Common field properties documents the styleName property as follows:

styleName. Optional. Adds one or more style names to this component. Multiple styles can be specified as a space-separated list of style names such as checkbox disabled. The style name will be rendered as an HTML class name, which can be used in a CSS definition. The class name is added to the field by calling the Vaadin method addStyleName.

This explanation is correct but incomplete. Please guide the user about where they should put the style rule. Should they add the CSS rule in the AdminCentral theme style sheet? If so, where is the AdminCentral CSS stored and how to edit it? Or should they create a completely new theme for their app in order to style the field?

Please provide another paragraph that guides the user about putting CSS rules in the right place.