*,
*::before,
*::after {
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  background-color: #ccc;
  perspective: 800px;
}

.btn {
  width: 300px;
  height: 100px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.3s ease-in-out;
  transform: translateZ(-50px);
}

.btn:hover {
  transform: rotateX(-90deg) translateY(50px);
}

.side {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  position: absolute;
  font-size: 3rem;
  font-weight: bold;
  backface-visibility: hidden;
}

.default-side {
  background-color: white;
  border: 10px solid #069;
  color: #069;
  transform: translateZ(50px);
}

.hover-side {
  background-color: #069;
  color: white;
  transform: rotateX(90deg) translateZ(50px);
}