@media only screen and (max-width: 1920px) {
        body#body-login { background-image: url('https://source.unsplash.com/featured/1920x1080?nature') !important;}
    }
    @media only screen and (min-width: 1921px) and (max-width: 2560px) {
        body#body-login { background-image: url('https://source.unsplash.com/featured/2560x1440?nature') !important;}
    }
    @media only screen and (min-width: 2561px) {
        body#body-login { background-image: url('https://source.unsplash.com/featured/3840x2160?nature') !important;}
    }