Use your terminal and go to
/themes/themag_st/build to install the package. Run
npm install or
yarn install depending of what package manager you use.
gulp scss to compile the subtheme.scss or
gulp watch to watch for changes in subtheme.scss and automatically compile.
libraries-override: themag/global-styling: css: theme: assets/css/themag.css: false
To override TheMAG SCSS variables and components please see the instructions and examples written in the _variables.scss and subtheme.scss files.