compile scss to css by npm

The most direct way to make this happen is in your terminal. Once Sass is installed, you can compile your Sass to CSS using the sass command.  Once Sass is installed, you can compile your Sass to CSS using the sass command. You’ll need to tell Sass which file to build from, and where to output CSS to. For example, running

style.scss from sass folder and  compile that file to style.css from css folder.

sass --watch assets/scss/style.scss:assets/css/style.css