.sp-megamenu-parent>li:after {
    line-height: 80px;
    content: '';
    width: 0;
    height: 3px;
    background: #000;
    display: block;
    margin: -20px auto 20px auto;
	transition: ease all 0.3s;
}

.sp-megamenu-parent>li:hover:after {
    width: 100%;
}