This example displays the text “Hello D3” at a massive 14em font size, centered on the page. It demonstrates the simplest possible D3 setup, where the index.html file loads D3 v7 via an import map and the index.js module uses the `select` function to target the body element. The code then calls the `.text()` method to replace the page content with the greeting. It serves as a minimal starter template, highlighting basic DOM manipulation with the d3-selection API and modern ES module imports.