WPF求助：自定义按钮的鼠标悬停样式不生效

刚刚开始学习WPF，遇到了这个问题
希望实现鼠标悬停在关闭按钮和最小化按钮时按钮背景变色为浅灰和红色（就像很多应用那样），但其变为默认的颜色，一直没有找到为什么。
新手菜菜，希望大佬们指点捏！
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<Window x:Class="WpfApp1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp1"
mc:Ignorable="d"
Title="MainWindow"
WindowState="Maximized" WindowStyle="None"
ResizeMode="NoResize" Topmost="True">
<Window.Resources>
<!-- 最小化按钮样式 -->
<Style x:Key="MinimizeButtonStyle" TargetType="Button">
<Setter Property="Background" Value="Transparent" />
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Yellow" />
</Trigger>
</Style.Triggers>
</Style>
<!-- 关闭按钮样式 -->
<Style x:Key="CloseButtonStyle" TargetType="Button">
<Setter Property="Background" Value="Transparent"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Red"/>
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="32" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Image Source="Images/background.png" Stretch="UniformToFill"
HorizontalAlignment="Center" VerticalAlignment="Top"
Grid.ColumnSpan="2" Grid.RowSpan="2"/>
<Border Background="#000000" MouseDown="DragWindow" Margin="0,0,0,0"
Opacity="0.5" Grid.Row="0" Grid.ColumnSpan="2"/>
<TextBlock Text="我的自定义标题栏" VerticalAlignment="Center"
Foreground="#ffffff" FontSize="14" Margin="9,0,0,0" Opacity="0.6"
Grid.Row="0" HorizontalAlignment="Left" />
<!-- 最小化按钮 -->
<Button x:Name="MinimizeButton" Style="{StaticResource MinimizeButtonStyle}"
Width="64" Height="32"
VerticalAlignment="Center" HorizontalAlignment="Right"
Margin="0,0,63,0" Grid.Row="0" Grid.ColumnSpan="2"
Click="MinimizeButton_Click" BorderBrush="#000000">
<Path Data="M0,6 L14,6" Stroke="#ffffff" StrokeThickness="2" Opacity="0.6"/>
</Button>
<!-- 关闭按钮 -->
<Button x:Name="CloseButton" Style="{StaticResource CloseButtonStyle}"
Width="64" Height="32"
VerticalAlignment="Center" HorizontalAlignment="Right"
Margin="0,0,0,0" Grid.Row="0" Grid.ColumnSpan="2"
Click="CloseButton_Click" BorderBrush="#000000">
<Path Data="M0,0 L10,10 M10,0 L0,10" Stroke="#ffffff" StrokeThickness="2" Opacity="0.6"/>
</Button>
</Grid>
</Window>
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