How to customise style Blockquote - whistyun/Markdown.Avalonia GitHub Wiki
Blockquote are created as Border which has 'Blockquote' class.
<!--
xmlns:ctxt="clr-namespace:ColorTextBlock.Avalonia;assembly=ColorTextBlock.Avalonia"
-->
<Style Selector="Border.Blockquote">
<Setter Property="BorderBrush" Value="Red" />
<Setter Property="Background" Value="Pink" />
<Setter Property="BorderThickness" Value="4,12,8,16"/>
<Setter Property="CornerRadius" Value="20"/>
</Style>
> ## heading in blockquote
> some tex in blockquote
> * listitem1
> * listitem2