OK, try replacing your rule with something like this:
.mi_navbar-fixed-top {
z-index: 1030;
}
@media screen and (max-width: 772px) {
.mi_navbar-fixed-top {
top: 0px;
border-width: 0px 0px 1px;
position: fixed;
right: 0px;
left: 0px;
z-index: 1030;
}
.mi_navbar-fixed-top .navbar-collapse {
max-height: 340px;
}
}
It should, hopefully, fix both issues. If you still have any troubles, please post a link to some kind of live demo that I could test.
Cheers!
