Creating a sub-theme

Creating a sub-theme in Drupal 8 is almost identical to the Drupal 7 process. There are some differences however.

How to build a sub-theme (Zen 7.x-5.x) - Manually

The base Zen theme is designed to be easily extended by its sub-themes. You should Not modify any of the CSS or PHP files in the zen/ folder; but instead you should create a sub-theme of zen which is located in a folder outside of the root zen/ folder.

Subscribe with RSS Subscribe to RSS - sub-theme