{ pkgs, lib, ... }:
let commaSep = builtins.concatStringsSep ",";
in {
  services.xserver = {
    layout = commaSep [ "de" "gr" "ru" ];
    xkbVariant = commaSep [ "T3" "polytonic" "phonetic" ];
    xkbOptions =
      commaSep [ "compose:caps" "terminate:ctrl_alt_bksp" "grp:ctrls_toggle" ];
    libinput.enable = true;
  };

  console.keyMap = "de";

  # improve held key rate
  services.xserver.displayManager.sessionCommands =
    "${pkgs.xorg.xset}/bin/xset r rate 300 50";
}