title: Change color of contents in Mat Expansion on hover and focus
body: <p>I am writing css to change the color of the text and arrow indicator on focus and hover. However the indicator arrow acts separately. I want it to change when you hover over the whole panel. Currently the arrow indicator only changes when you hover directly over it Basically when the whole panel has the focus or hover change the title and indicator to my css: <a href="https://stackblitz.com/edit/angular-imycgv?file=styles.css" rel="nofollow noreferrer">https://stackblitz.com/edit/angular-imycgv?file=styles.css</a></p>
  
  <pre><code>.mat-expansion-indicator:hover::after,
  .mat-expansion-indicator:focus::after{
    color: yellow;
  }
  
  .mat-expansion-panel:hover,
  .mat-expansion-panel:focus{
    background-color: red;
  }
  .mat-expansion-panel-header-description:hover, .mat-expansion-panel-header-title:hover,
  .mat-expansion-panel-header-description:focus, .mat-expansion-panel-header-title:focus{
    color: orange;
  }
      }
  </code></pre>