.popup {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 20px;
    background: #fff;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    border-radius: 8px;
    z-index: 1000;
}

.popup.visible {
    display: block;
}

.popup .close-btn {
    background: #d9534f;
    color: #fff;
    border: none;
    padding: 5px 10px;
    cursor: pointer;
    border-radius: 4px;
    margin-top: 10px;
}

.popup .close-btn:hover {
    background: #c9302c;
}

/* Optional: Background overlay */
.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
}

.overlay.visible {
    display: block;
}