<div class="outer">
  <div class="inner">
    <label>Back</label>
  </div>
</div>

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

body {
  background: #141926;
  font-family: Helvetica, Arial, sans-serif; 
}

.outer {
  position: relative;
  margin: auto;
  width: 70px;
  margin-top: 200px;
  cursor: pointer;
}

.inner {
  width: inherit;
  text-align: center;
}

label { 
  font-size: .8em; 
  line-height: 4em;
  text-transform: uppercase;
  color: #fff;
  transition: all .3s ease-in;
  opacity: 0;
  cursor: pointer;
}

.inner:before, .inner:after {
  position: absolute;
  content: '';
  height: 1px;
  width: inherit;
  background: #FFC107;
  left: 0;
  transition: all .3s ease-in;
}

.inner:before {
  top: 50%; 
  transform: rotate(45deg);  
}

.inner:after {  
  bottom: 50%;
  transform: rotate(-45deg);  
}

.outer:hover label {
  opacity: 1;
}

.outer:hover .inner:before,
.outer:hover .inner:after {
  transform: rotate(0);
}

.outer:hover .inner:before {
  top: 0;
}

.outer:hover .inner:after {
  bottom: 0;
}