SVG Fundamentals
This example introduces fundamental SVG shapes—a circle, a filled circle, a stroked rectangle, and a line—drawn directly in an inline SVG element with a fixed 960 by 500 viewport. It shows how SVG attributes like `cx`, `cy`, `r`, `fill`, `stroke`, and `stroke-width` control geometry and styling. The code uses no JavaScript libraries, relying purely on raw SVG markup within an HTML page. It demonstrates the basic building blocks for creating vector graphics in the browser.