The width for mobile (Catch Evolution)

Dear sir, Hello. We would like to change the width of content for mobile. Default width is narrow and not good for Japanese words. Could you kindly tell us the CSS code we should insert? The following code is one we have tried but it does not work... @media screen and (max-width: 479px) .wrapper, .one-column.no-sidebar .site, .one-column.no-sidebar #fixed-header-top { max-width: 340px; } The URL of the site is as follows. http://cpa-exporter.com/blog/ Sincerely, Pitaro