theme.park/CSS/addons/radarr/radarr-4k-logo.css

/* Desktop */
@media (min-width: 752px) {
    .navbar-brand>img {
        display:none !important; 
        }
    .navbar > .container-fluid .navbar-brand:before {
        background-image: url("https://theme-park.dev/CSS/addons/radarr/radarr4k.png");
        display: inline-block;
        width: 128px; 
        height: 128px;
        content:"";
        background-size:  cover;
        -webkit-background-size:  cover;
        -moz-background-size:  cover;
        -o-background-size: cover;
        }
    }
    /* Mobile */
    @media (max-width: 767px) {
    .navbar-brand  .visible-xs img {
        display: none !important;
        } 
    .navbar-brand .visible-xs  {
        display: inline !important;
        }     
    .navbar > .container-fluid .navbar-brand:before {
        background-image: url("https://theme-park.dev/CSS/addons/radarr/radarr4k.png");
        display: inline-block;
        width: 32px; 
        height: 32px;
        content:"";
        background-size:  cover;
        -webkit-background-size:  cover;
        -moz-background-size:  cover;
        -o-background-size: cover;
        margin-bottom: -12px;
        }
    }

/* Radarr V3*/
@media (min-width: 752px) {
    [class*="PageHeader-logoFull-"]  {
        display: none !important;
    }
    [class*="PageHeader-logoContainer-"]:before {
        background-image: url("https://theme-park.dev/CSS/addons/radarr/radarr4k-v3.png");
        display: inline-block;
        width: 148px; 
        height: 48px;
        content:"";
        background-size:  cover;
        -webkit-background-size:  cover;
        -moz-background-size:  cover;
        -o-background-size: cover;
    }    
} 

@media (max-width: 767px) {
    [class*="PageHeader-logo-"]  {
        display: none !important;
    }
    [class*="PageHeader-logoContainer-"]{
        background-image: url("https://theme-park.dev/CSS/addons/radarr/radarr-v3-mobile.png");
        display: inline-block;
        width: 32px; 
        height: 32px;
        content:"";
        background-size:  cover;
        -webkit-background-size:  cover;
        -moz-background-size:  cover;
        -o-background-size: cover;
        margin-left: 20px;
        margin-right: 8px;
        flex: 0 0 32px;
    } 
}