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

:root {
    --primary-color: hsl(67, 70%, 50%);
    --primary-dark: hsl(67, 70%, 40%);
    --secondary-color: hsl(210, 15%, 25%);
    --text-color: hsl(210, 15%, 20%);
    --text-muted: hsl(210, 10%, 50%);
    --background-color: hsl(0, 0%, 100%);
    --background-light: hsl(210, 20%, 98%);
    --border-color: hsl(210, 15%, 90%);
    --shadow: 0 2px 10px hsla(210, 15%, 25%, 0.1);
    --shadow-hover: 0 4px 20px hsla(210, 15%, 25%, 0.15);
    --border-radius: 8px;
    --max-width: 1200px;
    --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(--background-color);
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

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

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

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

.logo img {
    width: 32px;
    height: 32px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
}

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

.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    padding: 80px 20px;
    background: linear-gradient(135deg, var(--background-light) 0%, var(--background-color) 100%);
    display: flex;
    align-items: center;
    min-height: 60vh;
    max-width: var(--max-width);
    margin: 0 auto;
    gap: 60px;
}

.hero-content {
    flex: 1;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 30px;
    max-width: 500px;
}

.hero-image {
    flex: 1;
    text-align: center;
}

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

/* Buttons */
.btn-primary {
    display: inline-block;
    background: var(--primary-color);
    color: var(--text-color);
    padding: 12px 24px;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.btn-secondary {
    display: inline-block;
    background: transparent;
    color: var(--text-color);
    padding: 12px 24px;
    text-decoration: none;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: all 0.3s ease;
}

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

/* Sections */
.featured-section,
.categories-section {
    padding: 80px 0;
}

.categories-section {
    background: var(--background-light);
}

.featured-section h2,
.categories-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    font-weight: 700;
}

/* Books Grid */
.books-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.book-card {
    background: var(--background-color);
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
}

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

.book-cover {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
}

.book-card h3 {
    font-size: 1.3rem;
    margin-bottom: 8px;
    font-weight: 600;
}

.book-author {
    color: var(--text-muted);
    margin-bottom: 12px;
    font-style: italic;
}

.book-category {
    display: inline-block;
    background: var(--primary-color);
    color: var(--text-color);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 12px;
}

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

/* Categories Grid */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.category-card {
    background: var(--background-color);
    padding: 30px;
    border-radius: var(--border-radius);
    text-decoration: none;
    color: inherit;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    text-align: center;
}

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

.category-card h3 {
    font-size: 1.4rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.category-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Book Detail Page */
.book-detail {
    padding: 40px 0;
}

.book-detail-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 50px;
    margin-bottom: 40px;
}

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

.book-detail-info h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.book-detail-author {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 15px;
    font-style: italic;
}

.book-detail-meta {
    display: flex;
    gap: 20px;
    margin-bottom: 25px;
    flex-wrap: wrap;
}

.book-detail-category {
    background: var(--primary-color);
    color: var(--text-color);
    padding: 6px 16px;
    border-radius: 20px;
    font-weight: 500;
}

.book-detail-year {
    background: var(--background-light);
    color: var(--text-muted);
    padding: 6px 16px;
    border-radius: 20px;
    font-weight: 500;
}

.book-description-long {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: 30px;
    color: var(--text-color);
}

.book-takeaways {
    margin-bottom: 30px;
}

.book-takeaways h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

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

.book-takeaways li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: var(--text-color);
}

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

.book-for {
    background: var(--background-light);
    padding: 20px;
    border-radius: var(--border-radius);
    margin-bottom: 30px;
}

.book-for h3 {
    margin-bottom: 10px;
    color: var(--text-color);
}

.external-links {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.external-links a {
    padding: 10px 20px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: all 0.3s ease;
}

.external-links a:hover {
    border-color: var(--primary-color);
    background: var(--primary-color);
}

.disclaimer-note {
    background: var(--background-light);
    border-left: 4px solid var(--primary-color);
    padding: 15px 20px;
    margin: 30px 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.disclaimer-note p {
    margin: 0;
    color: var(--text-muted);
    font-style: italic;
}

/* Search and Filter */
.search-filter {
    background: var(--background-light);
    padding: 30px;
    border-radius: var(--border-radius);
    margin-bottom: 40px;
}

.search-filter-row {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    align-items: center;
}

.search-input {
    flex: 1;
    min-width: 250px;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

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

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

.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Forms */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
    color: var(--text-color);
}

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

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

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

/* Cookie Banner */
.cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--secondary-color);
    color: white;
    padding: 20px;
    z-index: 1000;
    box-shadow: 0 -2px 10px hsla(210, 15%, 25%, 0.2);
}

.cookie-content {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
}

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

/* Footer */
.footer {
    background: var(--secondary-color);
    color: white;
    padding: 50px 0 20px;
    margin-top: 80px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 15px;
    color: var(--primary-color);
}

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

.footer-section ul li {
    margin-bottom: 8px;
}

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

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

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid hsla(0, 0%, 100%, 0.1);
    color: hsla(0, 0%, 100%, 0.7);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--background-color);
        border-top: 1px solid var(--border-color);
        flex-direction: column;
        padding: 20px;
        gap: 10px;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

    .hero {
        flex-direction: column;
        text-align: center;
        padding: 60px 20px;
        gap: 40px;
    }

    .hero-content h1 {
        font-size: 2.2rem;
    }

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

    .book-detail-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

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

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

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

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

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 1.8rem;
    }

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

    .book-detail-info h1 {
        font-size: 2rem;
    }

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

/* Utility Classes */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mb-20 { margin-bottom: 20px; }
.mb-30 { margin-bottom: 30px; }
.mt-20 { margin-top: 20px; }
.mt-30 { margin-top: 30px; }