_frontend_code/theme/src/tokens.css

@custom-media --screen-sm (min-width: 640px);
@custom-media --screen-md (min-width: 768px);
@custom-media --screen-lg (min-width: 1024px);
@custom-media --screen-xl (min-width: 1280px);
@custom-media --screen-xxl (min-width: 1536px);