* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

.container {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: sans-serif;
  background: #000;
}

ul {
  display: flex;
}

li {
  list-style: none;
}

ul li a {
  color: #fff;
  font-size: 2rem;
  text-decoration: none;
  padding: 0.4rem 1rem;
  margin: 0 10px;
  position: relative;
  transition: all 0.5s;
  text-transform: uppercase;
}

.list-items:before {
  content: "";
  position: absolute;
  bottom: 12px;
  left: 12px;
  width: 12px;
  height: 12px;
  border: 3px solid white;
  border-width: 0 0 3px 3px;
  opacity: 0;
  transition: all 0.6s;
}

.list-items:hover:before {
  opacity: 1;
  bottom: -8px;
  left: -8px;
}

.list-items:after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 12px;
  height: 12px;
  border: 3px solid white;
  border-width: 3px 3px 0 0;
  opacity: 0;
  transition: all 0.6s;
}

.list-items:hover:after {
  opacity: 1;
  top: -8px;
  right: -8px;
}