body {
    background-image: url("../images/jocs_de_taula.jpg");
    background-repeat: no-repeat;
    background-size: auto;
}
.principal {
    width: 350px;
    height: 350px;
    margin: 0 auto;
    margin-top: 30px;
    font-family: arial;
    font-size: 12px;
    margin-top: 100px;
    text-align: center;
}
.boton {
    width: 100px;
    height: 100px;
    margin: 1px;
    color: white;
    background-color: black;
    border: 2px solid #3e3b32;
    border-radius: 5px;
    font-size: 50px;
    cursor: pointer;
}