A full-window SVG renders a single circle that fills the viewport with a smooth transition from gold at the center to red at the edge. The visualization uses a `<radialGradient>` defined in the SVG `<defs>` section, with two `<stop>` elements specifying color and offset percentages. The circle references this gradient via the `fill` attribute using `url('#myGradient')`. This example is adapted from MDN documentation and demonstrates core SVG gradient functionality without any JavaScript or data processing.