a.footer-btn {
  position: relative;
  display: inline-block;
  background: #ffffff;
  color: #333333;
  border: none;
  border-radius: 3px;
  width: 100%;
  font-size: 110%;
  line-height: 2;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  padding: 1em 2em;
  transition: all 0.4s;
}
a.footer-btn:visited {
  background: #ffffff;
  color: #333333;
  border: none;
  text-decoration: none;
}
a.footer-btn:active {
  background: #333333;
  color: #ffffff;
  border: none;
  text-decoration: none;
}
a.footer-btn:hover {
  background: #333333;
  color: #ffffff;
  border: none;
  text-decoration: none;
  opacity: 1;
}
a.footer-btn:before {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  right: 50%;
  display: block;
  height: 2px;
  background: #ffffff;
  transition: all 0.4s;
}
a.footer-btn:hover:before {
  left: 0;
  right: 0;
  background: #ffffff;
}