How to hide “return to top of page” bar

I love this theme but I don’t like the way the black bar appears and covers content on desktop and mobile. I am hoping there is some css code I can use to hide or remove this “return to top of page” bar. Or, just change it to a small box at the bottom of the screen. As it is now, especially on mobile, it makes it impossible to utilize my site unless you use reader mode, and I don’t expect most people to be patient enough to figure that out before leaving my site. Any and all advice would be much appreciated! I really don’t want to have to change themes just because of this big black bar issue. Thanks in advance! My site is https://www.thefirst-taste.com in case that is helpful to anyone.