Forms are a critical part of most of the business applications. As the web standards are getting evolved so is the expectation around user experience. Keeping up with the pace at which styling is evolving can be quite challenging for citizen developers who might not have the skill sets for creating custom CSS files.
Keeping this in mind, AgilePoint NX has taken up an initiative of providing OOTB theme templates in AgilePoint store, which can be just downloaded and applied on the form. The more technical users can even tweak those themes a bit instead of starting the styling effort from scratch.
There is now a category specially dedicated to eForms theme. You would see a lot more themes being added over next few months. Please refer to the below mentioned video on a quick overview of this feature.