weseek__growi/resource/styles/scss/_vendor.scss

// import bootstrap
$bootstrap-sass-asset-helper: true;
@import "~bootstrap-sass/assets/stylesheets/bootstrap";

// import bootstrap4 utility classes
@import "../bootstrap4/utilities";

// import toastr styles
@import '~toastr/build/toastr';

// import metismenu styles
@import '~metismenu/dist/metisMenu';