This example demonstrates a minimal web page that combines HTML, CSS, and JavaScript with canvas rendering. It displays a large “Hello HTML!” message while also drawing a red rectangle and a series of horizontal grid lines on a canvas element using the Canvas 2D API. A separate “Hello world!” text is injected into a div via `document.getElementById` and `textContent`. The source code uses vanilla JavaScript with no external libraries, showing basic canvas drawing commands like `fillRect` and `stroke`.