Shapes and Colors with SVG and CSS
This example demonstrates basic SVG rendering with D3, showing a red background applied to an SVG canvas. The code selects the `svg` element using `d3.select` and sets its background color through the style method, while the body has hidden overflow and no margin. It includes a static SVG container sized at 960 by 500 pixels, with a linked stylesheet for CSS styling. The example uses D3 v5 and the SVG rendering approach, serving as a minimal introduction to combining SVG elements with D3 selections and CSS for visual customization.