Zoom Hero
X-ray · layers
Parameters
How this effect works
The hero starts slightly too big — scaled to the zoom from value — and eases down to its natural size as you scroll through the zoom span portion of the track. Because scale is a compositor transform, the browser animates it without repainting a single pixel. Starting oversized and settling to 1 (rather than 1 shrinking to 0.8) is the professional detail: the resting state of your page is pixel-perfect, and the "zoom" is only ever a departure from it.
Dim ties brightness to the same progress — receding things lose light — and counter-move pushes the title up faster than the visual shrinks. That disagreement between foreground and background speeds is the same trick as parallax: two things moving differently is what your brain accepts as 3D. All three read the one scroll progress number; none of them keep any state.