{ config, pkgs, ... }: {
  environment.systemPackages = with pkgs; [
    # gtk
    gnome3.adwaita-icon-theme
    arc-theme arc-icon-theme
    unstable.solarc

    # qt
    libsForQt5.qtstyleplugins
  ];

  environment.extraInit = ''
    # SVG loader for pixbuf (needed for GTK svg icon themes)
    export GDK_PIXBUF_MODULE_FILE=$(echo ${pkgs.librsvg.out}/lib/gdk-pixbuf-2.0/*/loaders.cache)

    # Set GTK_DATA_PREFIX so that GTK+ can find the themes
    export GTK_DATA_PREFIX=${config.system.path}
      
    # find theme engines
    export GTK_PATH=${config.system.path}/lib/gtk-3.0:${config.system.path}/lib/gtk-2.0
  '';

  users.primary.files = {
    ".gtkrc-2.0" = {
      mode = "444";
      text = ''
        gtk-icon-theme-name="solarc-dark"
        gtk-theme-name="SolArc-Dark"
      '';
    };

    ".config/gtk-3.0/settings.ini" = {
      mode = "444";
      text = ''
        [Settings]
        gtk-icon-theme-name=solarc-dark
        gtk-theme-name=SolArc-Dark
      '';
    };

    ".config/Trolltech.conf" = {
      mode = "444";
      text = ''
        [Qt]
        style=gtk
      '';
    };
  };
}