:host {
  display: block;
}

nav {
  height: 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-color: #d8d8d8;
}

ul li {
  list-style: none;
  display: inline;
}

a {
  margin: 0 15px;
  color: inherit;
  text-decoration: none;
}

a:hover {
  padding-bottom: 5px;
  box-shadow: inset 0 -2px 0 0 #333;
}