This example demonstrates the basic building blocks of SVG graphics, including circles, rectangles, a custom path, and a line, all rendered directly on an HTML page. It shows how CSS can animate rectangular elements smoothly over three seconds, and how a hover effect triggers a green fill with a thick stroke. The code uses the native `svg` element and its child tags like `circle`, `rect`, `path`, and `line`, with styling applied via an embedded `<style>` block. It serves as a bare-minimum introduction to SVG fundamentals using only HTML and JavaScript without any external libraries.