I have now adjusted to:
@media only screen and (max-width: 767px) {
.modal-body,
.modal.in .modal-content {
width: 100%;
max-width: 380px;
}
.modal-dialog {
min-width: 100%;
}
.modal-dialog, .modal.fade .modal-dialog {
-webkit-transform: translate(-53%,-65.4%)!important;
-moz-transform: translate(-53%,-65.4%)!important;
-ms-transform: translate(-53%,-65.4%)!important;
transform: translate(-53%,-65.4%)!important;
}
.spb_tabs .nav-tabs li a {
padding: 10px 0px;
text-align: left;
}
}
End result: