html, body
{
    height: 100%;
    margin:0;
    padding:0;
}

div {
    position:relative;
    height: 100%;
    width:100%;
}

div img {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

div a {
    position: absolute;
    top: 90%;
    left: 50%;
    transform: translate(-50%, 0);
    font-size: 40px;
}