小编ckl*_*n23的帖子

.orange-link {
  color: orange;
  position: relative;
  text-decoration: none;
}

.orange-link:before {
  content: "";
  position: absolute;
  width: 100%;
  height: 3px;
  background: orange;
  bottom: 0;
  border-radius: 5px;
  transform: scaleX(0);
  transition: .25s linear;
}

.orange-link:hover:before,
.orange-link:focus:before {
  transform: scaleX(1);
}

<p>Visit the official rules <a class="orange-link" href="#">here</a> on how to send in a write-in entry.</p>