Animations faded on NG-IF

CSS

<style>
.animate-if {
  background:white;
  border:1px solid black;
  padding:10px;
}

.animate-if.ng-enter, .animate-if.ng-leave {
  transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 0.5s;
}

.animate-if.ng-enter,
.animate-if.ng-leave.ng-leave-active {
  opacity:0;
}

.animate-if.ng-leave,
.animate-if.ng-enter.ng-enter-active {
  opacity:1;
}
</style>

HTML

<label>Click me: <input type="checkbox" ng-model="checked" ng-init="checked=true" /></label><br/>
Show when checked:
<span ng-if="checked" class="animate-if">
  This is removed when the checkbox is unchecked.
</span>