.popup {
    display: none; /* Ẩn popup lúc ban đầu */
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.popup-content {
    background-color: white;
    margin: 15% auto;
    padding: 20px;
    width: 80%;
    max-width: 550px;
    text-align: center;
    border-radius: 10px;
}

.close-popup {
    color: black;
    float: right;
    font-size: 30px;
    cursor: pointer;
}

p.custom-message {
    color: #ff6600;
    font-weight: bold;
    font-size: 28px;
    margin: 15px;
}

.popup h2{
    font-size: 24px;
}