❔ CSProj DefineConstants

  <PropertyGroup>
        ...
    <Configurations>Debug;Release;WIN-STEAM;MAC-STEAM;LIN-STEAM;WIN-GOG;MAC-GOG;LIN-GOG</Configurations>
  </PropertyGroup>
  <PropertyGroup>
      <DefineConstants Condition="'$(Configuration)' == 'WIN-STEAM'">$(DefineConstants);WINDOWS;STEAM</DefineConstants>
      <DefineConstants Condition="'$(Configuration)' == 'MAC-STEAM'">$(DefineConstants);MACOS;STEAM</DefineConstants>
      <DefineConstants Condition="'$(Configuration)' == 'LIN-STEAM'">$(DefineConstants);LINUX;STEAM</DefineConstants>
      <DefineConstants Condition="'$(Configuration)' == 'WIN-GOG'">$(DefineConstants);WINDOWS;GOG</DefineConstants>
      <DefineConstants Condition="'$(Configuration)' == 'MAC-GOG'">$(DefineConstants);MACOS;GOG</DefineConstants>
      <DefineConstants Condition="'$(Configuration)' == 'LIN-GOG'">$(DefineConstants);LINUX;GOG</DefineConstants>
      <DefineConstants Condition="'$(Configuration)' == 'Debug'">$(DefineConstants);WINDOWS;STEAM</DefineConstants>
  </PropertyGroup>

#if MACOS && STEAM
            Console.WriteLine("Mac");
#endif