@media all and (min-width:65em) {
    #left_column {
        display: inline
    }

    #middle_column {
        width: 50%;
        margin: auto;
    }
}

@media screen and (max-width: 700px)
{
    #middle_column {
        margin: 20% auto;
    }
    #game_content
    {
        margin-top: 20%;
    }
}