.post-body iframe{width:100%!important;} @media screen and (max-width:960px){ .post-body iframe{max-height:90%}} @media screen and (max-width:768px){ .post-body iframe{max-height:75%}} @media screen and (max-width:600px){ .post-body iframe{max-height:60%}} @media screen and (max-width:480px){ .post-body iframe{height:auto!important;max-height:auto!important}}