can i stop view or scroll timeline animation when scrolling up?

Question

i am learning css timeline animations with view() and scroll(). it all works great but one issue: unlike when using javascript observation intersection, i cannot seem to stop the animation while scrolling up. so for example is i have this code:

.do-fade{
animation: fade-in 350ms linear forwards;
animation-timeline: view(block);
animation-range: 100px 300px;
}

@keyframes fade-in{
 from{opacity:0}
 to{opacity:1}
}

the fade-in animation will be implemented both on the way down and up. what is i want it to only be implemented when scrolling down a page?