This example renders a full-page message reading “Hello HTML!” using pure HTML and CSS, with a class-based style rule that centers the text and sets its font size to 13em. The page contains no JavaScript logic or data loading, relying solely on a static `<div>` element styled by the `<style>` block. It demonstrates a minimal, standalone implementation of CSS layout and typography without external libraries or frameworks, serving as a bare-bones starting point for browser-based visualizations.