embedded url

Something like

.chariti-body a {
    color: red;
    font-family: Arial, sans-serif;
}

added to Additional CSS section of the customizer or style book. This will affect all links on a page though. The read more links do not have a useful attribute to distinguish it from other links. You could insert a distinguishing class attribute through the ‘the_content_more_link’ and ‘excerpt_more’ filters.