如何为JavaFX项目使用CSS

I am quite new to JavaFX and was wondering if there is a way to assign a css file to the entire JavaFX project/scene. Currently, I have to apply the stylesheet to every element I want to be styled with css. I am working with IntelliJ and Scene Builder 2.0. I have tried adding the stylesheets in my Main class, start method as shown below but it did not seem to have the desired effect.I am quite new to JavaFX and was wondering if t