Wordpress: Enqueue CSS for custom post type only

function-enqueue-cpt-css.php

<?php

/**
 * Enqueue specific CSS styles or javascript for a custom post type (cpt).
 */
add_action( 'wp_enqueue_scripts', 'my_cpt_scripts' );
function my_cpt_scripts() {
  if ( is_singular( 'custom_post_type_name' ) || is_post_type_archive( 'custom_post_type_name' ) ) {
    wp_enqueue_style( 'cpt-style', get_stylesheet_directory_uri() . '/css/your-cpt-style.css', false, '', 'all');
  }
}