트리거에서 WPF 설정 테두리 배경

MouseEnter가 발생할 때 경계 배경 속성을 변경하는 트리거를 만들어야합니다. 다음을 수행했습니다.

<Border Width="20" Height="30" Focusable="True">
        <Border.Background>
            <LinearGradientBrush>
                <LinearGradientBrush.GradientStops>
                    <GradientStop Color="Aquamarine" Offset="0"/>
                </LinearGradientBrush.GradientStops>
            </LinearGradientBrush>
        </Border.Background>
        <Border.Style>
            <Style TargetType="{x:Type Border}">
                <Style.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter Property="Background">
                            <Setter.Value>
                                <LinearGradientBrush>
                                    <LinearGradientBrush.GradientStops>
                                        <GradientStop Color="Aquamarine" Offset="0"/>
                                        <GradientStop Color="Beige" Offset="0.2"/>
                                        <GradientStop Color="Firebrick" Offset="0.5"/>
                                        <GradientStop Color="DarkMagenta" Offset="0.9"/>
                                    </LinearGradientBrush.GradientStops>
                                </LinearGradientBrush>
                            </Setter.Value>
                        </Setter>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </Border.Style>
    </Border>

하지만 작동하지 않습니다. 감사합니다.