{
  lib,
  config,
  pkgs,
  ...
}: let
  cfg = config.cherrykitten.common;
in {
  imports = [
    ../users
    ./security.nix
    ./yubikey.nix
    ../graphical
  ];

  options.cherrykitten.common = {
    test = lib.mkOption {
      type = lib.types.str;
      default = "nya";
      example = "nyanya";
    };
  };

  config = {
    nix.settings.experimental-features = ["nix-command" "flakes"];

    time.timeZone = "Europe/Berlin";

    i18n.defaultLocale = "en_US.UTF-8";
    console = {
      font = "Lat2-Terminus16";
      keyMap = lib.mkForce "de";
      useXkbConfig = true; # use xkb.options in tty.
    };

    fonts = {
      enableDefaultPackages = true;
      packages = with pkgs; [
        noto-fonts
        noto-fonts-cjk
        noto-fonts-emoji
        monaspace
        nerdfonts
      ];
      fontconfig = {
        defaultFonts.emoji = ["Noto Emoji"];
        defaultFonts.serif = ["Monaspace Xenon" "FiraCode Nerd Font" "Hack Nerd Font" "NotoSans Nerd Font"];
        defaultFonts.sansSerif = ["Monaspace Xenon" "FiraCode Nerd Font" "Hack Nerd Font" "NotoSerif Nerd Font"];
        defaultFonts.monospace = ["Monaspace Xenon" "FiraCode Nerd Font" "Hack Nerd Font"];
      };
    };

    # Packages used on all systems
    environment.systemPackages = with pkgs; [
      git
      openssl
      rsync
      pinentry
      wget
    ];
  };
}