ezcontent-8.x-dev/modules/ezcontent_paragraphs/modules/ezcontent_card_list/ezcontent_card_list.module

<?php

/**
 * @file
 * Module file for ezcontent_demo.
 */

/**
 * Implements hook_preprocess_HOOK().
 */
function ezcontent_card_list_preprocess_paragraph__card_list(&$variables) {
  $variables['#attached']['library'][] = 'ezcontent_card_list/ezcontent_card_list_css';
}