django-import-export

1. Add unfold.contrib.import_export to INSTALLED_APPS at the beginning of the file. This action will override all templates coming from the application.
2. Change import_form_class and export_form_class in ModelAdmin which is inheriting from ImportExportModelAdmin. This chunk of code is responsible for adding proper styling to form elements.

# admin.py

from unfold.admin import ModelAdmin
from import_export.admin import ImportExportModelAdmin
from unfold.contrib.import_export.forms import ExportForm, ImportForm, SelectableFieldsExportForm

class ExampleAdmin(ModelAdmin, ImportExportModelAdmin):
    import_form_class = ImportForm
    export_form_class = ExportForm
    # export_form_class = SelectableFieldsExportForm

When implementing import_export.admin.ExportActionModelAdmin class in admin panel, import_export plugin adds its own implementation of action form which is not incorporating Unfold CSS classes. For this reason, unfold.contrib.import_export.admin contains class with the same name ExportActionModelAdmin which inherits behavior of parent form and adds appropriate CSS classes.

Note: This class has been removed and in new version (4.x) of django-import-export it is not needed.

admin.py

from unfold.admin import ModelAdmin
from unfold.contrib.import_export.admin import ExportActionModelAdmin

class ExampleAdmin(ModelAdmin, ExportActionModelAdmin):
    pass