.btn {
  display: inline-block;
  background: #e2e2e2;
  border: 0;
  line-height: 2.5em;
  padding: 0 0 0 1em;
  margin-bottom: 1em;
  outline: none;
  text-decoration: none;
  color: #666;
}
.btn .arrow {
  display: inline-block;
  line-height: 2.5em;
  text-align: center;
  background: #333;
  color: white;
  font-size: 1em;
  width: 2.5em;
  -webkit-transition: margin 200ms;
  transition: margin 200ms;
  margin-left: .75em;
}
.btn:hover {
  background: white;
}
.btn:hover .arrow {
  margin-left: 1.25em;
  background-color: #262626;
}
.btn:active {
  background: #ccc;
}
.btn:active .arrow {
  margin-left: 1.5em;
}

.btn .arrow {
  background-color: indianred;
}
.btn:hover .arrow {
  background-color: #c14e4e;
}

.center {
  text-align: center;
}