.-center li {
  margin: 15px;
  position: relative;
  width: 230px;
  height: 376px;
  display: inline-block;
  vertical-align: top;
  -webkit-perspective: 300px;
          perspective: 300px;
  -webkit-transform-origin: 50% 50% 90px;
          transform-origin: 50% 50% 90px;
}
li:nth-child(1) .w { top: 50px;

}
li:nth-child(2) .w { bottom: 50px;

}
li:nth-child(3) .w { top: 50px;

}
li:nth-child(4) .w { bottom: 50px;

}
.-center li span{ font-size:24px; color:#262626;}

.-center li:nth-child(4) span{ font-size:24px; color:#262626; bottom:0; left:70px; position:absolute;}
.-center li:nth-child(2) span{ font-size:24px; color:#262626; bottom:0; left:70px; position:absolute;}

.w {
  font-size: medium;
  font-size: initial;
  position: absolute;
  top:0px;
  right: 0;
  bottom: 0;
  left: 0;
  pointer-events: none;
  -webkit-transform-style: preserve-3d;
          transform-style: preserve-3d;
  -webkit-transform-origin: 50% 50% -90px;
          transform-origin: 50% 50% -90px;
  will-change: transform;
  -webkit-animation: 200ms ease-out 0ms 1 normal forwards paused;
          animation: 200ms ease-out 0ms 1 normal forwards paused;
}

.f,
.b {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  color: white;
  -webkit-transition: none;
  transition: none;
}

.f {
  /*background-color: #00BCD4;
  background: -webkit-linear-gradient(#00BCD4, #673AB7);
  background: linear-gradient(#00BCD4, #673AB7);*/
  -webkit-transform: translate3d(0,0,0);
          transform: translate3d(0,0,0)
}

.f > svg{
  mix-blend-mode: luminosity;
}

.b {
  padding: 16px;
  padding: 1rem;
  background-image: -webkit-radial-gradient(circle, #ade707, #006837 100%);
  background-image: radial-gradient(circle, #ade707, #006837 100%);
  -webkit-transform: translate3d(0,0,-1px);
          transform: translate3d(0,0,-1px);

  display: -webkit-box;

  display: -ms-flexbox;

  display: flex;
  -webkit-box-align: center;
      -ms-flex-align: center;
          align-items: center;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
  text-shadow: 0 20px 20px black;
  text-align: center;
}

.in-top .b,
.out-top .b {
	margin-left:30px;
 -webkit-transform-origin: 0% 0%;
          transform-origin: 0% 0%;
  -webkit-transform: translate3d(100%, 0, 0) rotate3d(0,1,0,90deg);
          transform: translate3d(100%, 0, 0) rotate3d(0,1,0,90deg);
}

.in-right .b,
.out-right .b {
	margin-left:30px;
  -webkit-transform-origin: 0% 0%;
          transform-origin: 0% 0%;
  -webkit-transform: translate3d(100%, 0, 0) rotate3d(0,1,0,90deg);
          transform: translate3d(100%, 0, 0) rotate3d(0,1,0,90deg);
}

.in-bottom .b,
.out-bottom .b {
	margin-right:30px;
  -webkit-transform-origin: 100% 0;
          transform-origin: 100% 0;
  -webkit-transform: translate3d(-100%,0,0) rotate3d(0,-1,0,90deg);
          transform: translate3d(-100%,0,0) rotate3d(0,-1,0,90deg);
}

.in-left .b,
.out-left .b {
	margin-right:30px;
  -webkit-transform-origin: 100% 0;
          transform-origin: 100% 0;
  -webkit-transform: translate3d(-100%,0,0) rotate3d(0,-1,0,90deg);
          transform: translate3d(-100%,0,0) rotate3d(0,-1,0,90deg);
}

.in {
}

.in-top .w{
  -webkit-animation-name: in-right;
          animation-name: in-right;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

