font size

You need to add a CSS snippet to do this. Here is an example that changes the font size in the whole of FC, if you want to change the size for specific areas, you have to target them. I've also shown how to change the font. You need to add this with a code snippet plugin.

add_action('fluent_community/portal_head', function() {
    ?>
<style>



/* font ajustments */

@import url('https://fonts.googleapis.com/css2?family=Poppins:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&display=swap');
    body * {
    font-family: "Poppins" !important;  

    /* font-size will ajust the overall font size on the page */
    font-size: 1.0rem !important;
    font-weight: 300;
    }

/* target FC sidebar */
#fluent_community_sidebar_menu {

    padding-top: 2rem !important;
    font-weight: 200 !important;

}

    </style>
    <?php
});