#exit-popup {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 9999;
}

.popup-overlay {
    position: absolute;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.6);
}

.popup-content {
    position: relative;
    max-width: 400px;
    margin: 10% auto;
    background: #fff;
    padding: 20px;
    text-align: center;
    border-radius: 8px;
}

.join-btn {
    display: inline-block;
    padding: 10px 20px;
    background: #25D366;
    color: #fff;
    text-decoration: none;
    border-radius: 5px;
    margin-top: 10px;
}

.close-popup {
    display: block;
    margin-top: 10px;
    background: none;
    border: none;
    color: #888;
    cursor: pointer;
}