html, body {
    background-color: #fff;
    width: 100%;
    height: 100%;
}
body {
    display: flex;
    align-items: center;
    justify-content: center;
}
@media only screen and (max-width: 600px) {
    .logo {
        width: 95%;
    }
}
@media only screen and (min-width: 600px) {
    .logo {
        width: 80%;
        max-width: 800px;
    }
}