wp_enqueue_scripts and CSS

You can set the priority in hook. Priority is the 3rd parameter in the hook. In the following example, wp_enqueue_scripts will have priority of 99 which is higher than normal priority. Default priority is 10. So it will load at last

function load_last_style() {
    wp_enqueue_style( 'style-name', get_stylesheet_uri() );
}

add_action( 'wp_enqueue_scripts', 'load_last_style', 99 );