Rewrite my ./generated/traveldroid/todo/desktop/gtk.nix  to integrate nicely with my existing flake.nix en host.nix


------------------------------------------------------------------------
{ pkgs, user, ... }:
{
  environment.systemPackages = with pkgs; [
      gtk3     # GTK target
      gtk4     # GTK target
    ];
  # Stylix GTK target
  stylix.targets.gtk.enable = true;

  home-manager.users.${user.username} = {
    gtk = {
      enable = true;
      theme = {
        name = "Catppuccin-Mocha-Standard-Blue-Dark";
        package = pkgs.magnetic-catppuccin-gtk;
      };
      iconTheme = {
        name = "Papirus-Dark";
        package = pkgs.papirus-icon-theme;
      };
      gtk3.extraConfig = {
        gtk-application-prefer-dark-theme = 1;
      };
      gtk4.extraConfig = {
        gtk-application-prefer-dark-theme = 1;
      };
    };

  };
}

------------------------------------------------------------------------

flake.nix

{
  description = "Droidnix: A dendritic NixOS + Home Manager configuration";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

    home-manager = {
      url = "github:nix-community/home-manager";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    import-tree.url = "github:vic/import-tree";

    stylix = {
      url = "github:nix-community/stylix";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    zen-browser = {
      url = "github:youwen5/zen-browser-flake";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    hyprland.url = "github:hyprwm/Hyprland";
  };

  outputs = { self, nixpkgs, home-manager, import-tree, stylix, hyprland, zen-browser, ... }:
    let
      system = "x86_64-linux";
      flakeRoot = self;
    in {
      nixosConfigurations = {
        traveldroid = nixpkgs.lib.nixosSystem {
          inherit system;

          modules = [
            ./generated/hosts/traveldroid/host.nix
          ];

          specialArgs = {
            inherit flakeRoot;
            inherit home-manager import-tree stylix hyprland zen-browser;
          };
        };
      };
    };
}

------------------------------------------------------------------------

host.nix

{ lib, config, pkgs, flakeRoot, import-tree, home-manager, ... }:

let
  hostname = "traveldroid";

  modulesPath = "${flakeRoot}/generated/modules/${hostname}";
  usersPath   = "${flakeRoot}/generated/users";

  hostModules = import-tree modulesPath;
  globalUsers = import-tree usersPath;

  allModules = hostModules.imports ++ globalUsers.imports;

in
{
  #################################
  # Core system config
  #################################

  networking.hostName = hostname;
  system.stateVersion = "26.05";

  #################################
  # Imports
  #################################

  imports =
    [
      ./boot.nix
      ./hardware-configuration.nix

      # REQUIRED for Home Manager
      home-manager.nixosModules.home-manager
    ]
    ++ allModules;

  #################################
  # Home Manager integration
  #################################

  home-manager.useGlobalPkgs = true;
  home-manager.useUserPackages = true;
}