This example demonstrates a minimal setup for embedding D3.js within an HTML page using inline SVG. The page displays the text "Hello HTML" and a gray SVG background, created by initially rendering an empty `<svg>` element and then styling it via D3's `select` method. The code directly loads the D3 v5 library from a CDN and uses standard JavaScript to manipulate the SVG, illustrating a bare-bones starting point for D3 projects without external frameworks like React.