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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --text-color: #1e293b;
    --text-light: #64748b;
    --bg-color: #ffffff;
    --bg-light: #f8fafc;
    --border-color: #e2e8f0;
    --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: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

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

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

/* Cookie Banner */
.cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--text-color);
    color: white;
    padding: 1rem;
    z-index: 1000;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.cookie-banner.show {
    transform: translateY(0);
}

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

.cookie-content p {
    flex: 1;
    margin: 0;
    font-size: 0.9rem;
}

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

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    font-size: 1.25rem;
}

.nav-menu {
    display: flex;
    gap: 2rem;
    list-style: none;
}

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

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -1.75rem;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

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

/* Hero Section */
.hero {
    padding: 4rem 1rem;
    background: linear-gradient(135deg, var(--bg-light) 0%, white 100%);
    display: flex;
    align-items: center;
    min-height: 500px;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.hero-content p {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

.hero-image img {
    width: 100%;
    height: auto;
    max-width: 500px;
}

/* Books Grid */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

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

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

.book-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.book-content {
    padding: 1.5rem;
}

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

.book-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.book-author {
    color: var(--text-light);
    margin-bottom: 1rem;
    font-style: italic;
}

.book-description {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.book-actions {
    display: flex;
    gap: 1rem;
}

/* Categories */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.category-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    transition: all 0.2s ease;
    text-decoration: none;
    color: var(--text-color);
}

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

.category-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.category-name {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.category-count {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Sections */
.featured-books,
.categories-preview {
    padding: 4rem 1rem;
}

.featured-books {
    background: var(--bg-light);
}

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

/* Search and Filters */
.search-filters {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 3rem;
}

.search-bar {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.search-input {
    flex: 1;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.filter-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background: white;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.9rem;
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Book Detail */
.book-detail {
    padding: 2rem 1rem;
}

.book-detail-content {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 3rem;
}

.book-detail-image {
    width: 100%;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
}

.book-detail-info h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.book-detail-author {
    font-size: 1.25rem;
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 1rem;
}

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

.book-year {
    background: var(--bg-light);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--text-light);
}

.book-description-long {
    margin-bottom: 2rem;
    line-height: 1.7;
    font-size: 1.1rem;
}

.key-takeaways {
    margin-bottom: 2rem;
}

.key-takeaways h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.key-takeaways ul {
    list-style: none;
    padding: 0;
}

.key-takeaways li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.key-takeaways li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.external-links {
    margin-top: 2rem;
}

.external-links h3 {
    margin-bottom: 1rem;
}

.external-links-grid {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.disclaimer-note {
    background: var(--bg-light);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin: 2rem 0;
    font-style: italic;
    color: var(--text-light);
    border-left: 4px solid var(--primary-color);
}

/* Content Pages */
.content-page {
    padding: 2rem 1rem;
    min-height: 60vh;
}

.content-page .container {
    max-width: 800px;
}

.content-page h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.content-page h2 {
    font-size: 1.75rem;
    margin: 2rem 0 1rem 0;
    color: var(--text-color);
}

.content-page p {
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.content-page ul, .content-page ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

.content-page li {
    margin-bottom: 0.5rem;
}

/* Contact Form */
.contact-form {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-color);
}

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

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

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

/* Footer */
.footer {
    background: var(--text-color);
    color: white;
    padding: 3rem 1rem 1rem;
    margin-top: 4rem;
}

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

.footer-section h3 {
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.footer-section p {
    color: #94a3b8;
    line-height: 1.6;
}

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

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

.footer-section ul li a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-section ul li a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #94a3b8;
}

.text-center {
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .books-grid {
        grid-template-columns: 1fr;
    }

    .book-detail-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .search-bar {
        flex-direction: column;
    }

    .filter-buttons {
        justify-content: center;
    }

    .external-links-grid {
        flex-direction: column;
    }

    .cookie-content {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }

    .hero {
        padding: 2rem 0.5rem;
    }

    .hero-content h1 {
        font-size: 1.75rem;
    }

    .featured-books h2,
    .categories-preview h2 {
        font-size: 2rem;
    }

    .categories-grid {
        grid-template-columns: 1fr;
    }
}