One hundred circles, each filled with a red-to-blue linear gradient, animate randomly across a black SVG canvas over five seconds. The visualization demonstrates basic D3 v6 selection, data binding, and transition methods, using `d3.select` to append an SVG and `transition().duration()` to move each circle’s `cx` and `cy` attributes. The circles, with a radius of 20 and 80% opacity, also receive a gradient stroke via the `url(#svgGradient)` reference. No external data is involved; positions are generated from `Math.random()` multiplied by each index.