body {
    margin: 0;
    overflow: hidden;
}

body.black {
    background: #000;
}

.logo {
    display:flex;
    width: 100vw;
    height: 100vh;
    background-image: url(/images/1.png);
    background-repeat: no-repeat;
    background-size: auto 75%;
    background-position: center;
}

body.black .logo {
    background-image: url(/images/2.png);

}

@media only screen and (max-width: 600px) {
    .logo {
        background-size: 75% auto;
    }
}