Offset from an edge relative to the other edge of the container

[y1n0]

Hello, everyone.
How can we achieve something like <Waypoint bottomOffset="calc(100% - 50px)"} />

I wanna be able to combine that with topOffset={50} so that Waypoint will fire each time an element (passed to Waypoint as children) crosses that line from either direction

[trotzig]

For this type of fine-control behavior I would probably look into using IntersectionObserver.