<section>
  <a href="#" class="btn">
    <span class="btn-content">Call To Action</span>
    <span class="icon"><i class="fa fa-arrow-right" aria-hidden="true"></i></span>
  </a>
  <a href="#" class="btn btn-remove btn-alt-color">
    <span class="btn-content">Remove</span>
    <span class="icon"><i class="fa fa-times" aria-hidden="true"></i></span>
  </a>
  <hr />
  <a href="#" class="btn">
    <span class="btn-content">This is a Long Call to Action<br> with a Line Break</span>
    <span class="icon"><i class="fa fa-arrow-right" aria-hidden="true"></i></span>
  </a>
</section>
$btn-color: #009CD0;
$btn-alt-color: salmon;
.btn {
  border-radius: 4px;
  border: 2px solid $btn-color;
  color: $btn-color;
  display: inline-block;
  margin: 0 .25em;
  overflow: hidden;
  padding: 24px 60px 24px 16px;
  position: relative;
  text-decoration: none;
  line-height: 1;
  .btn-content {
    font-size: 1em;
    line-height: 1.2;
    padding: 0 26px;
    position: relative;
    right: 0;
    transition: right 300ms ease;
    display: block;
    text-align: left;
  }
  .icon {
    border-left: 1px solid $btn-color;
    position: absolute;
    right: 0;
    text-align: center;
    top: 50%;
    transition: all 300ms ease;
    transform: translateY(-50%);
    width: 58px;
    height: 70%;
    i {
      position: relative;
      top: 50%;
      transform: translateY(-50%);
    }
  }
  &:after {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    right: 0;
    left: 0;
    background-color: $btn-color;
    opacity: 0;
    transition: opacity 300ms ease;
  }
  &:hover {
    .btn-content {
      right: 100%;
    }
    .icon {
      border-left: 0;
      font-size: 1.8em;
      width: 100%;
    }
    &:after {
      opacity: .2;
    }
  }
  &.btn-alt-color {
    border-color: $btn-alt-color;
    color: $btn-alt-color;
    .icon {
      border-left-color: $btn-alt-color;
    }
    &:after {
      background-color: $btn-alt-color;
    }
  }
}
View Compiled
//included Font Awesome through JS
//Update: You can now have multiple line button without it looking wonky!

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://use.fontawesome.com/ff9a5d262d.js