body {
    font-family: Arial, sans-serif;
    text-align: center;
    padding: 40px;
}
input {
    padding: 10px;
    font-size: 16px;
    margin: 10px;
}
button {
    padding: 10px 20px;
    font-size: 16px;
}
.ad-popup {
    display: none;
    position: relative;
}
#adPopup img {
    width: 100%;
    max-width: 300px;
}
#countdown {
    font-size: 24px;
    color: red;
    margin-top: 10px;
}