Hover on button text disappears

Ok so i figured out what is causing it and i need to know how to fix it. my theme “default link hover color” is the same as the background of the button so it’s not “removing it” it is just using the same color and making it hidden because of that. What and where do i put css for making the link hover color “white” instead of theme default?

I have changed the color of the button temporarily until you can help me with the css to change link color on hover for this plugin.