Add arrow to MatTooltip

I would like to add an arrow below with MatTooltip on Angular 16.But for some reason overriding the Material with a pseudo element for an arrow doesnt work as suggested in many posts. Here is my code :

<th class="value-style" matTooltip={{tile.tooltip}} [matTooltipPosition]='tooltipPosition' matTooltipClass="TooltipClass">{{tile.count}}</th>

In Scss

.homeTooltipClass {
  .mdc-tooltip__surface {
    background: rgba($color:black, $alpha: 1) !important;
    background-color: black;
    color: white !important;
    font-size: 14px !important;
    max-width: 200px !important;
    border: 1px solid black;
    padding: 5px;
    box-shadow: 1px 1px black;    
  }
}

 public tooltipPosition: TooltipPosition = "above";

Solution

Really I can not imagine how you draw the "arrow", but you need take account three things

The .css should be in a "global" style (e.g. in the styles.css of your application. Material angular create the tooltip in a cdk-panel "outside" the application.
You should indicate overflow:visible to your tooltip
```
.mat-tooltip.TooltipClass{
  overflow: visible;
}
```

An example of draw a bottom arrow

.mat-tooltip.TooltipClass::after {
  content: " ";
  position: absolute;
  top: 100%; /* At the bottom of the tooltip */
  left: 50%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: rgba(97, 97, 97, .9) transparent transparent transparent;
}

A stackblitz

NOTE: in material v16, the class should be mat-mdc-tooltip