body {
    margin: 0;
    padding:0;
}

main {
    width: 100%;
    height: 100%;
    position: absolute;
    display: block;
    text-align: center;
}

.logo-center {
    text-align:center;
    position: relative;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    transform:translate(-50%,-50%);
    img {
        max-width:300px;
        height:auto;
    }
}

@media screen and (max-width:480px) {
    .logo-center {
        img {
            max-width:220px;
            height:auto;
        }
    }
}