title: How to highlight a window in JavaFX?
body: <p>I'm working with JavaFX drag-n-drop file imports and I want the entire window (client area) to highlight blue whenever the user drags files over it. I know how to use the JavaFX input API and CSS just fine but don't know an easy way to do this. Is it possible to put a mask over the window, or will I just have to go through changing the background color of the root and every node? I want something like this (Mac window screenshot highlighting):</p>
  
  <p><a href="https://i.stack.imgur.com/KzNUJ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KzNUJ.jpg" alt="enter image description here"></a></p>