<nav>
      <ul class="menu">
        <li><a href="">Home</a></li>
        <li><a href="">Order Status</a></li>
        <li><a href="">Tweets</a></li>
        <li><a href="">Read Our History</a></li>
        <li><a href="">Contact Us</a></li>
      </ul>
    </nav>

    <div class="wrapper">
      <p>Lorem ipsum dolor sit amet, <a href="">consectetur</a> adipisicing elit. Est <a href="">explicabo</a> unde natus necessitatibus esse obcaecati distinctio, aut itaque, qui vitae!</p>
      <p>Aspernatur sapiente quae sint <a href="">soluta</a> modi, atque praesentium laborum pariatur earum <a href="">quaerat</a> cupiditate consequuntur facilis ullam dignissimos, aperiam quam veniam.</p>
      <p>Cum ipsam quod, incidunt sit ex <a href="">tempore</a> placeat maxime <a href="">corrupti</a> possimus <a href="">veritatis</a> ipsum fugit recusandae est doloremque? Hic, <a href="">quibusdam</a>, nulla.</p>
      <p>Esse quibusdam, ad, ducimus cupiditate <a href="">nulla</a>, quae magni odit <a href="">totam</a> ut consequatur eveniet sunt quam provident sapiente dicta neque quod.</p>
      <p>Aliquam <a href="">dicta</a> sequi culpa fugiat <a href="">consequuntur</a> pariatur optio ad minima, maxime <a href="">odio</a>, distinctio magni impedit tempore enim repellendus <a href="">repudiandae</a> quas!</p>
    </div>
html {
  box-sizing: border-box;
}
*, *:before, *:after {
  box-sizing: inherit;
}
body {
  min-height: 100vh;
  margin: 0; /* Important! */
  font-family: sans-serif;
  background:
    linear-gradient(45deg, hsla(340, 100%, 55%, 1) 0%, hsla(340, 100%, 55%, 0) 70%),
    linear-gradient(135deg, hsla(225, 95%, 50%, 1) 10%, hsla(225, 95%, 50%, 0) 80%),
    linear-gradient(225deg, hsla(140, 90%, 50%, 1) 10%, hsla(140, 90%, 50%, 0) 80%),
    linear-gradient(315deg, hsla(35, 95%, 55%, 1) 100%, hsla(35, 95%, 55%, 0) 70%);
}

.wrapper {
  margin:0 auto;
  max-width:500px;
  font-size: 20px;
  line-height: 2;
  position: relative;
}

a {
  text-decoration: none;
  color:darkblue;
  padding: 2px;
  background:rgba(0,0,0,0.05);
  border-radius: 20px;
}

.highlight {
  transition: all 0.4s;
  border-bottom:2px solid white;
  position: absolute;
  top:0;
  background:white;
  left:0;
  z-index: -1;
  border-radius:20px;
  display: block;
  box-shadow: 0 0 10px rgba(0,0,0,0.2);
}

.menu {
  padding: 0;
  display: flex;
  list-style: none;
  justify-content: center;
  margin:100px 0;
}

.menu a {
  display: inline-block;
  padding:5px;
  margin:0 20px;
  color:black;
}
const highlight = document.createElement('span')
highlight.classList.add('highlight')
document.body.appendChild(highlight)

const triggers = document.querySelectorAll('a');
triggers.forEach(a => a.addEventListener('mouseenter', highlightLink))

function highlightLink() {
  const linkCoords = this.getBoundingClientRect();
  console.log(linkCoords);
  const coords = {
    //width and height are absolute
    width: linkCoords.width,
    height: linkCoords.height,
    
    // we need to add scroll since 
    //top,left are relative to the viewport
    top: linkCoords.top + window.scrollY,
    left: linkCoords.left + window.scrollX
  };

  highlight.style.width = `${coords.width}px`;
  highlight.style.height = `${coords.height}px`;
  highlight.style.transform = `translate(${coords.left}px, ${coords.top}px)`;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.