body {
    font-family: Arial, sans-serif;
    background-color: #f9f9f9;
    margin: 0;
    padding: 0;
}

.pdf-viewer {
    border: 1px solid #ddd;
    padding: 10px;
    background-color: #fff;
}

button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 10px;
    cursor: pointer;
}

button:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}