.popup {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    height: 700px;
    border: 1px solid #000;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
    z-index: 1000;
}
.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    z-index: 999;
}
.close-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background: red;
    color: white;
    border: none;
    padding: 5px 10px;
    cursor: pointer;
}