By tying a mathematical CSS clip-path radius directly to the viewport's vertical scroll progression, we forge a deeply physical connection between the user's action and the digital canvas.
A 400vh tall wrapper intercepts the scroll event, while the sticky inner `h-screen` viewport renders the frames over an extended distance.
Framer motion smoothly maps the `[0, 1]` scroll progress to a `circle(X% at 50% 50%)` radius, driving the explosive geometry.
The inner video subtly scales down (`1.1` to `1.0`) as the outer mask expands, creating an optical illusion of pushing a lens deeper into the frame.