/* ========================================
   MODERN EBOOK LANDING PAGE STYLES
   ======================================== */

/* CSS Variables */
:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #ec4899;
    --accent: #f59e0b;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-heading: 'Playfair Display', Georgia, serif;
    
    /* Spacing */
    --container-width: 1200px;
    --section-padding: 100px;
    --grid-gap: 30px;
    
    /* Animations */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

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

/* ========================================
   NAVIGATION
   ======================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-md);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    transition: color var(--transition-fast);
}

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

.logo strong {
    color: var(--primary);
    font-weight: 800;
}

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

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

.nav-link {
    position: relative;
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width var(--transition-base);
}

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

.nav-link.active::after,
.nav-link:hover::after {
    width: 100%;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 24px;
    height: 24px;
}

.mobile-toggle span {
    width: 100%;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

/* ========================================
   BUTTONS
   ======================================== */

.btn-primary,
.btn-secondary,
.btn-large {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 12px;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn-primary:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

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

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

.full-width {
    width: 100%;
    justify-content: center;
}

/* ========================================
   HERO SECTION
   ======================================== */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    overflow: hidden;
}

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

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.6;
    animation: float 8s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    top: -100px;
    left: -100px;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    top: 50%;
    right: -50px;
    animation-delay: -2s;
}

.orb-3 {
    width: 600px;
    height: 600px;
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    bottom: -200px;
    left: 50%;
    animation-delay: -4s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.9); }
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
    padding: 60px 0;
}

.hero-content {
    z-index: 1;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: 50px;
    color: var(--primary);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 24px;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--primary);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.2); }
}

.hero-title {
    font-family: var(--font-heading);
    font-size: 64px;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
}

.hero-description {
    font-size: 18px;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 32px;
    max-width: 540px;
}

.hero-stats {
    display: flex;
    gap: 24px;
    margin-bottom: 40px;
    padding: 24px 0;
}

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

.stat-number {
    font-size: 32px;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 500;
}

.stat-divider {
    width: 1px;
    background: var(--border-color);
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

/* Hero Visual */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.book-3d {
    position: relative;
    width: 100%;
    max-width: 500px;
    aspect-ratio: 1;
}

.book-cover {
    position: relative;
    width: 320px;
    height: 450px;
    margin: 0 auto;
    transform-style: preserve-3d;
    animation: bookFloat 6s ease-in-out infinite;
}

@keyframes bookFloat {
    0%, 100% { transform: translateY(0) rotateY(-15deg); }
    50% { transform: translateY(-20px) rotateY(-20deg); }
}

.book-spine {
    position: absolute;
    left: 0;
    top: 0;
    width: 40px;
    height: 100%;
    background: linear-gradient(90deg, #2d3748 0%, #4a5568 100%);
    transform: rotateY(-90deg);
    transform-origin: left;
}

.book-front {
    position: relative;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 4px;
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

.book-front::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 0, 0, 0.1) 0%, transparent 50%);
}

.book-content {
    position: relative;
    padding: 60px 40px;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    color: white;
}

.book-content h3 {
    font-family: var(--font-heading);
    font-size: 48px;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 16px;
}

.book-badge {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(245, 158, 11, 0.9);
    border-radius: 20px;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 1px;
    margin-bottom: 24px;
    text-transform: uppercase;
}

.book-decorative-line {
    width: 60px;
    height: 3px;
    background: rgba(255, 255, 255, 0.6);
    margin: 24px 0;
}

.book-subtitle {
    font-size: 13px;
    font-weight: 400;
    opacity: 0.7;
    letter-spacing: 0.5px;
    margin-top: 8px;
}

.book-content p {
    font-size: 18px;
    font-weight: 300;
    opacity: 0.9;
}

.book-author {
    font-size: 16px;
    font-weight: 600;
    opacity: 0.8;
}

.floating-elements {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
}

.float-icon {
    position: absolute;
    font-size: 40px;
    animation: iconFloat 4s ease-in-out infinite;
}

.icon-1 {
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.icon-2 {
    top: 20%;
    right: 5%;
    animation-delay: -1s;
}

.icon-3 {
    bottom: 20%;
    left: 5%;
    animation-delay: -2s;
}

.icon-4 {
    bottom: 15%;
    right: 10%;
    animation-delay: -3s;
}

@keyframes iconFloat {
    0%, 100% { transform: translateY(0) rotate(0deg); opacity: 0.6; }
    50% { transform: translateY(-30px) rotate(10deg); opacity: 1; }
}

/* ========================================
   SECTIONS
   ======================================== */

.section {
    padding: var(--section-padding) 0;
    position: relative;
}

.section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, transparent, var(--border-color), transparent);
    opacity: 0.5;
}

