a.header-btn {
    padding: 10px 20px;
    background: red;
    color: white;
    font-size: 12px;
    font-weight: 700;
}

.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 9998;
    background: rgba(0, 0, 0, 0.5);
}

.popup {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    padding: 20px;
    box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.2);
    border-radius: 10px;
    text-align: center;
    width: 300px;
}

.popup button {
    display: block;
    width: 100%;
    padding: 10px;
    margin: 5px 0;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
}

.popup h2 {
    margin-bottom: 20px;
}

.popup .book-space {
    background: #28a745;
    color: white;
}

.popup .visitor-reg {
    background: #dc3545;
    color: white;
}

.close-button {
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 18px;
    cursor: pointer;
}