Thank you!

[netleader]

Truely I was looking for this since weeks and you made it! Thank you 1000 times!

Just in case here is my project config I have all NPM shit in a folder NpmJS, and I differ between publish and build. Maybe this helps someone else who has the same problem

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <IsWebConfigTransformDisabled>true</IsWebConfigTransformDisabled>
    <StaticWebAssetBasePath>_content</StaticWebAssetBasePath>
    <NodeFiles>NpmJS\</NodeFiles>
  </PropertyGroup

  <ItemGroup>
    <Content Remove="$(NodeFiles)**" />
    <None Remove="$(NodeFiles)**" />
    <None Include="$(NodeFiles)**" Exclude="$(NodeFiles)node_modules\**" />
  </ItemGroup>

  <ItemGroup>
    <styles Include="$(NodeFiles)src\app.css" />
    <Watch Include="@(styles)" />
  </ItemGroup>

  <Target Name="DeleteExistingBuild" BeforeTargets="ComputeFilesToPublish">
    <RemoveDir Directories="$(PublishDir)" />
    <Message Importance="high" Text="Cleared publish folder" />
  </Target>

  <Target Name="NpmInstall" Inputs="$(MSBuildProjectDirectory)\NpmJS\package-lock.json" Outputs="$(BaseIntermediateOutputPath)\NpmJS\package-lock.json">
    <Message Importance="high" Text="Restoring dependencies using 'npm'. This may take several minutes..." />
    <Exec Command="npm install" WorkingDirectory="$(MSBuildProjectDirectory)\NpmJS" />
    <Copy SourceFiles="$(MSBuildProjectDirectory)\NpmJS\package-lock.json" DestinationFolder="$(BaseIntermediateOutputPath)\NpmJS" SkipUnchangedFiles="true" />
  </Target>

  <Target Name="PostScopedCssCompile" AfterTargets="_GenerateScopedCssFiles" DependsOnTargets="NpmInstall">
    <Message Importance="high" Text="Building scoped css..." />
    <Exec Command="npx postcss @(_ScopedCssOutputs, ' ') --replace --config $(MSBuildProjectDirectory)\NpmJS" WorkingDirectory="$(MSBuildProjectDirectory)\NpmJS" EnvironmentVariables="TAILWIND_MODE=build" />
  </Target>

  <Target Name="PostStylesCssCompile" Inputs="@(styles)" Outputs="@(styles->'$(MSBuildProjectDirectory)\wwwroot\css\%(FileName)%(Extension)')" BeforeTargets="CoreBuild">
    <Message Importance="high" Text="(CoreBuild) Building styles css" />
    <Exec Command="npx postcss @(styles->'src\%(FileName)%(Extension)', ' ') --dir $(MSBuildProjectDirectory)\wwwroot\css --config $(MSBuildProjectDirectory)\NpmJS" WorkingDirectory="$(MSBuildProjectDirectory)\NpmJS" EnvironmentVariables="TAILWIND_MODE=build" />
  </Target>

  <Target Name="PostStylesCssPublish" Inputs="@(styles)" Outputs="@(styles->'$(PublishDir)\wwwroot\css\%(FileName)%(Extension)')" AfterTargets="ComputeFilesToPublish">
    <Message Importance="high" Text="(ComputeFilesToPublish) Building styles css" />
    <Exec Command="npx postcss @(styles->'src\%(FileName)%(Extension)', ' ') --dir $(PublishDir)\wwwroot\css --config $(MSBuildProjectDirectory)\NpmJS" WorkingDirectory="$(MSBuildProjectDirectory)\NpmJS" EnvironmentVariables="TAILWIND_MODE=build" />
  </Target>
</Project>

[uabarahona]

Thank you!, that is definitely going to help some of us, will keep the issue open for now, to see if I can add this somewhere in future templates.