This example demonstrates the JavaScript module system for importing and exporting variables between files. It shows how to share constants (`aThing`, `someThing`) across script files and how to load D3’s `select` API. The page renders a static HTML message with an inline `<style>` rule for large centered text, then logs imported values and the D3 `select` object to the console. It uses `d3.v7` from a CDN and relies on the browser’s native ES module support.