Let's make a face with D3.js!
A yellow smiley face is drawn with SVG shapes, and its eyebrows move up and down in a looping animation. The example demonstrates fundamental D3.js v5 DOM manipulation by chaining `transition` and `duration` calls to animate the eyebrow group’s `transform`. It uses `d3.select` to target the SVG, `d3.arc` to create the mouth path, and explicit `attr` setters for circles and rectangles, showing how D3 binds data-less elements to the document.