.space {
    height: 3rem;
    background-color: rgba(0, 0, 0, .1);
    border: solid rgba(0, 0, 0, .15);
    border-width: 1px 0;
    box-shadow: inset 0 0.5em 1.5em rgb(0 0 0 / 10%), inset 0 0.125em 0.5em rgb(0 0 0 / 15%);
}

.fa-bootstrap, .fa-twitter, .fa-instagram, .fa-facebook {
    font-size: 32px
}