*{
    margin:0;
    padding: 0;
    box-sizing: border-box;
    font-family: monospace;
}
body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: rgb(240, 169, 15);
}
.container{
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 30px;
    background:rgb(230, 198, 129) ;
    padding: 40px 60px;
}

h2{
    font-size: 3.5rem;
    color: black;
    letter-spacing: 0.1rem;

}
.set{
    padding: 15px 20px;
    color:rgb(250, 171, 2) ;
    background: white;
    border: none;
    font-size: 1.5em;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    cursor: pointer;
    font-weight: 650;
}
.set:focus{
    color: white;
    background: rgb(240, 169, 15);
}
.game{
    width: 450px;
    height: 450px;
    display: flex;
    flex-wrap: wrap;
    gap: 11px;
    transform-style: preserve-3d;
    perspective: 500px;
}
.item{
    position: relative;
    width: 100px;
    height: 100px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 3em;
    background: white;
    transform: rotateY(180deg);
    transition: 0.25s; 
}

.item.boxOpen{
    transform: rotateY(0deg);
}

.item::after{
    content: '';
    position: absolute;
    inset: 0;
    background: rgb(211, 155, 36);
    transition: .25s;
    transform: rotateY(0deg);
    backface-visibility: hidden;
}

.boxOpen:after,
.boxMatch::after{
    transform: rotateY(180deg);
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    h2 {
        font-size: 2rem;
    }
    .set {
        padding: 8px;
        font-size: 1em;
    }
}