@import url(https://fonts.googleapis.com/css?family=Open+Sans:600);
.frame {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 400px;
  height: 400px;
  margin-top: -200px;
  margin-left: -200px;
  border-radius: 2px;
  box-shadow: 1px 2px 10px 0px rgba(0, 0, 0, 0.12);
  overflow: hidden;
  background: #BDCEDB;
  color: #fff;
  font-family: 'Open Sans', Helvetica, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-perspective: 150px;
          perspective: 150px;
}

.cb {
  display: none;
}

.button {
  position: absolute;
  display: block;
  width: 100px;
  height: 50px;
  top: 175px;
  left: 150px;
  border-radius: 25px;
  text-align: center;
  line-height: 46px;
  text-transform: uppercase;
  font-weight: 600;
  -webkit-transform-style: preserve-3d;
          transform-style: preserve-3d;
  -webkit-transition: all .5s ease-in-out;
  transition: all .5s ease-in-out;
  cursor: pointer;
  box-shadow: 4px 8px 12px 0 rgba(0, 0, 0, 0.1);
}
.button .front, .button .back {
  box-sizing: border-box;
  position: absolute;
  display: block;
  z-index: 2;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  color: #34495E;
  background: #fff;
  border: 2px solid #fff;
  border-radius: 25px;
  -webkit-backface-visibility: hidden;
          backface-visibility: hidden;
  -webkit-transform: rotateX(0);
          transform: rotateX(0);
}
.button .back {
  z-index: 1;
  color: #fff;
  background: #64C760;
  border: 2px solid #fff;
  -webkit-transform: rotateX(180deg);
          transform: rotateX(180deg);
}

.cb:checked ~ .button {
  -webkit-transform: rotateX(180deg);
          transform: rotateX(180deg);
  box-shadow: 4px -8px 12px 0 rgba(0, 0, 0, 0.1);
}