Hi Jeffrey,
Here is a simple Javascript you may try:
<script>
var footer = document.querySelector('.my-sticky');
window.addEventListener("scroll", function(){
footer.classList.toggle('hide-sticky',
this.innerHeight + this.scrollY >= ((document.scrollingElement.scrollHeight)*9)/10);
});
</script>
Adding this through a Hook Element hooked to wp_footer should work: https://share.getcloudapp.com/QwuLlK4l
Kindly set the display rules as you would prefer.
Then, to make this code work, you would need to add class my-sticky to whichever you want to hide when the scroll reaches around 9/10ths of the screen: https://share.getcloudapp.com/6quZ25Eg
If you wish to hide it at a different position of the screen, kindly replace 9 and 10 to your preferred screen ratio.
Lastly, add this CSS:
.hide-sticky{
display:none !important;
}
Here is an article with regards to adding CSS: https://docs.generatepress.com/article/adding-css/#additional-css
Adding it through additional CSS should work.
For a fade effect, here are some codes you may explore:
https://www.impressivewebs.com/animate-display-block-none/#:~:text=animate%20the%20opacity.-,A%20Possible%20Solution,-There%20are%20probably
re-javascript/#:~:text=The%20fadeOut%20effect%20is%20used,clearInterval%20method%20in%20this%20logic.
Hope this helps! 🙂