How Can I Set Banner to Lock intrinsic size on homepage - desktop and mobile

I have this image that I want to have displayed at the full size without getting cropped by the CSS embedded in the code on both desktop and mobile. How can I do that using the Custom CSS?

I know you're not supposed to use embedded text in banners, but that's besides the fact. This theme doesn't have enough font styling to achieve this result without it. 

site URL: https://dcbhs.com/

@tuanphan How about getting the image to display at full width on desktop as well. At the moment, squarespace crops it.

Which screen sizes do you see problems? It looks fine to me

@tuanphan see how it gets clipped at the larger screen sizes on the top and bottom? this is at 2560x1440 and 1920x1080

Try this CSS code

@media screen and (min-width:1800px) {
body.homepage .banner-thumbnail-wrapper {
    min-height: 300px;
}
}