* {
    box-sizing: border-box;
}

body {
    margin: 0;
    display: flex;
    height: 100vh;
    justify-content: center;
    align-items: center;
    background-color: #8cb9d5;
}

.game-panel {
    padding: 5px;
    display: flex;
    flex-direction: column;
    width: 400px;
    height: 400px;
    border-radius: 5px;
    background: white;
    box-shadow: 0 0 43px -14px rgba(66, 68, 90, 1);
}

.repeat {
    cursor: pointer;
    background-color: #008ada;
    border: solid transparent;
    border-radius: 10px;
    color: #ffffff;
    font-size: 15px;
    font-weight: bold;
    padding: 13px 16px;
    text-align: center;
    vertical-align: middle;
}

.repeat:hover {
    background: #7e7e7e;
}

.game-info {
    display: flex;
    justify-content: space-between;
    padding: 10px;
    font: bold 14px Verdana, Arial;
}

.deck {
    padding: 10px;
    display: grid;
    width: 100%;
    height: 100%;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    gap: 10px;
    perspective: 600px;
}

.card {
    position: relative; 
    width: 100%;
    height: 100%;
    transition: transform 1s;
    transform-style: preserve-3d;
    color: white;
    cursor: pointer;    
}

.card-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
}

.card-front {
    background: #7e7e7e;
}

.card-back {
    background: #008ada;
    transform: rotateY(180deg);
}

.card.is-flipped {
    transform: rotateY(180deg);
}

.deck i {
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 10px;
    font-size: 32px;
}

@media only screen and (max-width: 600px) {
    .game-panel {
        width: 100vw;
        height: 100vw;
        margin: 20px;
    }
    body {
        align-items: normal;
    }
}