docs: function buildStyles(conf, undertaker) {
  
      // Config that gets passed to node-sass.
      const sassConfig = conf.themeConfig.sass.nodeSassConf || {};
  
      // If we're in production mode, then compress the output CSS.
      if (conf.productionMode) {
        sassConfig.outputStyle = 'compressed';
      }
  
      // Any PostCSS conf and settings.
      const postCSSConf = [
        autoprefixer({
          browsers: conf.themeConfig.sass.browserSupport || 'last 2 versions'
        })
      ];
  
      const sassSrc = path.join(conf.themeConfig.root, conf.themeConfig.sass.src, '**', '*.scss');
      const sassDest = path.join(conf.themeConfig.root, conf.themeConfig.sass.dest);
  
      // The task itself.
      return undertaker.src(sassSrc)
        .pipe(gulpIf(!conf.productionMode, sourcemaps.init()))
        .pipe(sass(sassConfig).on('error', sass.logError))
        .pipe(postcss(postCSSConf))
        .pipe(gulpIf(!conf.productionMode, sourcemaps.write('.')))
        .pipe(undertaker.dest(sassDest));
  
  }