body, html{
    height: 100%;
}

.display-1{
    font-weight: 400;
}
#startScreen{
    background-color: pink;
    height: 100%;
}

#playground{
    background-color: rgba(19, 69, 143, 0.886);
}

#menu{
    font-size: 1em;
    width: 100px;
    height: 100%;
}

#cl{
    font-size: 4em;
}
.jumbotron{
    border-radius: 30px;
    color: rgb(42, 140, 193);
}

.space{
    margin: 20px;
}
.dashboard{
    display: block;
    border: pink solid 1px;
}

.pair12{
    width: 11.5%;
}

.pair6{
    width: 16%;
}

.cards{
    margin: auto auto;
    perspective: 600px;
    background-color: transparent;
}

.card-inner{
    position: relative;
    width: 100%;
    height: 190px;
    transform: matrix(1, 0, 0, 1, 0, 0);
    transform-style: preserve-3d;
    transition: transform 1s, opacity 1s, visibility 1s;
    background-color: transparent;
    
}
.card-front, .card-back{
    border-radius: 20px;
    position: absolute;
    width: 100%;
    height: 100%;
    box-shadow:  2px 3px 5px rgba(0,0,0,0.3);
    backface-visibility: hidden;
}

.card-front{
    background-color: black;
} 

.card-back{
    background-color: white;
    transform: rotateY(180deg);
    font-size: 6em;
}

.rotate{
    transform: rotateY(180deg);
}
.nums{
    line-height: 190px; 
    text-align: center;
    vertical-align: middle;
}
.win{
    width: 1000px;
    height: 300px;
    line-height: 150px;
    vertical-align: middle;
    font-size: 6rem;
    font-weight: 500;
    margin: auto auto;
    background-color: yellow;
}