/* Performance optimizations and modern CSS */
:root {
    --primary-color: #0071e3;
    --secondary-color: #147ce5;
    --background-color: #ffffff;
    --text-color: #1d1d1f;
    --light-gray: #f5f5f7;
    --spacing-unit: 1rem;
    --border-radius: 12px;
    --transition: all 0.3s ease;
    --shadow-light: 0 4px 12px rgba(0, 0, 0, 0.05);
    --shadow-medium: 0 8px 24px rgba(0, 0, 0, 0.1);
    --shadow-heavy: 0 20px 40px rgba(0, 0, 0, 0.1);
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, sans-serif;
    line-height: 1.5;
    color: var(--text-color);
    background-color: var(--background-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container and layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-unit);
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    padding: 1rem 0;
    transition: var(--transition);
}

nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color);
    text-decoration: none;
    transition: var(--transition);
}

.logo:hover {
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 6rem 0;
    background: linear-gradient(180deg, var(--light-gray) 0%, var(--background-color) 100%);
    position: relative;
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 2rem;
    width: 100%;
}

.hero-book {
    position: relative;
    max-width: 300px;
    margin: 0 auto;
}

.hero-book-cover {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-heavy);
    transform: perspective(1000px) rotateY(-5deg);
    transition: var(--transition);
    will-change: transform;
}

.hero-book-cover:hover {
    transform: perspective(1000px) rotateY(0deg) scale(1.02);
}

.book-badge {
    position: absolute;
    top: -1rem;
    right: -1rem;
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(0, 113, 227, 0.3);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.hero-text {
    max-width: 600px;
    margin: 0 auto;
}

.hero-text h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
    background: linear-gradient(135deg, var(--text-color) 0%, var(--primary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.author {
    font-size: 1.25rem;
    color: #666;
    margin-bottom: 1rem;
}

.subtitle {
    font-size: 1.125rem;
    color: #666;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.subtitle em {
    color: var(--primary-color);
    font-style: normal;
    font-weight: 600;
}

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

/* Buttons and CTAs */
.cta-button {
    background: var(--primary-color);
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-block;
    box-shadow: var(--shadow-light);
}

.cta-button:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.cta-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    padding: 0.75rem 1.5rem;
    border: 2px solid transparent;
    border-radius: 25px;
}

.cta-link:hover {
    color: var(--secondary-color);
    border-color: var(--secondary-color);
}

/* Benefits Section */
.benefits {
    padding: 6rem 0;
    background: var(--light-gray);
}

.benefits h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 3rem;
    color: var(--text-color);
}

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

.benefit-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border: 1px solid transparent;
}

.benefit-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
    border-color: var(--primary-color);
}

.benefit-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.benefit-card p {
    color: #666;
    line-height: 1.6;
}

/* Author Section */
.author-section {
    padding: 6rem 0;
}

.author-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 3rem;
    align-items: center;
}

.author-image {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-medium);
    transition: var(--transition);
}

.author-image:hover {
    transform: scale(1.02);
}

.author-info h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.author-info p {
    margin-bottom: 1rem;
    line-height: 1.6;
    color: #666;
}

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

.author-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 1rem;
    border: 1px solid var(--primary-color);
    border-radius: 20px;
}

.author-link:hover {
    color: white;
    background: var(--primary-color);
}

/* Purchase Section */
.purchase {
    padding: 6rem 0;
    background: var(--light-gray);
    text-align: center;
}

.purchase h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.purchase-options {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.purchase-button {
    background: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    border-radius: 25px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    box-shadow: var(--shadow-light);
}

.purchase-button:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.publisher-note {
    color: #666;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

.publisher-note a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.publisher-note a:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    padding: 2rem 0;
    text-align: center;
    background: var(--light-gray);
    color: #666;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-content {
        padding: 2rem 0;
    }

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

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

    .author-image {
        max-width: 300px;
        margin: 0 auto;
    }

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

    .purchase-options {
        flex-direction: column;
        align-items: center;
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
}

@media (max-width: 480px) {
    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }

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

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

    .benefit-card {
        padding: 1.5rem;
    }

    .author-links {
        flex-direction: column;
        align-items: center;
    }
}

/* Print styles */
@media print {
    nav {
        position: static;
        background: white;
    }

    .hero {
        min-height: auto;
        padding: 2rem 0;
    }

    .cta-button,
    .purchase-button {
        border: 1px solid black;
        color: black;
        background: white;
    }
}