<section>
  <div class="center">
    <h4>Normal State</h4>
    <a class="button" href="#0">
      <span>
        <em>Download</em>
        <i class="fa fa-download"></i>
      </span>
    </a>
    <br>
    <br>
    <h4>Hover state</h4>
    <br>
    <br>
    <br>
    <a class="button hover" href="#0">
      <span>
        <em>Download</em>
        <i class="fa fa-download"></i>
      </span>
    </a>
  </div>
</section>

@import  url(https://fonts.googleapis.com/css?family=Montserrat);

*,
*::after,
*::before {
  box-sizing: border-box;
}

body {
  background: #39393A;
  font-size: 1.2rem;
  font-family: Montserrat;
  letter-spacing: 1px;
  color: white;
}

a {
  text-decoration: none;
  color: white;
}

em {
  font-style: normal;
}

section {
  width: 100%;
  height: 100vh;
  display: table;
}

section .center {
  display: table-cell;
  text-align: center;
  vertical-align: middle;
}

.button {
  position: relative;
  background: #E75A7C;
  display: inline-block;
  height: 60px;
  width: 200px;
  border-radius: 50em;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.7), inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

span,
em,
i {
  position: absolute;
  width: 100%;
  height: 100%;
  left: 0;
}

span {
  overflow: hidden;
}

.button em {
  top: 0;
  line-height: 60px;
}

.button i {
  top: 100%;
  line-height: 60px;
}

.button:hover em,
.button.hover em{
  top: -100%;
}

.button:hover i,
.button.hover i{
  top: 0%;
}

em,
i {
  transition: top 0.3s;
}

.button::before,
.button::after {
  position: absolute;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s;
}

.button::before {
  content: 'File Size: 5mb';
  width: 160px;
  height: 60px;
  background: #0E84A1;
  border-radius: 0.25em;
  bottom: 90px;
  line-height: 60px;
  left: calc(50% - 80px);
  font-size: 15px;
}

.button::after {
  content: '';
  width: 0px;
  height: 0px;
  border: 10px solid transparent;
  border-top-color: #0E84A1;
  bottom: 70px;
  left: calc(50% - 10px);
}

.button:hover::before,
.button:hover::after,
.button.hover::before,
.button.hover::after{
  opacity: 1;
  visibility: visible;
}

.button:hover::before,
.button.hover::before{
  bottom: 80px;
}

.button:hover::after,
.button.hover::after{
  bottom: 60px;
}