 JS Face!
A smiley face rendered in SVG animates its eyebrows in a sequence of timed transitions. The face is drawn with D3.js primitives: a yellow circle for the head, two circles for eyes, rectangles for eyebrows, and a path generated with the `d3.arc` function for the mouth. The animation uses D3’s `.transition().duration()` to move the eyebrows up, hold, and return, demonstrating fundamental DOM manipulation with `d3.select` and element creation.