Sass error compiling Pro Stepper steppers.scss:

I assumed that if I want to use Steppers in compile via sass I need to import steppers.scss. But doing so gives the error below

Expected behavior Stepper Pro css would be included by default. Or at least importing steppers.scss should compile without error

Actual behavior

ERROR in ./resources/assets/sass/vendor.scss
Module build failed (from ./node_modules/css-loader/index.js):
ModuleBuildError: Module build failed (from ./node_modules/sass-loader/lib/loader.js):

  & ul.stepper.horizontal .step-new-content,
 ^
      Top-level selectors may not contain the parent selector "&".
    ╷
332 │ ┌   & ul.stepper.horizontal .step-new-content,
333 │ │   & ul.stepper.horizontal .step-actions {
    │ └────────────────────────────────────────^
    ╵
  node_modules/mdbvue/build/scss/addons-pro/_steppers.scss 332:3  @import

Resources (screenshots, code snippets etc.)

This is in a laravel based project using webmix. There are no other compile errors (MDBVue is latest 5.4)

Please advise how to proceed