This example visualizes a sunrise and sunset pattern as a 500-by-500 pixel square using D3.js’s built-in shapes. It renders a single visual root element via the `select`, `selectAll`, `range`, and `scale` functions from the D3 v7.6.1 library, drawing geometric forms that represent the day-night cycle. The code relies on a simple HTML container with linked CSS, and the graphic is generated entirely on a blank canvas without external data files.