SVG fundamentals
This example shows a minimal SVG scene with three nested circles positioned along a diagonal, demonstrating fundamental vector graphics rendering. The layout places a large black circle, a smaller red circle, and a tiny green circle, each with increasing center coordinates. The code uses raw SVG elements (`circle`, `cx`, `cy`, `r`, `fill`) directly in an HTML page, with no external libraries or JavaScript logic. It illustrates how static shapes are defined declaratively and rendered by the browser, serving as a basic starting point for data-driven visualizations.