This example illustrates fundamental Scalable Vector Graphics (SVG) concepts using a bare-bones HTML page with embedded CSS and JavaScript. It demonstrates how to create and style basic SVG shapes directly in the browser, using the native `svg` element and its child tags like `rect`, `circle`, and `path`. The code relies solely on standard web APIs and document manipulation, without external libraries. It serves as a minimal starting point for understanding SVG markup and styling, with the rendered output appearing in the main document body.