.mobile-only {
    display: none;
}

#hi-text {
    margin-bottom: 5rem;
    font-size: 8em;
}

@media (max-width: 730px) { 
    #menu {
        position: static;
    }

    li {
        margin-left: 0px;
        margin-right: 1em;
    }

    .desktop-only {
        display: none !important;
    }

    .mobile-only {
        display: block;
    }
 }