body{
    background-color: burlywood;
    background: url(images/bonneteau_bg.jpg);
    margin: 10px;
    
}
div{
    width: 100%;
    height: 100%;
}


main,header{
    display: flex;
    justify-content: center;
    align-items: center;
}
p{
    color: white;
    font-size: 30px;
}
h1{
    color: white;
    font-size: 50px;
    display: flex;
    justify-content: center;
}
div.cards{
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
    margin: 10%;
    perspective: 1000px;
}
div.card-item{
    transition: 1s;
    width: 200px;
    height: 300px;
    margin: 10px;
    transform-style: preserve-3d;
}
.front,.back{
position: absolute;
backface-visibility: hidden;
height: 300px;


}
.front{
    background: url(images/black.png) no-repeat;
    background-size: 200px;
    width: 200px;
    transform: rotateY(180deg);
    
}
.back:hover{
    transition: 0.3s;
    box-shadow: 0px 0px 20px 3px #fff;
}
.back{
    background: url(images/dos.png) ;
    background-size: 200px;
    width: 200px;
    
}

span.button#btn{
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 10%;
    
    
}
button#btn{
    font-size: 50px;
   
}
button#btn:hover{
    box-shadow: 5px 5px 5px 5px black;
}
footer{
    color: white;
    text-align: center;
    
}