.nav-underline {
    padding-left: 0;
    margin-bottom: 0;
    list-style: none;
}
.nav-underline::before,
.nav-underline::after {
    display: table;
    content: " ";
}
.nav-underline > li {
    position: relative;
    display: block;
	float: left;
}
.nav-underline > li > a {
    position: relative;
    display: block;
    padding: 10px 15px;
}
.nav-underline > li > a:hover,
.nav-underline > li > a:focus {
	text-decoration: none;
}
.nav-underline > li > a::before {
	content: '';
	position: absolute;
	bottom: 0;
	left: 100%;
	width: 0;
	height: 3px;
	background: lightsteelblue;
	transition: all .3s;
}
.nav-underline > li.active > a::before {
	background: steelblue;
}
.nav-underline > li.active > a::before,
.nav-underline > li:hover > a::before {
	left: 0;
	width: 100%;
}
.nav-underline > li:hover ~ li > a::before {
	left: 0;
}