style.css

*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
body{
    height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: rgb(54, 189, 189);
}
.memory-game{
    height: 640px;
    width: 640px;
    margin: auto;
    display: flex;
    flex-wrap: wrap;
    perspective: 1000px;
}
.card{
    height: calc(33.333% - 10px);
    width: calc(25% - 10px);
    margin: 5px;
    position: relative;
    box-shadow: 1px 1px 1px rgba(1, 1, 1, .3);
    cursor: pointer;
    transform: scale(1);
    transform-style: preserve-3d;
    transition: transform 0.9s;
}
.card:active{
    transform: scale(0.97);
    transition: transform .3s;
}
.card-front, 
.card-back{
    width: 100%;
    height: 100%;
    padding: 20px;
    position: absolute;
    border-radius: 5px;
    background-color: #fff;
    backface-visibility: hidden;
}
.card-front{
    transform: rotateY(180deg);
}
.card.flip{
    transform: rotateY(180deg); 
}

footer{
    display: flex;
    flex-direction: column;
    align-items: center;
}
footer .description{
    font-weight: 700;
    align-items: center;
}
footer .social-media{
    display: flex;
    justify-content: center;
    width: 100vw;
    align-items: center;
    font-size: small;
    margin-bottom: 10px;
    background-color: #fff;
    margin-top: 10px;

}
footer .img{
    margin-left: 15px;
}
footer img{
    width: 20px;
    height: 20px;
}
@media(max-width: 992px) {
    .memory-game{
        height: 500px;
        width: 500px;
    }
    .description, .social-media{
        width: 100vw;
        padding: 10px;
    }
}