SVG Fundamentals
This example demonstrates fundamental SVG shapes rendered directly in a web page using React. It draws a pair of circles with different radii and fills, a yellow rectangle with a navy stroke and thick border, and a black polyline path defined by multiple coordinate points. The SVG container is set to 960 by 500 pixels, and all elements are positioned using explicit `x`, `y`, `cx`, `cy`, and `r` attributes. The code uses basic SVG APIs such as `circle`, `rect`, and `path` elements without any external visualization libraries.