* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

body {
  height: 100vh;
  display: flex;
}

.memory-game {
width: calc(100vh * 1.34);
height: 100vh;
  margin: auto;
  display: flex;
  flex-wrap: wrap;
  perspective: 1000px;
  padding: 20px;
}

.memory-card {
	width: calc((100vh * 1.34 - 6 * 15px) / 4);
	height: calc((100vh - 5 * 15px) / 3);
	margin: 5px;
	position: relative;
	transform: scale(1);
	transform-style: preserve-3d;
	transition: transform .5s;
	box-shadow: 1px 1px 1px rgba(0,0,0,.3);
	border-radius: 20px;
}

.memory-card:active {
  transform: scale(0.97);
  transition: transform .2s;
}

.memory-card.flip {
  transform: rotateY(180deg);
}

.front-face,
.back-face {
  width: 100%;
  height: 100%;
  position: absolute;
  border-radius: 5px;
  background: #1A5F48;
  backface-visibility: hidden;
}
.front-face{
background: #C5C7C7;
}


.front-face {
  transform: rotateY(180deg);
}