This example demonstrates how D3.js can integrate with modern JavaScript modules to create a basic interactive web page. It loads D3 v5 from a CDN and uses ES6 imports to bring in both the `select` function from D3 and a custom message from a local module. The code sets the text of a div element to display a greeting, and also defines a numeric constant and a regular expression to showcase additional JavaScript syntax. The example serves as a minimal template for combining D3 with modular code structure.