That site appears to be using a modified twentytwelve? That theme IS responsive already. What changes have you made?
Generally better to use a Child Theme - easier to find changes you've made - http://codex.wordpress.org/Child_Themes
That site appears to be using a modified twentytwelve? That theme IS responsive already. What changes have you made?
Generally better to use a Child Theme - easier to find changes you've made - http://codex.wordpress.org/Child_Themes