Ttrouble Making My Responsive Theme Mobile Friendly

I have Theme Twenty Eleven, version 1.2 . The Theme is supposed to be responsive, but doen’t render well in mobile devices. Google made several suggestions including changing absolute widths to percentage widths. I have so many elements with widths such as lines, photos, videos, etc. I don’t know how to make their widths responsive without ruinging the site’s appearance. My site is http://www.1stchoiceplumbinginc.com