/* Reset some default styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f4f4f4;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background-color: #3498db;
    color: #fff;
    text-align: center;
    padding: 1rem;
    margin-bottom: 2rem;
}

h1 {
    font-size: 2.5rem;
}

main {
    background-color: #fff;
    padding: 2rem;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: bold;
}

select {
    width: 100%;
    padding: 0.5rem;
    font-size: 1rem;
    border: 1px solid #ccc;
    border-radius: 3px;
}

.btn {
    display: inline-block;
    background-color: #3498db;
    color: #fff;
    padding: 0.7rem 1.5rem;
    border: none;
    border-radius: 3px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #2980b9;
}

footer {
    text-align: center;
    margin-top: 2rem;
    color: #777;
}

footer p {
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

/* Responsive design */
@media (max-width: 600px) {
    .container {
        padding: 10px;
    }

    main {
        padding: 1rem;
    }

    h1 {
        font-size: 2rem;
    }
}

#downloadMessage {
    color: #3498db;
    font-style: italic;
}

#chapterRange {
    margin-top: 10px;
}

#chapterRange input[type="number"] {
    width: 60px;
    padding: 5px;
    margin-right: 10px;
}