/* CSS Variables */
:root {
    --color-primary: #E8E030; /* Yellow from logo */
    --color-primary-dark: #d4cc2a;
    --color-dark: #1a1a1a;
    --color-text: #333333;
    --color-text-light: #666666;
    --color-white: #ffffff;
    --color-cream: #faf9f6;
    --color-amazon: #ff9900;
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Open Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);
    --transition: all 0.3s ease;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-white);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* Typography */
h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
}

h3 {
    font-size: clamp(1.25rem, 2vw, 1.5rem);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

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

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

.btn-amazon {
    background-color: var(--color-amazon);
    color: var(--color-dark);
}

.btn-amazon:hover {
    background-color: #e68a00;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-large {
    padding: 18px 36px;
    font-size: 1.125rem;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: var(--color-white);
    box-shadow: var(--shadow-sm);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 20px;
}

.logo img {
    height: 50px;
    width: auto;
}

.nav-links {
    display: flex;
    gap: 40px;
}

.nav-links a {
    font-weight: 500;
    color: var(--color-text);
    position: relative;
    padding: 5px 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

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

.mobile-menu-btn span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--color-dark);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, var(--color-cream) 0%, var(--color-white) 100%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-text h1 {
    margin-bottom: 24px;
    color: var(--color-dark);
}

.highlight {
    color: var(--color-dark);
    background: linear-gradient(180deg, transparent 60%, var(--color-primary) 60%);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-light);
    margin-bottom: 32px;
}

.hero-image {
    position: relative;
}

.hero-image img {
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
}

/* Books Section */
.books {
    padding: 100px 0;
    background-color: var(--color-white);
}

.section-title {
    text-align: center;
    margin-bottom: 16px;
    color: var(--color-dark);
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-light);
    font-size: 1.125rem;
    margin-bottom: 60px;
}

.books-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.book-card {
    background: var(--color-white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.book-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.book-cover {
    position: relative;
    aspect-ratio: 3/4;
    background: linear-gradient(135deg, #f0f0f0 0%, #e0e0e0 100%);
    overflow: hidden;
}

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

.badge {
    position: absolute;
    top: 12px;
    right: 12px;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.badge.bestseller {
    background-color: var(--color-amazon);
    color: var(--color-dark);
}

.book-info {
    padding: 24px;
}

.book-info h3 {
    margin-bottom: 12px;
    color: var(--color-dark);
}

.book-description {
    color: var(--color-text-light);
    font-size: 0.95rem;
    margin-bottom: 16px;
    line-height: 1.6;
}

.book-meta {
    margin-bottom: 20px;
}

.rating {
    color: var(--color-amazon);
    font-weight: 500;
}

.rating small {
    color: var(--color-text-light);
    font-weight: 400;
}

.pages {
    color: var(--color-text-light);
    font-size: 0.9rem;
}

.language {
    display: inline-block;
    background-color: var(--color-cream);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.85rem;
    margin-right: 8px;
    margin-bottom: 8px;
}

.book-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.book-buttons .btn {
    font-size: 0.9rem;
    padding: 12px 20px;
}

.btn-amazon-us {
    background-color: #146eb4;
}

.btn-amazon-us:hover {
    background-color: #0f5a94;
}

.amazon-icon {
    flex-shrink: 0;
}

/* About Section */
.about {
    padding: 100px 0;
    background-color: var(--color-cream);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 80px;
    align-items: center;
}

.about-image img {
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
}

.about-text h2 {
    margin-bottom: 24px;
    color: var(--color-dark);
}

.about-text .lead {
    font-size: 1.25rem;
    color: var(--color-text);
    margin-bottom: 20px;
    font-weight: 500;
}

.about-text p {
    margin-bottom: 16px;
    color: var(--color-text-light);
}

.about-stats {
    display: flex;
    gap: 40px;
    margin-top: 40px;
    padding-top: 40px;
    border-top: 1px solid rgba(0,0,0,0.1);
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-dark);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* CTA Section */
.cta {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    text-align: center;
}

.cta h2 {
    color: var(--color-dark);
    margin-bottom: 16px;
}

.cta p {
    font-size: 1.125rem;
    color: var(--color-dark);
    opacity: 0.8;
    margin-bottom: 32px;
}

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

.cta .btn-primary:hover {
    background-color: #000;
}

/* Footer */
.footer {
    background-color: var(--color-dark);
    color: var(--color-white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-logo {
    height: 40px;
    margin-bottom: 16px;
}

.footer-brand p {
    color: rgba(255,255,255,0.7);
    max-width: 300px;
}

.footer h4 {
    font-size: 1rem;
    margin-bottom: 20px;
    color: var(--color-primary);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: rgba(255,255,255,0.7);
    transition: var(--transition);
}

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

.footer-social p {
    color: rgba(255,255,255,0.7);
    margin-bottom: 16px;
}

.social-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: rgba(255,255,255,0.1);
    color: var(--color-white);
    transition: var(--transition);
    font-size: 1.25rem;
}

.social-link:hover {
    background-color: var(--color-primary);
    color: var(--color-dark);
    transform: translateY(-3px);
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
    text-align: center;
}

.footer-bottom p {
    color: rgba(255,255,255,0.5);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 992px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-image {
        order: -1;
        max-width: 400px;
        margin: 0 auto;
    }

    .books-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .about-image {
        max-width: 350px;
        margin: 0 auto;
    }

    .about-stats {
        justify-content: center;
    }

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

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-white);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        box-shadow: var(--shadow-md);
    }

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

    .nav-links li {
        padding: 15px 0;
        border-bottom: 1px solid rgba(0,0,0,0.1);
    }

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

    .books-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
    }

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

    .footer-brand {
        margin: 0 auto;
    }

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

@media (max-width: 480px) {
    .hero {
        padding: 120px 0 60px;
    }

    .about-stats {
        flex-direction: column;
        gap: 24px;
    }

    .btn {
        width: 100%;
    }
}