My website navigation contains a dropdown. On mobile the collapsed dropdown is too long to be fully visible on a phone like iPhone 6, so it needs to scroll.
How can I make the dropdown scrollable, and prevent the rest of the website behind it from scrolling?
Making your users scroll your drop down menu is not recommended for best user experience.
Instead, make the menu open up as a fullscreen overlay on the page and reduce the font size or make it 2 columns, similar to http://hugeinc.com (view on mobile device).