This example demonstrates basic SVG shapes—circles and rectangles—styled directly with CSS and inline attributes. It shows how shape properties like position, size, fill color, stroke, and grouping via the `<g>` element affect rendering. The visualization uses raw SVG markup within an HTML page, with external styling from `styles.css`. A grouped set of shapes applies a shared fill color and stroke, while individual shapes use explicit `fill` values such as red and hex codes. No JavaScript libraries are involved; rendering is purely declarative SVG.