This blank slate demonstrates the VizHub V3 runtime’s hot reloading: a single `main` function renders “Hello World” with a fixed font size into a container DIV. Interactive widgets let users Alt-drag the numeric value directly in the editor to update the font size live, with changes reflected instantly alongside `state` and `setState` APIs for immutable state management. The example uses plain HTML and inline CSS for layout, with no external libraries. Its purpose is to show the minimal setup required before building larger visualizations.