@media only screen and (min-width: 480px), only screen and (min-device-width: 480px) {
    .login-box
    {
        width:500px !important;
    }
    
    .form-control,.btn
    {
        font-size: 25px !important;
        line-height: 25px !important;
        height: 45px !important;
    }
}