.vertikal-zentrieren{display:flex;flex-direction:column;justify-content:center}#heading .nav li a::after{content:"";position:absolute;left:10%;bottom:-6px;width:80%;height:2px;background-color:#ffffff;transform:scaleX(0);transition:transform 0.3s ease-in-out}#heading .nav li a:hover::after{transform:scaleX(1)}