I have an issue about jqueryUI tooltip..

In fact, impossible to change the css style of the class .ul-tooltip. .
specially on firefox. 

In more, even on the offical website.. On the demo : <https://jqueryui.com/tooltip/#custom-style>

When I look the style on firefox and on chrome, the style are different. 

I try to override the css 

```
.ui-tooltip {
  background: #fcfcfa !important;
  color: #86c724 !important;
  border: 1px solid #86c724 !important;
  border-radius: 5px !important;
  -moz-border-radius: 5px !important;
  padding: 10px !important;
  -webkit-box-shadow: 0 0 5px  rgba(0,0,0,0.25);
          box-shadow: 0 0 5px  rgba(0,0,0,0.25);
}

```

but no result. 

I try to add a new class and manage style by it.. no result

```
  <script>
  $(function() {
    $( ".infoboxcontainer" ).tooltip({
      tooltipClass: "myNewClass"
    });

  });
  </script>

```

No idea what happen.. it's like if firefox add is own css for tooltip.