.pa-underline-fade nav ul li a{position:relative}.pa-underline-fade nav ul li a::before{content:"";position:absolute;left:0;bottom:0;height:2px;width:100%;background-color:#4db6e6;z-index:2;opacity:0;display:block;-webkit-transition:.3s;-o-transition:.3s;transition:.3s;-webkit-transition-timing-function:cubic-bezier(.58,.3,.005,1);-o-transition-timing-function:cubic-bezier(.58,.3,.005,1);transition-timing-function:cubic-bezier(.58,.3,.005,1)}.pa-underline-fade nav ul li a:hover::before{opacity:1}