body {
    font-family: Arial, sans-serif;
    background-color: white;
    color: black;
    padding: 40px;
    max-width: 800px;
    margin: auto;
    border: 1px solid black;
    padding: 20px;
}
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
}
.modal-content {
    background: white;
    padding: 20px;
    border-radius: 5px;
    text-align: center;
    max-width: 400px;
    border: 1px solid black;
}
.close-btn {
    display: inline-block;
    margin-top: 20px;
    padding: 10px 20px;
    background: black;
    color: white;
    border: none;
    cursor: pointer;
    font-size: 16px;
}