Hugo publishes assets to the publishDir (typically public ) when you invoke .Permalink , .RelPermalink , or .Publish . You can use .Content to inline the asset.
—— Hugo Pipes | Hugo
In your approach, you’ll need to publish each CSS as you did for styles/index.css.
The CSS import statement, in this context, doesn’t do what you think it does.
If you want to “compile” all files into one, you can do either of:
Remove the import statements and use the resources.Concat template function
Create a main.scss file, using either @import or @use (depending on the transpiler), then transpile the Sass to CSS using the resources.ToCSS template function