This interactive fractal displays a Sierpinski triangle that divides into recursively smaller subtriangles on an HTML5 Canvas. The branching depth changes dynamically based on mouse position, ranging from zero to ten subdivisions. The code uses the Canvas API’s `getContext` and `fill` methods, with `devicePixelRatio` to ensure sharp rendering on high-resolution displays. Moving the mouse horizontally triggers a `mousemove` event, recalculating depth and redrawing the triangle with `clearRect` and recursive function calls.