title: Modifying Drupal 8 administration theme
body: <p>I've recently added the faqfield module - but when reviewing this in the content editor the fields are spewing over the container.</p>
  
  <p>I fixed the issue by adjusting the textarea.form-textarea css to min-width:100% in chrome console -- but I am not sure how to apply this fix to the site itself. Is there a way of adding into the db level an override css for the admin theme? Or do I create an overriding change in the theme folder - and if so how?</p>
  
  <p>before quick fix
  <a href="https://i.stack.imgur.com/cpiXC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cpiXC.png" alt="enter image description here"></a></p>
  
  <p>after quick fix
  <a href="https://i.stack.imgur.com/c55LX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/c55LX.png" alt="enter image description here"></a></p>