I would like to change the orientation of a `StackPanel` depending on the screen size.

I've been following [this answer](https://stackoverflow.com/a/33087428/1438809) but haven't got things working yet.

Here's what I've got so far:

```
<VisualStateManager.VisualStateGroups>
    <VisualStateGroup x:Name="SharedVisualStates">
        <VisualState x:Name="DefaultLayout">
            <VisualState.StateTriggers>
                <AdaptiveTrigger MinWindowWidth="720" />
            </VisualState.StateTriggers>
            <VisualState.Setters>
                <Setter Target="GuidesList.Style" Value="{StaticResource DefaultGuidesList}" />
            </VisualState.Setters>
        </VisualState>
        <VisualState x:Name="NarrowLayout">
            <VisualState.StateTriggers>
                <AdaptiveTrigger MinWindowWidth="0" />
            </VisualState.StateTriggers>
            <VisualState.Setters>
                <Setter Target="GuidesList.Style" Value="{StaticResource NarrowGuidesList}" />
            </VisualState.Setters>
        </VisualState>
    </VisualStateGroup>
</VisualStateManager.VisualStateGroups>

<Page.Resources>
    <Style x:Key="DefaultGuidesList" TargetType="StackPanel" >
        <Setter Property="Orientation" Value="Horizontal"/>
    </Style>

    <Style x:Key="NarrowGuidesList" TargetType="StackPanel" >
        <Setter Property="Orientation" Value="Vertical"/>
    </Style>
</Page.Resources>

<StackPanel
    x:Name="GuidesList">
    <StackPanel ... />
    <StackPanel ... />
</StackPanel>

```

Any ideas?