@media (max-width: 980px) {
  /* Скрыть стрелки у подменю */
  .t-menusub__arrow,
  .t-menu-base__list .t-menusub__arrow,
  .t-menu__link-wrapper .t-menusub__arrow {
    display: none !important;
    width: 0 !important;
    height: 0 !important;
    overflow: hidden !important;
  }
}