title: Adding shadow to angular material tooltip arrow
body: <p>I'm trying to add a shadow to angular material tooltip arrow but couldn't able to do it. If you can see in the <a href="https://stackblitz.com/edit/angular-tooltip-material-tdvx1i?file=src%2Fapp%2Ftooltip%2Fbasictooltip.css" rel="nofollow noreferrer">stackblitz</a> I have customized the tooltip with an arrow but not able to add a shadow to the arrow.</p>
  <p>My tooltip CSS:</p>
  <pre><code>::ng-deep .tooltip-class {
    background-color: #ffffff !important;
    opacity: 1;
    color: rgba(0, 0, 0, 0.87) !important;
    margin: 0 8px;
    padding: 8px 12px;
    font-size: 16px;
    font-style: normal;
    font-weight: 500;
    line-height: 24px;
    border-radius: 6px;
    overflow: visible !important;
    box-shadow: 0px 1px 2px #00000029, 0px 2px 4px #0000001f,
      0px 1px 8px #0000001a;
  }
  
  ::ng-deep .tooltip-class:before {
    border-right-color: white !important;
  }
  
  ::ng-deep .tooltip-class:after {
    content: '';
    position: absolute;
    top: 40%;
    right: 100%;
    margin-top: -5px;
    border-width: 10px;
    border-style: solid;
    border-color: transparent #fff transparent transparent;
  }
  </code></pre>