This example displays a single red circle rendered inside an SVG canvas. It serves as a minimal setup for SVG-based visualization, showing how a static shape can be styled directly using D3. The code uses D3 v5's selection and styling API (`d3.select` and `.style`) to apply the fill color, while the circle itself is defined in plain SVG markup within the `index.html` file. The page also imports a separate stylesheet for global typography and layout.