body{
    padding: 0;
    margin: 0;
    user-select: none;
}
#box{
    position: relative;
    width: 420px;
    height: 420px;
    margin: 100px auto;
}
.table{
    width: 100%;
    height: 100%;
}
.table img{
    width: 100%;
    transform: rotate(-30deg);
}
.btn{
    position: absolute;
    left: 50%;
    top:50%;
    margin-left: -75px;
    margin-top:-75px;
    width: 150px;
    height: 150px;
    background-image: url('../img/btn.png');
    background-position: 0 0 ;
    background-size: auto 150px;
}