CSS

css dropdown menu with scrollbar

/*  Note that I added a screen width limit to 600px 
and fixed the menu height in 200px (with scrollbars), 
so you can adjust those numbers the way you want. */
@media (max-width: 600px) {
	#menu{
		max-height: 200px;
		overflow-x: hidden;
		overflow-y: auto;
	}
}