Admin style bootstrap nav-stacked improvements, has css3 white box arrow with black theme

bootstrap-nav-stacked-admin.css

.nav.nav-stacked .nav-item {
    border-bottom: 1px solid #666;
}

.nav.nav-stacked .nav-item a {
    color: #fff;
    border-radius: 0;
    position: relative;
}

.nav.nav-stacked .nav-item.active a:after {
    left: 100%;
    top: 50%;
    content: " ";
    height: 0;
    width: 0;
    position: absolute;
    pointer-events: none;
    border: 10px solid rgba(255, 255, 255, 0);
    border-right-color: #ffffff;
    margin-top: -10px;
    margin-left: -20px;
}

.nav.nav-stacked .nav-item a:hover {
    color: #ddd;
    background: rgba(255, 255, 255, .2);
}

.nav.nav-stacked .active {
    border-left: 4px solid rgb(25, 170, 141);
}

.nav.nav-stacked .nav-item.active a {
    color: #333;
    background: rgba(255, 255, 255, .8);
}

.nav.nav-stacked .nav-label .toggle-icon {
    float: right;
}

.nav.nav-stacked .nav-second-level .nav-item {
    background: rgba(255, 255, 255, .1);
}