/* Basic layout */
body{
    font-family: Arial;
    text-align: center;
    background: #f7f7f7;
}
#game{
    width: 450px;
    margin: auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}
.card{
    width: 100px;
    height: 100px;
    background: #333;
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 45px;
    color: white;
    cursor: pointer;
}
.card.open{
    background: #4caf50;
}
.card.matched{
    background: #2196f3;
    cursor: default;
}