@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600;700&display=swap');
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif, 'Quicksand';
}
body{
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    /* background: #6563ff; */
    background-color: #21D4FD;
    background-image: linear-gradient(45deg, #21d4fd 0%, #b721ff 100%);
}
.wrapper{
    height: 400px;
    width: 400px;
    padding: 25px;
    background: #f8f8f8;
    border-radius: 10px;
    box-shadow: 18px 18px 36px #0e0707 ;
}
.cards, .card, .view{
    display: flex;
    align-items: center;
    justify-content: center;
}
.cards{
    height: 100%;
    width: 100%;
    flex-wrap: wrap;
    justify-content: space-between;
}
.cards .card{
    cursor: pointer;
    position: relative;
    perspective: 800px;
    transform-style: preserve-3d;
    height: calc(100% / 4 - 10px);
    width: calc(100% / 4 - 10px);
}
.card.shake{
    animation: shake 0.35s ease-in-out;
}
@keyframes shake {
    0%, 100%{
        transform: translateX(0);
    }
    20%{
        transform: translateX(-13px);
    }
    40%{
        transform: translateX(13px);
    }
    60%{
        transform: translateX(-8px);
    }
    80%{
        transform: translateX(8px);
    }
}
.cards .card .view{
    width: 100%;
    height: 100%;
    user-select: none;
    pointer-events: none;
    position: absolute;
    background: #fff;
    border-radius: 7px;
    backface-visibility: hidden;
    transition: transform 0.25s linear;
    box-shadow: 10px 3px 10px rgba(0,0,0,0.3);
}
.card.right {
    box-shadow: 2px 2px 10px rgb(43, 255, 0);
    border: 3px solid rgb(43, 255, 0);
}

.card.done .view{
    box-shadow: 0 3px 10px rgba(0,0,0,0.3);
    border: 3px solid rgba(0,0,0,0.3);
}
.card .front-view span{
    color: #6563ff;
    font-size: 40px;
}

.card .back-view{
    transform: rotateY(-180deg);
}
.card .back-view img{
    max-width: 45px;
}

.card.flip .front-view{
    transform: rotateY(180deg);
}
.card.flip .back-view{
    transform: rotateY(0);
}
footer{
    position: absolute;
    top: 94%;
    background: #0e0707;
    display: inline-block;
    color: rgb(0, 255, 0);
    width: 100%;
    padding-top: 5px;
    text-align: center;
}