/* Popup container */
    .popup {
        display: none;
        position: fixed;
        top: 20%;
        left: 50%;
        transform: translateX(-50%);
        padding: 20px;
        background-color: #fff;
        border: 2px solid #333;
        box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
        text-align: center;
        font-size: 16px;
        z-index: 9999;
    }

    /* Popup button */
    .popup button {
        margin-top: 20px;
        padding: 10px 20px;
        background-color: #333;
        color: #fff;
        border: none;
        cursor: pointer;
        font-size: 14px;
    }

    .popup button:hover {
        background-color: #444;
    }