header h1 {
    margin-top: 2em;
    margin-bottom: 2em;
    text-align: center;
    font-family: Helvetica;
    color: gray;
}

main svg {
    display: block;
    margin-top: -12em;
    margin-right: auto;
    margin-left: auto;
    width: 80%;
}

footer p {
    text-align: center;
}