p5.js-web-editor/client/styles/abstracts/_mixins.scss

@mixin themify ($themes: $themes) {
  @each $theme, $map in $themes {
    .#{$theme} & {
      // Define theme color
      $theme-map : (
      ) !global;
      
      @each $key, $submap in $map {
        $value: map-fetch($themes, $theme '#{$key}');
        $theme-map: map-merge($theme-map, ($key: $value)) !global;
      } 
      
      @content;
      
      // reset theme color to null
      $theme-map: null !global;
    }
  }
}