问题 I am trying to use CSS variables in an Angular project together with Sass functions ( lighten() / darken() to be precise), and as far as I know, the latest version of LibSass allows it. I have installed node-sass@4.11.0 and sass-loader@7.1.0 (and on Angular v7.3.0), but yet I receive an error Argument $color of lighten($color, $amount) must be a color Am I missing something? Thanks! 回答1: Unfortunately you can't... lighten is a SASS function at compile-time, while CSS variables are run-time