A grid of square SVG rectangles demonstrates fundamental vector rendering and CSS interactivity. The 50x50 pixel shapes are positioned manually across a 1000x1000 canvas, creating a structured excavation unit pattern. Hovering a rectangle triggers a CSS transition that fills it with light gray, thickens its stroke to 7 pixels, and changes the border color to red. The example uses raw SVG elements with inline attributes and stylesheet rules rather than JavaScript libraries or data-binding frameworks.