This image shows the Additional CSS feature in WordPress. I’m trying to find the file that stores the additional CSS, but can’t seem to find it anywhere – I’ve searched almost every folder in wp-content!
Does anyone know how Additional CSS for the theme is stored and, if it is in a file, where this file is located!
It’s stored in the database, within the wp_posts table, under the custom_css post type, where the post name is the theme slug. There you also have the related customize_changeset and revision post types.
The custom css post ID is also stored in the wp_options table under each theme mods, e.g. theme_mods_twentysixteen for Twenty Sixteen.
It’s informative to check out how the custom CSS fetched from the database with:
wp_get_custom_css() that uses wp_get_custom_css_post()
and displayed through the wp_head action with:
wp_custom_css_cb()