Extending themes

A theme can extend another theme using the extends key.

If the value is default, it resolves to the built-in default theme. Otherwise the value of extends is a relative path from the current theme file to the theme being extended. If a theme doesn't have an extends key, default PDF2 plug-in styles are used.

base.yaml

brand:
  primary-color: orange
page:
  size: A4

product/theme.yaml

extends: ../base.yaml
page:
  size: Letter
style:
  topic:
    color: $brand-primary-color