D3.js Training
This example demonstrates the VizHub V3 runtime environment’s “Hello World” starting point, rendering a centered text message directly into a DOM container. The `main` function sets `container.innerHTML` with a styled `div`, using a fixed `fontSize` value that can be interactively adjusted via Alt-drag in the editor. No external visualization libraries are used; the code relies solely on vanilla JavaScript and inline CSS to display the text “D3 training FreeCodeCamp.org”.