body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #f5f5f5;
    color: #333;
}

header {
    background-color: #4CAF50;
    color: white;
    padding: 15px;
    text-align: center;
}

header .logo {
    width: 80px;
}

nav button {
    margin: 0 5px;
    padding: 5px 10px;
    cursor: pointer;
}

main {
    padding: 20px;
}

section {
    background: white;
    margin-bottom: 20px;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 5px rgba(0,0,0,0.1);
}

#chat-box {
    height: 300px;
    border: 1px solid #ccc;
    padding: 10px;
    overflow-y: auto;
    margin-bottom: 10px;
}

.books-grid {
    display: flex;
    gap: 10px;
}

.book-item {
    background: #4CAF50;
    color: white;
    padding: 10px;
    border-radius: 5px;
    flex: 1;
    text-align: center;
}

footer {
    text-align: center;
    padding: 15px;
    background: #333;
    color: white;
}