Styling the Telerik RadTextBox can feel a little opaque, especially when you’re trying to override theme defaults that Telerik applies deep inside its CSS. Whether you’re adjusting colors, weights, or the way NullText behaves, the key is understanding which internal classes Telerik uses and how to override them safely. In this article, we’ll walk through the essential selectors you need, show what Telerik applies behind the scenes, and demonstrate how to take full control of the RadTextBox’s appearance with simple, targeted CSS. If you’ve ever fought with disabled or empty-state styling, this guide will save you time.