Unable to update tagline size and font on mobile devices

Hello, I need to show the tagline on mobile devices and the code posted on this post works, but I can't change its size and font. This code is not working:

.site-identity {
    display: inline-block !important;
    font-size: 55px !important;
    font-family: Segoe Print !important;
}

How can I customize the tagline font and size? Thanks. Luis