The sections have negative z-index which means it lies below the “surface”. To edit the text, you can temporarily chance the z-index to 0 or 1. Make sure to change it back if you’re unsure of its function. Just it case it messes with the scrolling effect.
Hm, it didn’t work… But I came up with a work-around:
Created a simple div, copied, the header inside there, removed the header class → only after I removed the header class I was able to edit the copy. Then I re-assigned the header class and moved the header back to where it was…
HOWEVER (!!!) now I can’t move past the scroll-snap-wrapper at all?? Neither in the editor, nor in Preview. All the content is still inside, but just can’t move past it at all?!?.. Help?? Wtf is this even from?