I created this effect to help someone out on the Webflow Discord, and I thought I'd make it cloneable in case anyone else wants to use it! I also decided to spice it up a little with some lovely animations from Lottieflow :) The basic effect is achieved just by setting the header as fixed at a lower z-index than the (relative positioned) content below.

clonable, header, overlap, overlapped, hidden, animation, lottieflow, lottie, interaction, scroll, scrolleffect, scrolleffects, cover