@import url("https://fonts.googleapis.com/css?family=K2D:600");

.donate-button {
  position: relative;
  display: inline-block;
  z-index: 1;
  width: 150px;
  line-height: 50px;
  border-radius: 5px;
  border: 3px solid #000;
  color: #000;
  font-family: "K2D", sans-serif;
  font-size: 20px;
  text-decoration: none;
  text-align: center;
  background-image: linear-gradient(45deg, #f00, #ff0);
}

.donate-button:before {
  position: absolute;
  display: block;
  width: 100%;
  height: 100%;
  z-index: -1;
  content: "";
  opacity: 0;
  background-image: linear-gradient(45deg, #f0f, #f00);
  transition: opacity 400ms ease-out;
}

.donate-button:hover:before {
  opacity: 1;
}

.donate-button > span {
  display: inline-block;
}

.donate-button > span:nth-child(2) {
  width: 0;
  font-family: "Segoe UI", sans-serif;
  text-align: right;
  opacity: 0;
  transition: width 200ms ease-out, opacity 200ms ease-out 200ms;
}

.donate-button:hover > span:nth-child(2) {
  width: 2ch;
  opacity: 1;
}

.donate-button:not(:hover) > span:nth-child(2) {
  opacity: 0;
  transition: width 200ms ease-out 200ms, opacity 200ms ease-out;
}