Semi.Avalonia/src/Semi.Avalonia/Themes/Shared/ComboBox.axaml

<ResourceDictionary xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <StaticResource x:Key="ComboBoxSelectorCornerRadius" ResourceKey="SemiBorderRadiusSmall" />
    <StaticResource x:Key="ComboBoxSelectorThickness" ResourceKey="SemiBorderThicknessControl" />
    <Thickness x:Key="ComboBoxItemDefaultPadding">12 8</Thickness>
    <Thickness x:Key="ComboBoxSelectorDefaultPadding">12 0 0 0</Thickness>
    <x:Double x:Key="ComboBoxPopupMaxDropDownHeight">504</x:Double>
    <StaticResource x:Key="ComboBoxPopupBorderThickness" ResourceKey="SemiBorderThicknessControl" />
    <StaticResource x:Key="ComboBoxPopupBoxCornerRadius" ResourceKey="SemiBorderRadiusMedium" />
    <x:Double x:Key="ComboBoxIconWidth">32</x:Double>
    <StaticResource x:Key="ComboBoxIcon" ResourceKey="SemiIconChevronDown" />
    <StaticResource x:Key="ComboBoxPopupBorderMargin" ResourceKey="SemiThicknessExtraTight" />
    <Thickness x:Key="ComboBoxPopupBorderPadding">0 4</Thickness>
    <StaticResource x:Key="ComboBoxDefaultHeight" ResourceKey="SemiHeightControlDefault" />
    <StaticResource x:Key="ComboBoxSmallHeight" ResourceKey="SemiHeightControlSmall" />
    <StaticResource x:Key="ComboBoxLargeHeight" ResourceKey="SemiHeightControlLarge" />
</ResourceDictionary>