@media only screen and (max-width: 600px) {

    .btn-one { 
    font-size: 14px;
    }

    .box {
        display: block;
        text-align: center;
    }
    
    .social-link span { 
        margin: auto !important;
    }
    
    .navbar-brand {
        margin: auto;
    }
    
    button.navbar-toggler {
        display: none;
    }
}