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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #0A3C2F;
}

.container {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 30px;
    background: #0D614B;
    padding: 40px 60px;
}

h2 {
    font-size: 3em;
    color: #FFF;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.reset {
    padding: 15px 20px;
    color: #267C65;
    background: #FFF;
    border: none;
    font-size: 1.5em;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    cursor: pointer;
    font-weight: 600;
}

.reset:focus {
    color: #FFF;
    background: #267C65;
}

.game {
    width: 430px;
    height: 430px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    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: #FFF;
    transform: rotateY(180deg);
    transition: 0.5s;
    cursor: pointer;
}

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

.item::after {
    content: "";
    position: absolute;
    inset: 0;
    background: #209D7B;
    transition: 0.5s;
    transform: rotateY(0deg);
    backface-visibility: hidden;
    -moz-backface-visibility: hidden;
}

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

.game.nonCliquable {
    pointer-events: none;
}

@media screen and (max-width: 595px) {
    h2 {
        text-align: center;
    }

    .game {
        width: 370px;
        height: 370px;
        justify-content: center;
    }

    .item {
        width: 75px;
        height: 75px;
    }
}