What's the best way to style the responsive menu? I'm just

Hi,

What's the best way to style the responsive menu? I'm just trying to make it look like the WPMU responsive menu (all the way to the left) with 3 lines. I'd like it almost identical to that simple one on your site. I have tried to edit the css but am a bit lost.

If possible, can I put a small icon there? like from font awesome?

Any help would be much appreciated. Here is an attached menu of what I'd like.

Thank you