I'm currently working on a fixed navigation menu for a client on mobile. I have noticed that in Firefox when you set overflow-y: auto and a max height on a div that it will show the entire div in Chrome and Safari but in Firefox the bottom content is never revealed. I have created a code pen to show what I mean. Try and scroll to the Last item (Literally called "last") in Chrome and you can reach it but try and do the same in Firefox and you can't!
http://codepen.io/acha5066/pen/oXyXZz
max-height: 400px;
overflow-y: auto;
Anyone know what causes this or how to fix it?