This example displays the text “Hello HTML!” centered on a plain white page. The message is styled using a CSS rule that sets the font size to 13em and aligns the text to the center of the viewport. The implementation relies on a single `index.html` file that combines embedded `<style>` and `</style>` tags with standard HTML markup. No JavaScript libraries or data sources are used; the page is a minimal demonstration of basic HTML and CSS for static visual output.