body {
    display: flex;
    min-height: 100vh;
    flex-direction: column;
}

main {
    flex: 1 0 auto;
}

.promo i {
    margin: 40px 0;
    font-size: 7rem;
    display: block;
}

.promo-caption {
    font-size: 1.7rem;
    font-weight: 500;
    margin-top: 5px;
    margin-bottom: 0;
}