This example demonstrates how to construct and style geometric shapes using Scalable Vector Graphics (SVG) elements embedded directly in an HTML document, with CSS controlling their visual properties such as color and size. The code uses the HTML5 DOM structure and a linked stylesheet to define a highlighted class that changes text color to red. The page includes a body element for content and references separate JavaScript files, though no interactive data visualization or dynamic rendering is implemented in the provided files. The example focuses on fundamental markup and styling techniques rather than data-driven charting.