{
  services.keyd = {
    enable = true;
    keyboards.default = {
      "main" = {
        rightbtn = "rightbtn";  # Keep normal RMB function
        "shift+rightbtn" = "layer(rmb1, 250)";  # Start sequence only if Shift is held
      };

      "rmb1" = {
        "shift+rightbtn" = "toggle(rightbtn)";  # Second press (Shift still held) toggles RMB
      };
    };
  };
}