This example demonstrates basic SVG shapes embedded directly in an HTML document without any JavaScript libraries. It shows circles, rectangles, and a line rendered as SVG elements, with some shapes using default black fills while others specify explicit fill colors like red and green. A `<g>` group element applies a shared fill color, stroke color, and stroke width to multiple shapes, and the `transform` attribute translates the group’s position. The page also includes a simple CSS rule that removes the body margin and hides overflow, while an unused `.lines` class suggests styling for potential path elements.