This example displays a simple text message, “Hello world,” on a dark blue page with a large Ubuntu font. It demonstrates a minimal D3.js v5 setup, using the `select` function to target a DOM element and setting its text content. The page loads D3 from a CDN and bundles local ES6 modules, with the message string imported from a separate `myMessage.js` file. The styling is applied through an external stylesheet that defines the body’s colors and font family.