span.nav-unerline{border-bottom:2px solid transparent;transition:border-bottom .3s ease}.header .nav li .router-link-active span.nav-underline,.header .nav li .router-link-active-parent span.nav-underline,.header .nav li .router-link-exact-active span.nav-underline,.router-link-active span.nav-unerline,.router-link-active-parent span.nav-unerline,.router-link-exact-active span.nav-unerline{border-bottom:2px solid #07f3b7}