.buttonCenter{
    margin-left: auto;
    display: block;
    width: 200px;
    margin-right: auto;
}

@media (max-width: 991px) and (min-width: 768px) {
header .col-md-3 {
    float: left;
    width: 40% !important;
    margin-right: 40% !important;
}

section#footer-credits {
    display: none;
}
}

@media (max-width: 767px) and (min-width: 481px){
header .col-md-3 {
    float: left;
    width: 40% !important;
    margin-right: 40% !important;
}
}