.single_post_box
{
    text-align: right;
    direction: rtl;
    border: 1px solid grey;
    margin-right: auto;
    margin-left: auto;
    width: 70%;
    padding: 25px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

@media all and (max-width: 698px) 
{
    .single_post_box
    {
        width: 85%;
    }
}