<Window.Resources>
<Style TargetType="Button">
<Style.Setters>
<Setter Property="Height" Value="30" />
<Setter Property="Width" Value="50" />
<Setter Property="Content" Value="Button" />
<Setter Property="Foreground" Value="Red" />
</Style.Setters>
<Style.Triggers>
<!--<Trigger Property="IsMouseOver" Value="True">
<Trigger.Setters>
<Setter Property="FontSize" Value="30" />
<Setter Property="Width" Value="100" />
<Setter Property="Height" Value="80" />
</Trigger.Setters>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsFocused" Value="True" />
<Condition Property="IsMouseOver" Value="True" />
</MultiTrigger.Conditions>
<MultiTrigger.Setters>
<Setter Property="Foreground" Value="Aquamarine" />
</MultiTrigger.Setters>
</MultiTrigger>-->
<EventTrigger RoutedEvent="Mouse.MouseEnter">
<EventTrigger.Actions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation
Storyboard.TargetProperty="FontSize"
To="30"
Duration="0:0:0.2" />
</Storyboard>
</BeginStoryboard>
</EventTrigger.Actions>
</EventTrigger>
</Style.Triggers>
</Style>
</Window.Resources>
<Grid>
<StackPanel>
<Button />
<Button />
<Button />
<Button />
</StackPanel>
</Grid>
