This example demonstrates how SVG shapes can be styled and manipulated using CSS. The page is intentionally minimal, with an empty `<body>` element and a linked stylesheet that defines visual properties for graphical elements. The CSS applies a red highlight class, black stroke styles for line elements, and blue strokes with rounded joins for paths within a lines class. The SVG and CSS rules show how strokes, colors, and line joins can be controlled declaratively, though no actual shapes are rendered in the provided HTML.