Customizr Pro Slider Button Color

I’m attempting to adjust the color of the buttons on the Slider for my website https://www.fsc-homes.com

I was able to change the button color to the code that is listed below, but when I hover over the button, the color slides up and creates a half color/half grayish white division. Any tips? This is the code that I plugged into the CSS editor.

.btn-primary {
background-color: #590000;
background-image: linear-gradient(to bottom, #590000, #590000);
width:200px;height:200px
color: white;
font-family:Arial;
}