For Sass, yes[0] --- as has Hugo[1]. Hugo's recently added `css.Build` function, based on esbuild, is for post-processing vanilla CSS.<p>[0]: <a href="https://www.getzola.org/documentation/content/sass/" rel="nofollow">https://www.getzola.org/documentation/content/sass/</a><p>[1]: <a href="https://github.com/gohugoio/hugo/releases/tag/v0.43" rel="nofollow">https://github.com/gohugoio/hugo/releases/tag/v0.43</a> (July, 2018)