nix-config/home/system/dunst.nix

{ pkgs, ... }:
{
  home.packages = with pkgs; [ libnotify ];

  services.dunst = {
    enable = true;
    package = pkgs.dunst;

    settings = {
      global = {
        follow = "mouse";

        width = "0 , 600";
        height = "400";

        origin = "top-center";
        offset = "0x10";
      };

      fullscreen_delay_everything = {
        fullscreen = "delay";
      };
    };
  };
}