#post-171{ width:50%; margin:0 auto;}

.txt{border:1px solid #C2C8CD !important; padding:15px 20px !important; background:#e9f99f;}
.login label{color:#192474; font-weight:bold;}

@media screen and (max-width:720px) {
    
   #post-171{ width:100%;    box-sizing: border-box; }
    
}