CSS

PostCSS

Each design module defines a directory where Hugo looks for postcss.config.js. This value is set in the theme’s own hugo.yaml, you don’t need to override it in your project params:

# Set by the theme (e.g. hugolify-theme-bootstrap/hugo.yaml)
css:
  postcss: "postcss/bootstrap"       # hugolify-theme-bootstrap

The config file must exist at that path in your project (e.g. postcss/bootstrap/postcss.config.js). Each theme ships an example you can copy. If no directory is set, Hugo falls back to postcss.config.js at the project root.

Preload CSS

css:
  preload: true   # adds <link rel="preload"> for performance

Print CSS

css:
  print: true     # loads sass/print.sass or css/print.css with media="print"