[class^="list-number"] {
  padding-left: 2.5em;
  counter-reset: li;
}
[class^="list-number"] * {
  padding: 0;
}
[class^="list-number"] li {
  padding: 0.2em 0;
}
[class^="list-number"] a {
  position: relative;
  display: block;
  padding: 0.3em 1em;
  text-decoration: none;
  color: #333;
  font-weight: 500;
  background-color: #fff;
  box-shadow: 0.5rem 0.5rem 2rem rgba(0,0,0,0.1);
  transition: all 1s ease-in-out;
}
[class^="list-number"] a:focus,
[class^="list-number"] a:hover,
[class^="list-number"] a:active {
  color: #5f5f5f;
  background-color: #e4e4e4;
}

.list-number a::after {
  content: '';
  position: absolute;
  left: -1rem;
  top: 50%;
  margin-top: -0.5rem;
  border: 0.5rem solid transparent;
  transition: all 0.1s ease-out;
}
.list-number a:focus::after,
.list-number a:hover::after,
.list-number a:active::after {
  left: -0.5rem;
  border-left-color: #777;
}
.list-number-rounded a {
  border-radius: 1em;
}
.list-number-rounded a::before,
.list-number-rounded a::after {
  top: 50%;
  height: 2.1em;
  width: 2.1em;
  border-radius: 50%;
  transition: all 0.3s ease-out;
}
.list-number-rounded a::after {
  content: '';
  display: block;
  position: absolute;
  height: 2.1em;
  width: 2.1em;
  left: -2.5em;
  top: calc(50% - 1em);
  z-index: -1;
}
.list-number-rounded a:focus::before,
.list-number-rounded a:hover::before,
.list-number-rounded a:active::before {
  transform: rotate(360deg);
}