This example demonstrates how basic SVG shapes—circles and rectangles—can be styled using CSS. It shows three shapes on an SVG canvas: two circles and a rectangle, with the second circle explicitly filled red via an attribute. The code uses plain SVG markup within an HTML page, linked to an external stylesheet. The stylesheet defines a highlighted class with a red text color, although no elements in the markup currently apply this class, and sets the body margin to zero with hidden overflow. No JavaScript or additional libraries are involved.