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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

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

/* Header */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #2c5aa0;
    font-weight: 700;
    font-size: 1.25rem;
    gap: 10px;
}

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

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #2c5aa0;
}

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

.btn-primary {
    background: #2c5aa0;
    color: white;
}

.btn-primary:hover {
    background: #1e3f73;
}

.btn-outline {
    background: transparent;
    color: #2c5aa0;
    border: 2px solid #2c5aa0;
}

.btn-outline:hover {
    background: #2c5aa0;
    color: white;
}

.btn-large {
    padding: 16px 32px;
    font-size: 18px;
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 60vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.1;
    z-index: 1;
}

.hero-bg-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 600px;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    color: #1a202c;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero p {
    font-size: 1.25rem;
    color: #4a5568;
    margin-bottom: 2rem;
}

/* Sections */
section {
    padding: 4rem 0;
}

.section-subtitle {
    font-size: 1.125rem;
    color: #6b7280;
    margin-bottom: 2rem;
    text-align: center;
}

h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1a202c;
    margin-bottom: 1rem;
    text-align: center;
}

/* Books Grid */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.book-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-decoration: none;
    color: inherit;
}

.book-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.book-image {
    width: 100%;
    height: 200px;
    object-fit: contain;
    border-radius: 8px;
    margin-bottom: 1rem;
    background: #f8fafc;
}

.book-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1a202c;
    margin-bottom: 0.5rem;
}

.book-author {
    color: #6b7280;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.book-category {
    display: inline-block;
    background: #e2e8f0;
    color: #2c5aa0;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.book-description {
    color: #4a5568;
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Categories Grid */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.category-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
    text-decoration: none;
    color: inherit;
}

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

.category-card h3 {
    font-size: 1.5rem;
    color: #2c5aa0;
    margin-bottom: 1rem;
}

.category-count {
    color: #6b7280;
    font-size: 0.9rem;
}

/* Search and Filters */
.search-filters {
    background: #f8fafc;
    padding: 2rem 0;
    margin-bottom: 2rem;
}

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

.search-input {
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 6px;
    font-size: 16px;
    min-width: 300px;
    outline: none;
    transition: border-color 0.3s ease;
}

.search-input:focus {
    border-color: #2c5aa0;
}

.filter-select {
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 6px;
    font-size: 16px;
    background: white;
    outline: none;
    cursor: pointer;
}

/* Book Details */
.book-detail {
    max-width: 800px;
    margin: 2rem auto;
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.book-detail-header {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.book-detail-image {
    width: 100%;
    height: 300px;
    object-fit: contain;
    border-radius: 8px;
    background: #f8fafc;
}

.book-detail-info h1 {
    font-size: 2rem;
    color: #1a202c;
    margin-bottom: 0.5rem;
}

.book-detail-author {
    font-size: 1.125rem;
    color: #6b7280;
    margin-bottom: 1rem;
}

.book-year {
    color: #9ca3af;
    margin-bottom: 1rem;
}

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

.external-link {
    padding: 8px 16px;
    background: #2c5aa0;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-size: 0.9rem;
    transition: background 0.3s ease;
}

.external-link:hover {
    background: #1e3f73;
}

.book-section {
    margin: 2rem 0;
}

.book-section h3 {
    font-size: 1.5rem;
    color: #1a202c;
    margin-bottom: 1rem;
}

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

.key-takeaways li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #e2e8f0;
    position: relative;
    padding-left: 1.5rem;
}

.key-takeaways li:before {
    content: "•";
    color: #2c5aa0;
    font-weight: bold;
    position: absolute;
    left: 0;
}

.disclaimer-note {
    background: #fef3cd;
    border: 1px solid #fbbf24;
    border-radius: 6px;
    padding: 1rem;
    margin: 2rem 0;
    font-size: 0.9rem;
    color: #92400e;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #374151;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 6px;
    font-size: 16px;
    outline: none;
    transition: border-color 0.3s ease;
}

.form-control:focus {
    border-color: #2c5aa0;
}

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

/* Cookie Banner */
.cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: #1a202c;
    color: white;
    padding: 1rem;
    z-index: 10000;
    box-shadow: 0 -4px 20px rgba(0,0,0,0.3);
}

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

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

/* Footer */
.footer {
    background: #1a202c;
    color: 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 {
    color: white;
    margin-bottom: 1rem;
}

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

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

.footer-section a {
    color: #cbd5e0;
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #9ca3af;
}

/* Utilities */
.text-center {
    text-align: center;
}

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

.mb-2 {
    margin-bottom: 1rem;
}

.mt-2 {
    margin-top: 1rem;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0,0,0,0.05);
        padding: 2rem 0;
    }

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

    .nav-toggle {
        display: flex;
    }

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

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

    h2 {
        font-size: 2rem;
    }

    .search-container {
        flex-direction: column;
        align-items: stretch;
    }

    .search-input {
        min-width: auto;
        width: 100%;
    }

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

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

    .external-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
    
    .categories-grid {
        grid-template-columns: 1fr;
    }
}