问悬停效果达不到网页末尾

EN

<div id="collapsable-nav" class="navbar-collapse collapse in" aria-expanded="true" style="">

    <ul id="nav-list" class="nav navbar-nav navbar-right">
    <li class="visible-xs text-center"></li>
    <li class="visible-xs text-center"><a href="#">Chicken</a></li>
    <li class="visible-xs text-center"><a href="#">Beef</a></li>
    <li class="visible-xs text-center"><a href="#">Sushi</a></li>
    </ul>

</div>

.navbar-default .navbar-collapse, .navbar-default .navbar-form {
    border-color: #e7e7e7;
}
.container-fluid>.navbar-collapse, .container-fluid>.navbar-header, .container>.navbar-collapse, .container>.navbar-header {
    margin-right: -15px;
    margin-left: -15px;
}

.navbar-collapse.in {
    overflow-y: auto;
}
.collapse.in {
    display: block;
}
.navbar-collapse {
    padding-right: 15px;
    padding-left: 15px;
    overflow-x: visible;
    -webkit-overflow-scrolling: touch;
    border-top: 1px solid transparent;
    -webkit-box-shadow: inset 0 1px 0 rgb(255 255 255 / 10%);
    box-shadow: inset 0 1px 0 rgb(255 255 255 / 10%);
}