seo_starter_kit-8.x-1.0-alpha2/modules/seo_starter_kit_common/seo_starter_kit_common.module

<?php

/**
 * @file
 * Remove files.
 */

/**
 * Remove core css files.
 *
 * @see tao_css_alter()
 */
function seo_starter_kit_common_css_alter(&$css) {
  $is_admin = \Drupal::service('router.admin_context')->isAdminRoute();
  if (!($is_admin)) {
    $exclude = [
      'core/misc/vertical-tabs.css' => FALSE,
      'core/misc/print.css' => FALSE,
      'core/modules/dblog/css/dblog.module.css' => FALSE,
      'core/modules/filter/css/filter.admin.css' => FALSE,
      'core/modules/filter/css/filter.caption.css' => FALSE,
      'core/modules/menu_ui/css/menu_ui.admin.css' => FALSE,
      'core/modules/node/css/node.admin.css' => FALSE,
      'core/modules/node/css/node.module.css' => FALSE,
      'core/modules/node/css/node.preview.css' => FALSE,
      'core/modules/system/css/system.admin.css' => FALSE,
      'core/modules/system/css/system.diff.css' => FALSE,
      'core/modules/system/css/system.maintenance.css' => FALSE,
      'core/modules/system/css/components/ajax-progress.module.css' => FALSE,
      'core/modules/system/css/components/align.module.css' => FALSE,
      'core/modules/system/css/components/autocomplete-loading.module.css' => FALSE,
      'core/modules/system/css/components/clearfix.module.css' => FALSE,
      'core/modules/system/css/components/container-inline.module.css' => FALSE,
      'core/modules/system/css/components/details.module.css' => FALSE,
      'core/modules/system/css/components/fieldgroup.module.css' => FALSE,
      'core/modules/system/css/components/hidden.module.css' => FALSE,
      'core/modules/system/css/components/item-list.module.css' => FALSE,
      'core/modules/system/css/components/js.module.css' => FALSE,
      'core/modules/system/css/components/nowrap.module.css' => FALSE,
      'core/modules/system/css/components/position-container.module.css' => FALSE,
      'core/modules/system/css/components/progress.module.css' => FALSE,
      'core/modules/system/css/components/reset-appearance.module.css' => FALSE,
      'core/modules/system/css/components/resize.module.css' => FALSE,
      'core/modules/system/css/components/sticky-header.module.css' => FALSE,
      'core/modules/system/css/components/tabledrag.module.css' => FALSE,
      'core/modules/system/css/components/tablesort.module.css' => FALSE,
      'core/modules/system/css/components/tree-child.module.css' => FALSE,
      'core/modules/taxonomy/css/taxonomy.theme.css' => FALSE,
      'core/modules/tour/css/tour.module.css' => FALSE,
      'core/modules/update/css/update.admin.theme.css' => FALSE,
      'core/modules/user/css/user.admin.css' => FALSE,
      'core/modules/user/css/user.icons.admin.css' => FALSE,
      'core/modules/user/css/user.module.css' => FALSE,
    ];
    $css = array_diff_key($css, $exclude);
  }
}