SaaS is very important to generate CSS with variables

You can install it on your MAC by typing the below command:

brew install sass/sass/sass

if you are not using MAC, click the URL https://sass-lang.com/install for details to install it for other OS

sudo gem install sass

Now, suppose I am working on my WordPress Theme to generate CSS, I will have to use mac console to switch to theme folder which is located at /Applications/MAMP/htdocs/bdproject/blog/wp-content/themes/taskgum/assets

Now in console type:

cd /Applications/MAMP/htdocs/bdproject/blog/wp-content/themes/taskgum/assets

saas –watch saas:css

You ca learn SaaS freely from this youtube channel:
https://www.youtube.com/watch?v=ok3y4E5NEmw&list=PLriKzYyLb28nvORWgaD0hAbBcJUcsxy16