One of the most common questions in our training is how to add custom CSS or Javascript to a Drupal site.
The best solution, of course, is to add it to the theme (preferably a sub-theme); however many times site builders and editors don't have access to the codebase of a Drupal site.
To accomplish this, you can use the Asset Injector module. This module combines CSS Injector and JS Injector from Drupal 7 into one.
Let's get started...