body {
    height: 100dvh;
    display: grid;
    place-items: center;
    grid-template-rows: 1fr auto;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

main {
    color: white;
}

main img {
    position: absolute;
    transform: translate(-50%, -50%);
    z-index: -1;
    top: 50%;
    left: 50%;
}