Reply To: How to edit mobile css in child theme

[Tom]

Since you’re using a child theme hosting on WordPress.org that received updates, not really.

Your other alternative is to create a plugin which adds a stylesheet to the theme.

So your plugin file would have this:

add_action( 'wp_enqueue_scripts', 'yourplugin_scripts', 50 );
function yourplugin_scripts() {

	wp_enqueue_style( 'my-style', plugin_dir_url( __FILE__ ) . 'style.css' );

}

Which assumes you have a style.css file in the same directory as the plugin file.

Adding PHP: https://generatepress.com/knowledgebase/adding-php-functions/