Smiley Face with D3.js
This example draws a yellow smiley face in an SVG element using D3.js v5. The face consists of a large circle for the head, two smaller circles for eyes, and a mouth created with the d3.arc generator. The code imports `select` and `arc` from the D3 module to manipulate the SVG and construct the curved mouth path. Elements are positioned relative to the center of the SVG using translation transforms, with fixed pixel offsets for eye spacing and mouth placement.