update to v1.4.0

HandyControlDemo/UserControl/Controls/CirclePanelDemoCtl.xaml

@@ -2,7 +2,7 @@
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:controls="clr-namespace:HandyControl.Controls;assembly=HandyControl"
-             Background="White">
+             Background="{DynamicResource RegionBrush}">
     <controls:TransitioningContentControl>
         <controls:CirclePanel Margin="64" Diameter="170">
             <Button Style="{StaticResource CirclePanelButton}"/>