Daca sidebar si sidebar right sunt acelasi lucru, ceva de genul:

Cod:
@media only screen and (min-width:768px) and (max-width:987px){
    #content{
        min-width:466px;
        width:61%;
    }
    #sidebar{
        min-width:237px;
        width:31%;
    }
}
@media only screen and (max-width:767px){
    #content, #sidebar{
        min-width: 0;
        width: auto;
    }
    #sidebar{
        display:block;
        float:none;
    }
}