Transparent Scrollbar Track

https://perch-sparrow-5acs.squarespace.com/
password: 12345 

Hi! Is it possible to turn my scrollbar track transparent? I attempted to do it using the code below, but it just turns the scrollbar track white. I would like to make it truly transparent, because as you can see by viewing the site, it cuts off shapes and images. But I have a suspicion it may be not be possible to override this. 

Thank you !!

 ::-webkit-scrollbar-track {
 background: transparent;
}

It does appear to be transparent but there's no content below it, so it shows as white.