SVG Fundamentals
This example demonstrates fundamental SVG shapes—two circles and a rectangle—rendered directly on an HTML page. The first circle appears with default black fill, while the second is explicitly colored red, and the rectangle uses a blue stroke with no fill. The code uses plain SVG elements (`circle`, `rect`) within an inline `<svg>` tag, with styling attributes like `fill` and `stroke-width`. No JavaScript or external libraries are involved; the visualization relies solely on static SVG markup and CSS-like presentation attributes.