.menubutton {
    width: 46px;
    height: 40px;
    position: fixed;
    right: 6px;
    top: 6px;
    cursor: pointer;
    z-index: 12399994;
    display: none;
    background: #333;
}
@media (max-width: 900px) {
    .menu { display: none; }
    .menubutton { display: block; }
}

.menubutton:after {
    position: absolute;
    top: 18px;
    right: 6px;
    display: block;
    height: 4px;
    width: 30px;
    border-top: 3px solid #fff;
    border-bottom: 3px solid #fff;
    content: '';
    padding: 2px;
}
.menubutton:before {
    -webkit-transition: all .3s ease;
    -o-transition: all .3s esase;
    transition: all .3s ease;
    position: absolute;
    top: 7px;
    right: 6px;
    display: block;
    height: 3px;
    width: 34px;
    background: #fff;
    content: ''
}
.menubutton.menu-opened:after {
    -webkit-transition: all .3s ease;
    -o-transition: all .3s ease;
    transition: all .3s ease;
    top: 19px;
    border: 0;
    height: 3px;
    width: 30px;
    background: #fff;
    -webkit-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    transform: rotate(45deg);
    padding: 0px;
}
.menubutton.menu-opened:before {
    top: 19px;
    background: #fff;
    width: 30px;
    -webkit-transform: rotate(-45deg);
    -ms-transform: rotate(-45deg);
    transform: rotate(-45deg)
}