* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --text-color: #1e293b;
    --text-light: #64748b;
    --border-color: #e2e8f0;
    --bg-light: #f8fafc;
    --white: #ffffff;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --border-radius: 8px;
    --font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
.header {
    background: var(--white);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-color);
    text-decoration: none;
}

.logo a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: inherit;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-light);
    font-weight: 500;
    transition: color 0.2s;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-toggle span {
    width: 20px;
    height: 2px;
    background: var(--text-color);
    transition: all 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--bg-light) 0%, var(--white) 100%);
    padding: 4rem 0;
    text-align: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary-color);
    color: var(--white);
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: var(--white);
}

/* Sections */
.featured-books,
.categories-preview {
    padding: 4rem 0;
}

.featured-books h2,
.categories-preview h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
}

/* Books Grid */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.book-card {
    background: var(--white);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid var(--border-color);
}

.book-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.book-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
}

.book-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.book-author {
    color: var(--text-light);
    margin-bottom: 0.5rem;
    font-style: italic;
}

.book-category {
    display: inline-block;
    background: var(--bg-light);
    color: var(--primary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.book-description {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.5;
}

.book-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Categories Grid */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.category-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.category-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.category-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.category-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.category-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

.category-link:hover {
    color: #1d4ed8;
}

/* Search and Filter */
.search-filters {
    background: var(--bg-light);
    padding: 2rem 0;
    margin-bottom: 2rem;
}

.search-form {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    align-items: center;
}

.search-input,
.filter-select {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    min-width: 200px;
}

.search-input:focus,
.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Book Detail Page */
.book-detail {
    padding: 2rem 0;
}

.book-detail-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.book-detail-image {
    width: 100%;
    height: 400px;
    object-fit: cover;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.book-meta h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.book-meta .book-author {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.book-meta .book-category {
    margin-bottom: 1.5rem;
}

.book-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.external-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--accent-color);
    color: var(--white);
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: background 0.2s;
}

.external-link:hover {
    background: #d97706;
}

.book-sections {
    display: grid;
    gap: 2rem;
}

.book-section {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
}

.book-section h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.takeaways-list {
    list-style: none;
}

.takeaways-list li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.5rem;
}

.takeaways-list li::before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.disclaimer-notice {
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    margin-top: 2rem;
    font-style: italic;
    color: var(--text-light);
}

/* Contact Form */
.contact-form {
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: inherit;
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Footer */
.footer {
    background: var(--bg-light);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--text-light);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-section ul li a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
    text-align: center;
    color: var(--text-light);
}

/* Cookie Banner */
.cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--text-color);
    color: var(--white);
    padding: 1rem;
    z-index: 1000;
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
}

.cookie-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    max-width: 1200px;
    margin: 0 auto;
    flex-wrap: wrap;
}

.cookie-content p {
    margin: 0;
    flex: 1;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .hero-content h1 {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
    
    .categories-grid {
        grid-template-columns: 1fr;
    }
    
    .book-detail-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .book-detail-image {
        height: 300px;
        max-width: 200px;
        margin: 0 auto;
    }
    
    .search-form {
        flex-direction: column;
        align-items: stretch;
    }
    
    .search-input,
    .filter-select {
        min-width: auto;
    }
    
    .cookie-content {
        flex-direction: column;
        text-align: center;
    }
    
    .book-links {
        justify-content: center;
    }
    
    .external-link {
        flex: 1;
        justify-content: center;
        min-width: 150px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.75rem;
    }
    
    .hero {
        padding: 2rem 0;
    }
    
    .featured-books,
    .categories-preview {
        padding: 2rem 0;
    }
    
    .book-card,
    .category-card,
    .book-section {
        padding: 1rem;
    }
    
    .book-meta h1 {
        font-size: 2rem;
    }
    
    .hero-actions {
        gap: 0.5rem;
    }
    
    .btn {
        padding: 0.625rem 1.25rem;
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .cookie-banner,
    .book-links,
    .hero-actions {
        display: none;
    }
    
    .book-detail-content {
        grid-template-columns: 1fr;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
    
    h1 { font-size: 18pt; }
    h2 { font-size: 16pt; }
    h3 { font-size: 14pt; }
}