I'm having issues getting the :active pseudo element to work in Internet Explorer. Have a look at the link below in a very narrowed Internet Explorer web browser. You will notice that when you click and hold on the hamburger button, logo, Twitter icon or nav menu buttons, you will notice nothing happens except the hamburger will display it's pushing in effect because it's a button.

Have a look at it on Chrome and you will see that the colour changes when you click and hold on one of the above elements. This is what should be happening in every browser.

What do I need to change in my code to get this working in Internet Explorer?

http://bit.ly/1U08lza

The menu button works for me in IE. The only thing I see different is that the ACM grid dots goes behind the menu button in IE and stays in front on FX.

That's interesting. Are you specifically talking about the :active state? If you hold down ANY of the buttons you should see the :active state kick in - the opacity of that button changes to 0.4. What IE version are you using?