css.css

a:not([href*="//"]) {
    /* CSS for internal links */
}

a.md-footer-social__link.fa.fa-globe {
    !background: none;
}

a[href*="//"]:not( [href*='gitlab.it4i.cz'] ):not( [href*='code.it4i.cz'] ):not( [href*='https://www.it4i.cz'] )  {
    /*CSS for external links */
    background: transparent url("/img/external.png") no-repeat right 0px top 1px;
    background-size: 12px;
    padding: 1px 16px 1px 0px;
}