body {
    background-color: #f4f6f9;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: #333;
}

/* Navbar Branding */
.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    letter-spacing: 0.5px;
}

/* Book Card Styling */
.card {
    border: none;
    border-radius: 12px;
    background-color: #fff;
    transition: box-shadow 0.3s ease;
}

.card:hover {
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.book-cover {
    border-top-left-radius: 12px;
    border-top-right-radius: 12px;
    transition: transform 0.3s ease;
}

.book-cover:hover {
    transform: scale(1.03);
}

.card-title {
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.card-text.text-primary {
    color: #0d6efd !important;
    font-size: 1.1rem;
}

/* Buttons */
.btn-primary {
    background-color: #0d6efd;
    border-color: #0d6efd;
    font-weight: 500;
}

.btn-primary:hover {
    background-color: #0b5ed7;
    border-color: #0a58ca;
}

.btn-success {
    background-color: #25D366; /* WhatsApp Color */
    border-color: #25D366;
    font-weight: 500;
}

.btn-success:hover {
    background-color: #128C7E;
    border-color: #128C7E;
}

/* Footer */
footer {
    background-color: #fff !important;
    border-top: 1px solid #e9ecef;
    color: #6c757d;
}

footer p {
    margin-bottom: 0.5rem;
}

footer .small {
    font-size: 0.85rem;
}

/* Detail Page */
h1 {
    font-weight: 700;
    color: #2c3e50;
}

.lead {
    font-size: 1.1rem;
    line-height: 1.6;
    color: #555;
}

.list-group-item {
    background-color: transparent;
    border-color: #e9ecef;
    padding: 0.75rem 0;
}

.list-group-item strong {
    color: #2c3e50;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .navbar-brand {
        font-size: 1.25rem;
    }
    
    .card-img-top {
        height: 250px;
    }
}