Cant set the theme

[tolgayilmaz86]

I was trying to make Dark mode by default (no switch enabled, only one theme)
but

set this in App.axaml

...RequestedThemeVariant="Dark">

  <Application.Styles>
    <themes:NeumorphismTheme BaseTheme="Dark" PrimaryColor="Purple" SecondaryColor="Lime" />
  </Application.Styles>

also tried different thigs like setting

Application.Current.SetValue(ThemeVariantScope.ActualThemeVariantProperty, ThemeVariant.Dark);

in different places.
None worked out.
In the design view I can see dark theme for my top menu bar for example but not for my mainwindow in any way.