@media only screen and ( max-width: 640px ) {
    .navbar-header{ display: flex; align-items: center; justify-content: space-between;padding: 0 10px;flex-direction:row-reverse;}
    .navbar-default .navbar-brand{width: 80%;}
    .navbar-default .navbar-toggle{margin-right: 0;}
    .navbar-header:after,.navbar-header:before{content: normal;}
    .navbar-brand>img{width:100%;display: inline-block;}
}