Why are my base styles are affecting the Drupal administration menu?
Add modifiers to your base styles and apply styles to those to keep them from affecting your Drupal administration menu.
The Drupal administration menu uses your base styles as part of its appearance when viewing the front end of your website. Changes you make to your base styles can sometimes cause your administration menu to inherit these styles.
If you have a base style that is affecting the appearance of your Drupal administration menu, you can circumvent this issue by adding modifiers to override any styles that you don’t want to affect the Drupal administration interface.
An example would be an unordered list base style, with the following modifiers: