add_action('wp_enqueue_scripts', 'cyb_scripts');
function cyb_scripts() {

    // Enqueue only for registration page
    if( is_page( 'registration' ) ) {

        wp_enqueue_style( '...' );

    }

}

add_action('wp_enqueue_scripts', 'cyb_scripts');
function cyb_scripts() {

    // Enqueue only for registration page
    if( is_page_template( 'page-registration.php' ) ) {

        wp_enqueue_style( '...' );

    }

}