Hieu ung line chay khi hover chuot qua menu

Tạo hiệu ứng line đẹp mắt khi di chuột qua menu

//html

<div class="footerStuff">   
   <a href="#">Twitter</a>
</div>

//css


.footerStuff a {
    position: relative;
  text-decoration:none;
}
.footerStuff a:hover::after {
    width: calc(100% + 1px);
}
.footerStuff a::after {
    background-color: #333;
    bottom: 0;
    content: "";
    display: inline-block;
    height: 2px;
    left: 0;
    position: absolute;
    transition: width 0.3s cubic-bezier(0.15, 0.56, 0.17, 0.94) 0s;
    width: 0;
}