Mobile site too narrow

My site is thestylistquo.com and I’m using a child theme of Twenty Twelve.

I’ve found that my mobile site is <i>incredibly</i> narrow and hard-to-read! I’ve read a few of the threads on the forum and think that might be because I have fixed widths in my stylesheet. I’m unsure how to style my blog using only percentages! I had trouble with making my sidebar wide enough, my margins small enough, etc. Can someone help me with this? I’ve tried to find some resources online, but not much so far.

Thanks