Hover Button's Text Gets Masked When Overlay Comes on


Here is the screenshot of the video.

Issue Video

Basically, I want to go from White Background with Green Text to Blue Backgrouod with White Text when the mouse cursor hovers over.
However, for some reason, the overlay comes in and it blocks the whole text or something so I do not see the text ‘Get The Book’ anymore

Here is the read-only link

Here is my public share link: LINK
(how to access public share link)