Answers for "import scss files"

import mixin from another file

@import "../../../theme/main.scss"

sass import

@import 'path/to/file', 'other/file';

sass @use not working

As of 8/2020 @use is only compatible with Dart Sass. 
Check compatibility with documentation.
https://sass-lang.com/documentation/at-rules/use

Sass @import example

@import "reset";

body {

   
  font-family: Helvetica, sans-serif;
 
  font-size: 18px;
  color: red;
}