The portal is your first impression when the customers come in for support. We believe in paving the way to let your creative side take over and transform the way it looks! On the Garden plan, you would be able to perform only CSS customizations, which would be a common customization change for the entire portal. 

From the Estate plan onwards, you would have the ability to have page-level customizations which would allow you to modify almost all pages on your portal, individually. This is an article that would help you with an elaboration.