body {
    padding-top: 50px;
}

.dropdown:hover {
    -moz-box-shadow: inset 0 0 5px #a9a9a9;
    -webkit-box-shadow: inset 0 0 5px #a9a9a9;
    box-shadow: inset 0 0 5px #a9a9a9;
}

.dropdown:hover .dropdown-menu {
    display: block;
}