ngx-admin/src/app/@theme/styles/styles.scss

// themes - our custom or/and out of the box themes
@import 'variables';

// framework component themes (styles tied to theme variables)
@import '~@nebular/theme/styles/globals';
@import '~@nebular/auth/styles/all';

// custom global styles
@import 'global';

// install the framework and custom global styles
@include nb-install() {
  @include nb-theme-global();
  @include nb-auth-global();
  @include ngx-global-theme();
};