title: How to customize javafx scrollbar thumb thickness by css?
body: <p>I tried to set thickness by <code>-fx-pref-height: 10px;</code> when orientation is horizontal, and by <code>-fx-pref-width: 10px;</code> when scrollbar orientation is vertical. But is doesn't work.</p>
  
  <pre><code>.scroll-bar:horizontal .thumb {
      -fx-background-color: derive(black, 90%);
      -fx-background-insets: 2, 0, 0;
      -fx-background-radius: 0em;
      -fx-pref-height: 10px;
  }
  
  .scroll-bar:vertical .thumb {
      -fx-background-color: derive(black, 90%);
      -fx-background-insets: 2, 0, 0;
      -fx-background-radius: 0em;
      -fx-pref-width: 10px;
  }
  </code></pre>
  
  <p>How to achieve this by customizing css?</p>