mobile-config-firefox/src/userChrome/appMenu.css

/* Copyright 2021 Oliver Smith
   SPDX-License-Identifier: GPL-3.0-or-later */

@media (max-width: 700px) {
	.subviewbutton,
	.toolbaritem-combined-buttons {
	  font-size: 8pt;
	}

	#appMenu-protection-report-button,
	#appMenuRestoreLastSession,
	#appMenu-customize-button,
	#appMenu-open-file-button,
	#appMenu-more-button,
	#appMenu-developer-button,
	#appMenu-whatsnew-button,
	#appMenu-help-button,
	#appMenu-quit-button {
	  display: none;
	}

	toolbarseparator {
	  display: none;
	}

	/* Zoom/edit: move controls to the left (so they are visible), hide
	 * label (it's obvious what they do) and spacer */
	#appMenu-zoom-controls spacer,
	#appMenu-zoom-controls label,
	#appMenu-edit-controls spacer,
	#appMenu-edit-controls label {
	  display: none;
	}

	/* Zoom/edit: center the controls somewhat */
	#appMenu-zoom-controls {
	  padding-left: 20px;
	}
	#appMenu-edit-controls {
	  padding-left: 15px;
	}

	/* Zoom: hide fullscreen button (not possible to exit fullscreen
	 * without keyboard) */
	#appMenu-fullscreen-button {
	  display: none;
	}
}