#pexeso {
    width: 600px;
}
#x-zero {
    width: 400px;
}
.card div {
    width: 100px;
    height: 100px;
    float: left;
    margin: 10px;
    border: 1px solid black;
    background-color: #5bc0de;
}
.card div p {
    width: 100%;
    height: 100%;
    margin: 0;
    display: flex;
}
.card div p span {
    margin: auto;
    font-size: large;
}
.visible {
    visibility: visible;
}
.hidden {
    visibility: hidden;
}
.matched {
    background-color: #fcf8e3;
}