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

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --text-light: #666;
    --border-color: #ddd;
    --bg-light: #f8f9fa;
    --white: #ffffff;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 20px rgba(0,0,0,0.15);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

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

/* Header & Navigation */
.header {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1.2rem;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 0;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--secondary-color);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    margin: 3px 0;
    transition: var(--transition);
}

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

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

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

/* Buttons */
.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background: var(--white);
    color: var(--secondary-color);
    border: 2px solid var(--secondary-color);
}

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

/* Books Grid */
.featured-books,
.books-section {
    padding: 4rem 0;
}

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

.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);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
    text-decoration: none;
    color: inherit;
}

.book-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.book-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: var(--bg-light);
}

.book-content {
    padding: 1.5rem;
}

.book-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

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

.book-category {
    display: inline-block;
    background: var(--secondary-color);
    color: var(--white);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    margin-bottom: 1rem;
}

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

/* Categories */
.categories-preview {
    padding: 4rem 0;
    background: var(--bg-light);
}

.categories-preview h2 {
    text-align: center;
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 3rem;
}

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

.category-card {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.category-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

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

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

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

.search-filter .container {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 1rem;
    align-items: center;
}

.search-input,
.filter-select {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.search-input:focus,
.filter-select:focus {
    outline: none;
    border-color: var(--secondary-color);
}

/* Book Detail */
.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);
    background: var(--bg-light);
}

.book-detail-info h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.book-detail-meta {
    margin-bottom: 2rem;
}

.book-detail-meta p {
    margin-bottom: 0.5rem;
    color: var(--text-light);
}

.book-links {
    display: flex;
    gap: 1rem;
    margin: 2rem 0;
}

.book-links a {
    padding: 0.5rem 1rem;
    background: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.book-links a:hover {
    background: #2980b9;
}

.key-takeaways,
.who-its-for {
    margin-bottom: 2rem;
}

.key-takeaways h3,
.who-its-for h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

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

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

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

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

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

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

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

/* Footer */
.footer {
    background: var(--primary-color);
    color: var(--white);
    padding: 3rem 0 1rem;
}

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--white);
}

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

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

.footer-section a {
    color: #bdc3c7;
    text-decoration: none;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #34495e;
    color: #bdc3c7;
}

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

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

.cookie-banner.hidden {
    display: none;
}

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

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

/* Page Content */
.page-content {
    padding: 2rem 0;
    min-height: 60vh;
}

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

.page-content h2 {
    color: var(--primary-color);
    margin: 2rem 0 1rem;
}

.page-content p {
    margin-bottom: 1rem;
    line-height: 1.6;
}

.page-content ul {
    margin-bottom: 1rem;
    padding-left: 2rem;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        transition: var(--transition);
        box-shadow: var(--shadow);
        padding: 2rem 0;
        gap: 1rem;
    }

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

    .nav-toggle {
        display: flex;
    }

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

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

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

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

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

    .search-filter .container {
        grid-template-columns: 1fr;
    }

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

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

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-content h1 {
        font-size: 1.8rem;
    }
    
    .book-links {
        flex-direction: column;
    }
}