<Style TargetType="Button">
            <Setter Property="Template" Value="{StaticResource ButtonTemplate}" />
            <Setter Property="Template">
                <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <ControlTemplate.Triggers>
                        <EventTrigger RoutedEvent="Button.Click">
                            <BeginStoryboard>
                                <Storyboard AutoReverse="True">
                                    <DoubleAnimation To="0" Duration="0:0:0.1" Storyboard.TargetProperty="Width" />
                                    <DoubleAnimation To="0" Duration="0:0:0.1" Storyboard.TargetProperty="Height" />
                                </Storyboard>
                            </BeginStoryboard>
                        </EventTrigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
                </Setter.Value>
            </Setter>