.navbar-toggle {
  z-index:3;
}

.navbar-default {
  background-color:#ffffff;
  background-image:none;
}

@media screen and (min-width:768px) {
  .navbar-brand-centered {
    position:absolute;
    left:50%;
    display:block;
    width:160px;
    text-align:center;
  }
}

@media screen and (min-width:768px) {
  .navbar > .container .navbar-brand-centered, .navbar > .container-fluid .navbar-brand-centered {
    margin-left:-80px;
  }
}