.in-right .w{
  -webkit-animation-name: in-right;
          animation-name: in-right;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

.in-bottom .w{
   -webkit-animation-name: in-left;
          animation-name: in-left;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

.in-left .w{
  -webkit-animation-name: in-left;
          animation-name: in-left;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

.out {
}

.out-top .w{
  -webkit-animation-name: out-right;
          animation-name: out-right;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

.out-right .w{
  -webkit-animation-name: out-right;
          animation-name: out-right;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

.out-bottom .w{
  -webkit-animation-name: out-left;
          animation-name: out-left;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

.out-left .w{
  -webkit-animation-name: out-left;
          animation-name: out-left;
  -webkit-animation-play-state: running;
          animation-play-state: running;
}

@-webkit-keyframes in-top {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(-1,0,0,90deg);transform: rotate3d(-1,0,0,90deg)}
}

@keyframes in-top {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(-1,0,0,90deg);transform: rotate3d(-1,0,0,90deg)}
}
@-webkit-keyframes out-top {
  from {-webkit-transform: rotate3d(-1,0,0,90deg);transform: rotate3d(-1,0,0,90deg)}
  to   {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}
@keyframes out-top {
  from {-webkit-transform: rotate3d(-1,0,0,90deg);transform: rotate3d(-1,0,0,90deg)}
  to   {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}

@-webkit-keyframes in-right {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(0,-1,0,90deg);transform: rotate3d(0,-1,0,90deg)}
}

@keyframes in-right {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(0,-1,0,90deg);transform: rotate3d(0,-1,0,90deg)}
}
@-webkit-keyframes out-right {
  from  {-webkit-transform: rotate3d(0,-1,0,90deg);transform: rotate3d(0,-1,0,90deg)}
  to    {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}
@keyframes out-right {
  from  {-webkit-transform: rotate3d(0,-1,0,90deg);transform: rotate3d(0,-1,0,90deg)}
  to    {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}

@-webkit-keyframes in-bottom {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(1,0,0,90deg);transform: rotate3d(1,0,0,90deg)}
}

@keyframes in-bottom {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(1,0,0,90deg);transform: rotate3d(1,0,0,90deg)}
}
@-webkit-keyframes out-bottom {
  from  {-webkit-transform: rotate3d(1,0,0,90deg);transform: rotate3d(1,0,0,90deg)}
  to    {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}
@keyframes out-bottom {
  from  {-webkit-transform: rotate3d(1,0,0,90deg);transform: rotate3d(1,0,0,90deg)}
  to    {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}

@-webkit-keyframes in-left {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(0,1,0,90deg);transform: rotate3d(0,1,0,90deg)}
}

@keyframes in-left {
  from  {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
  to    {-webkit-transform: rotate3d(0,1,0,90deg);transform: rotate3d(0,1,0,90deg)}
}
@-webkit-keyframes out-left {
  from  {-webkit-transform: rotate3d(0,1,0,90deg);transform: rotate3d(0,1,0,90deg)}
  to    {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}
@keyframes out-left {
  from  {-webkit-transform: rotate3d(0,1,0,90deg);transform: rotate3d(0,1,0,90deg)}
  to    {-webkit-transform: rotate3d(0,0,0,0deg);transform: rotate3d(0,0,0,0deg)}
}

/* ======= aesthetics ======= */



header {
  padding-bottom: 48px;
  padding-bottom: 3rem;
}

h1 {
  font-size: 2em
}

h1 sup{
  font-size: .7em;
  color: #00BCD4;
}



ul::after{
  content: '';
  display: table;
  clear: both;
}

footer {
  font-size: 12px;
  font-size: .75rem;
  font-family: monospace;
  padding-top: 48px;
  padding-top: 3rem
}

footer a{
  display: inline-block;
  vertical-align: middle;
}

footer svg{
  fill: currentColor;
}


.-center {
  text-align: center;
  margin-bottom:100px;
}