.btn {
  --color1: #1a8516;
  --color2: #236b19;
  perspective: 1000px;
  padding: 1em 1em;
  background: linear-gradient(var(--color1), var(--color2));
  border: none;
  outline: none;
  font-size: 20px;
  text-transform: uppercase;
  letter-spacing: 4px;
  color: #fff;
  text-shadow: 0 10px 10px #000;
  cursor: pointer;
  transform: rotateX(70deg) rotateZ(30deg);
  transform-style: preserve-3d;
  transition: transform 0.5s;
}

.btn::before {
  content: "";
  width: 100%;
  height: 15px;
  background-color: var(--color2);
  position: absolute;
  bottom: 0;
  right: 0;
  transform: rotateX(90deg);
  transform-origin: bottom;
}

.btn::after {
  content: "";
  width: 15px;
  height: 100%;
  background-color: var(--color1);
  position: absolute;
  top: 0;
  right: 0;
  transform: rotateY(-90deg);
  transform-origin: right;
}

.btn:hover {
  transform: rotateX(30deg) rotateZ(0);
}