body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 10px;
}

main {
    padding: 20px;
}

.product {
    border: 1px solid #ccc;
    padding: 10px;
    margin-bottom: 10px;
    cursor: pointer;
}

#buyCreditsBtn {
    background-color: #4caf50;
    color: #fff;
    padding: 10px;
    cursor: pointer;
}