This example demonstrates the simplest possible D3.js v6 program: it renders the text “hello word!” in green, centered on a plain white page. The visualization shows how D3’s selection API can directly manipulate the Document Object Model (DOM). The code imports the `select` function from the `d3` module and chains `.text()`, `.style('color')`, and `.style('font-size')` methods to set the text content and CSS styling of the `body` element. No data is loaded; the rendering relies entirely on HTML and inline styles.