* {
    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 5px 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 */
.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 a {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo img {
    width: 40px;
    height: 40px;
    margin-right: 12px;
}

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

.nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
}

.nav a:hover,
.nav a.active {
    color: var(--secondary-color);
    border-bottom-color: var(--secondary-color);
}

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

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

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

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

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

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

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--border-color);
    padding: 8px 16px;
    font-size: 0.9rem;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 4rem 0;
}

.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: 1.5rem;
    line-height: 1.2;
}

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

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

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

/* Section Styling */
section {
    padding: 4rem 0;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 3rem;
}

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

h2 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

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

.book-card {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
}

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

.book-image {
    height: 200px;
    overflow: hidden;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.book-content {
    padding: 1.5rem;
}

.book-category {
    background: var(--secondary-color);
    color: var(--white);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 1rem;
}

.book-content h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.book-content h3 a {
    text-decoration: none;
    color: var(--primary-color);
    transition: var(--transition);
}

.book-content h3 a:hover {
    color: var(--secondary-color);
}

.book-author {
    color: var(--text-light);
    font-weight: 600;
    margin-bottom: 1rem;
}

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

/* Categories */
.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(-5px);
    box-shadow: var(--shadow-hover);
}

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

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

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

.category-link:hover {
    text-decoration: underline;
}

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

.search-form {
    display: flex;
    gap: 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.search-input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

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

.filter-select {
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background: var(--white);
    min-width: 150px;
}

/* Book Details */
.book-details {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    align-items: start;
}

.book-details-image {
    background: var(--bg-light);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
}

.book-details-image img {
    width: 100%;
    max-width: 300px;
    height: auto;
}

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

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

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

.meta-label {
    font-weight: 600;
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.meta-value {
    font-weight: 700;
    color: var(--primary-color);
}

.book-description {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.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: "✓";
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

.external-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

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

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

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

.form-input,
.form-textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
}

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

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

/* Contact Info */
.contact-info {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
}

.contact-item:last-child {
    margin-bottom: 0;
}

.contact-icon {
    width: 20px;
    height: 20px;
    margin-right: 12px;
    color: var(--secondary-color);
}

/* 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-logo {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
}

.footer-logo img {
    width: 32px;
    height: 32px;
    margin-right: 10px;
    filter: brightness(0) invert(1);
}

.footer-logo span {
    font-weight: 700;
    font-size: 1.1rem;
}

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

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

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

/* Cookie Notice */
.cookie-notice {
    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-notice.show {
    transform: translateY(0);
}

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

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

.cookie-btn {
    background: var(--secondary-color);
    color: var(--white);
    border: none;
    padding: 8px 16px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.cookie-btn:hover {
    background: #2980b9;
}

/* Responsive Design */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }

    .nav {
        display: none;
    }

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

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

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

    .book-meta {
        gap: 1rem;
    }

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

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

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

    h2 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 2rem 0;
    }

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

    section {
        padding: 2rem 0;
    }

    .book-card,
    .category-card {
        margin: 0 -5px;
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .cookie-notice,
    .external-links {
        display: none;
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
    }

    .container {
        max-width: none;
        padding: 0;
    }
}