CSS to change hover color of button on header menu 7.1

Site URL: https://www.sitbelove.org/

Hello, Im having trouble getting the code to work to change the hover state of the header button on 7.1 

I have already added this css to change color: 

/*nav contact button color*/

.header-actions .btn 
{color: #fff !important;
border-color: #fff !important;
background-color: #304A55 !important;
}

Ive tried to add this to make the hover state change but im not sure how to write the code: .header-actions .hover

or, how i wrote it is not working.. Thoughts? The goal is to change the hover state to a different color OR to transparent outline. Thanks so much!! 

Password [buddha]

Try this code 

.header-actions .btn:hover {background:#fff!important;}

Thanks Nabioh, it worked! 

/*nav contact button color hover*/
.header-actions .btn:hover {background:rgba(255, 255, 255, 0.5)!important;
border-color: #000 !important;
 border-width: 2px !important;
color: #000 !important;}