This example demonstrates the simplest possible integration of JavaScript and CSS within an HTML page, rendering a static “Hello HTML!” message centered on the screen. The styling uses a CSS class with a large font size, while the page loads D3 v7 from a CDN but does not invoke any of its visualization functions. A separate JavaScript file imports a `selection` object from D3, yet only logs a string to the console, highlighting the minimal setup for a D3-powered project.