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

:root {
    --primary-color: #2c5aa0;
    --secondary-color: #1e3d72;
    --accent-color: #4a90e2;
    --text-dark: #2d3748;
    --text-light: #4a5568;
    --text-muted: #718096;
    --border-color: #e2e8f0;
    --bg-light: #f7fafc;
    --bg-white: #ffffff;
    --success-color: #48bb78;
    --warning-color: #ed8936;
    --error-color: #f56565;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --border-radius: 8px;
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px 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);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Cookie Banner */
.cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--text-dark);
    color: white;
    padding: 15px 0;
    z-index: 1000;
}

.cookie-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.cookie-content p {
    margin-right: 20px;
    font-size: 14px;
}

.cookie-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 14px;
    white-space: nowrap;
}

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

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

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

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

.logo img {
    margin-right: 10px;
}

.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-btn {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    margin: 2px 0;
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all 0.2s;
    font-size: 1rem;
}

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

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

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

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

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

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

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

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

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

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

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

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

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

.featured-books h2,
.categories-preview h2 {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.section-subtitle {
    text-align: center;
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.section-footer {
    text-align: center;
    margin-top: 3rem;
}

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

.book-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    transition: transform 0.2s, box-shadow 0.2s;
    text-decoration: none;
    color: inherit;
}

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

.book-image {
    text-align: center;
    margin-bottom: 1rem;
}

.book-image img {
    width: 120px;
    height: 160px;
    object-fit: cover;
    border-radius: 4px;
}

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

.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: 4px 8px;
    border-radius: 4px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.book-description {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.5;
}

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

.category-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    text-decoration: none;
    color: inherit;
    transition: transform 0.2s, box-shadow 0.2s;
}

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

.category-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

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

.category-count {
    color: var(--text-muted);
    font-size: 0.875rem;
}

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

.filters-row {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.search-input,
.filter-select {
    padding: 10px 15px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background: var(--bg-white);
}

.search-input {
    flex: 1;
    min-width: 250px;
}

.filter-select {
    min-width: 150px;
}

/* Book Detail */
.book-detail {
    padding: 3rem 0;
}

.book-detail-container {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 3rem;
    align-items: start;
}

.book-detail-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.book-detail-content h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.book-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.meta-item {
    display: flex;
    flex-direction: column;
}

.meta-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

.meta-value {
    font-size: 1rem;
    color: var(--text-dark);
    font-weight: 600;
}

.book-description {
    margin-bottom: 2rem;
}

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

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

.key-takeaways li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-light);
}

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

.external-links {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-top: 2rem;
}

.external-links h3 {
    margin-bottom: 1rem;
    color: var(--text-dark);
}

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

.external-link {
    display: inline-block;
    padding: 10px 20px;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: background-color 0.2s;
}

.external-link:hover {
    background: var(--secondary-color);
}

.disclaimer-note {
    background: var(--warning-color);
    color: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-top: 1rem;
    font-size: 0.95rem;
}

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

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

.form-input,
.form-textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(44, 90, 160, 0.1);
}

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

/* Content Pages */
.content-page {
    padding: 3rem 0;
}

.content-header {
    text-align: center;
    margin-bottom: 3rem;
}

.content-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.content-body {
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
}

.content-body h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin: 2rem 0 1rem;
    color: var(--text-dark);
}

.content-body h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 1.5rem 0 1rem;
    color: var(--text-dark);
}

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

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

.content-body li {
    margin-bottom: 0.5rem;
    color: var(--text-light);
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    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-logo {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    font-weight: 600;
    font-size: 1.125rem;
}

.footer-logo img {
    margin-right: 10px;
}

.footer-section h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

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

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

.footer-section a {
    color: #cbd5e0;
    text-decoration: none;
    transition: color 0.2s;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #4a5568;
    color: #a0aec0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }

    .nav {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero .container {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

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

    .hero-actions {
        justify-content: center;
        flex-wrap: wrap;
    }

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

    .categories-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }

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

    .filters-row {
        flex-direction: column;
        align-items: stretch;
    }

    .search-input {
        min-width: auto;
    }

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

    .cookie-content {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .cookie-content p {
        margin-right: 0;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 1.75rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

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

    .book-card {
        padding: 1rem;
    }

    .category-card {
        padding: 1.5rem;
    }
}