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

h1{
    color: white;
    font-family: Arial, Helvetica, sans-serif;
    margin-top: 10px;
    margin-bottom: 10px;
    font-size: 35px;
}
body{
    height: 100vh;
    background: rgb(5, 30, 171);
    display: grid;
    place-items: center;
    margin: 0;      
    padding: 0;
}

.memory-game{
    width: 500px;
    height: 490px;
    margin: auto;
    display: flex;
    flex-wrap: wrap;
    perspective: 1000px;

}
.memory-card{
    margin-top: 5px;
    width: calc(25% - 10px);
    height: calc(33.333% - 10px);
    margin: 5px;
    position: relative;
    transform: scale(1);
    transform-style: preserve-3d;
    transition: transform .5s;
    box-shadow: 1px 1px 1px rgba(69, 155, 225, 0.3);
}

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

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


.front-face, 
.back-face{
    width: 100%;
    height: 100%;
    padding: 20px;
    position: absolute;
    border-radius: 5px;
    background:  rgb(136, 150, 231);
    backface-visibility: hidden;
}

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