Fork of Let's make a face with D3.js!
This example demonstrates fundamental DOM manipulation with D3.js by drawing a smiley face with yellow circular head, eyes, eyebrows, and an arc-based mouth. The animation shows the eyebrows moving up and down repeatedly, using D3's transition system to create a two-second duration tween between transform states. The code imports `select` and `arc` from the D3 library, builds SVG shapes through chained `.attr()` calls, and relies on `d3.v5` with SVG rendering.