Four SVG shapes—two circles and two rectangles—demonstrate presentational attributes and CSS styling. The first pair uses default black fill, while the second pair applies inline `fill` colors. A `<g>` group with `transform`, `fill`, `stroke`, and `stroke-width` attributes applies shared styling to both a circle and rectangle, showing inheritance and grouping in SVG. The example uses no JavaScript libraries, relying purely on SVG markup and external CSS from `styles.css`. The `styles.css` file defines global body margins but contains unused `.lines` rules, leaving shape styling entirely attribute-driven.