This example demonstrates basic D3.js setup and ES6 module usage within a VizHub template. It loads D3 v5 from UNPKG and uses the `select` function from the `"d3"` import to update the text content of a `#message` div with a string exported from a local module. The page renders a large, centered “Hello VizHub!” message styled via CSS, showing how to combine external libraries, local imports, and styles in a single visualization harness.