.section-header {
    margin-bottom: 60px;
}

.section-header.center {
    text-align: center;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.section-label {
    display: inline-block;
    padding: 6px 16px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(236, 72, 153, 0.1) 100%);
    border-radius: 50px;
    color: var(--primary);
    font-size: 14px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 16px;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.section-description {
    font-size: 18px;
    line-height: 1.7;
    color: var(--text-secondary);
}

/* ========================================
   FEATURES GRID
   ======================================== */

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--grid-gap);
}

@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
}

.feature-card {
    padding: 40px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    transition: all var(--transition-base);
    position: relative;
}

.feature-card::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 20px;
    padding: 1px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: exclude;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    background: white;
}

.feature-card:hover::after {
    opacity: 1;
}

.feature-icon {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border-radius: 16px;
    color: white;
    margin-bottom: 24px;
    transition: transform var(--transition-base);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1) rotate(5deg);
}

.feature-card h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   PREVIEW SECTION
   ======================================== */

.preview-section {
    background: var(--bg-secondary);
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--grid-gap);
}

.chapter-card {
    padding: 40px;
    background: white;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.chapter-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 0;
    background: linear-gradient(180deg, var(--primary) 0%, var(--secondary) 100%);
    transition: height var(--transition-slow);
}

.chapter-card:hover::before {
    height: 100%;
}

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

.chapter-number {
    font-family: var(--font-heading);
    font-size: 64px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: 16px;
    opacity: 0.2;
}

.chapter-card h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.chapter-card > p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.7;
}

.chapter-topics {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.chapter-topics li {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    font-size: 14px;
}

.chapter-topics li::before {
    content: '→';
    color: var(--primary);
    font-weight: 700;
}

/* ========================================
   AUTHOR SECTION
   ======================================== */

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

.author-image {
    position: relative;
}

.author-photo-wrapper {
    position: relative;
    width: 100%;
    max-width: 400px;
}

.author-photo {
    width: 100%;
    aspect-ratio: 3/4;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 20px;
    position: relative;
    overflow: hidden;
}

.author-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.author-decoration {
    position: absolute;
    top: 20px;
    right: -20px;
    width: 100%;
    height: 100%;
    border: 3px solid var(--primary);
    border-radius: 20px;
    z-index: -1;
}

.author-content {
    max-width: 600px;
}

.author-title {
    font-size: 18px;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 24px;
}

.author-bio {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 32px;
}

.author-bio p {
    color: var(--text-secondary);
    line-height: 1.8;
}

.author-credentials {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 32px;
    padding: 24px;
    background: var(--bg-secondary);
    border-radius: 12px;
}

.credential-item {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-primary);
    font-weight: 500;
}

.credential-item svg {
    color: var(--accent);
    flex-shrink: 0;
}

.author-social {
    display: flex;
    gap: 16px;
}

.social-link {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-secondary);
    transition: all var(--transition-base);
}

.social-link:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
    transform: translateY(-4px);
}

/* ========================================
   TESTIMONIALS
   ======================================== */

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--grid-gap);
}

.testimonial-card {
    padding: 32px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    gap: 20px;
    position: relative;
}

.testimonial-card::before {
    content: '"';
    position: absolute;
    top: -10px;
    left: 20px;
    font-size: 80px;
    font-family: var(--font-heading);
    color: var(--bg-tertiary);
    line-height: 1;
    z-index: 0;
}

.testimonial-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.testimonial-card.featured {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    border: none;
}

.testimonial-rating {
    display: flex;
    gap: 4px;
}

.star {
    color: var(--accent);
    font-size: 20px;
}

.testimonial-card.featured .star {
    color: rgba(255, 255, 255, 0.9);
}

.testimonial-text {
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-secondary);
    flex-grow: 1;
}

.testimonial-card.featured .testimonial-text {
    color: rgba(255, 255, 255, 0.95);
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 16px;
}

.author-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    flex-shrink: 0;
    overflow: hidden;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.author-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.author-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.testimonial-card.featured .author-name {
    color: white;
}

.author-role {
    font-size: 14px;
    color: var(--text-muted);
}

.testimonial-card.featured .author-role {
    color: rgba(255, 255, 255, 0.8);
}

/* ========================================
   DOWNLOAD SECTION
   ======================================== */

.download-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.download-card {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 60px;
    align-items: center;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 30px;
    padding: 60px;
}

.download-content h2 {
    font-family: var(--font-heading);
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 16px;
}

.download-content > p {
    font-size: 18px;
    line-height: 1.7;
    margin-bottom: 32px;
    opacity: 0.9;
}

.download-form {
    margin-bottom: 32px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}

.form-input {
    padding: 16px 20px;
    background: rgba(255, 255, 255, 0.95);
    border: 2px solid transparent;
    border-radius: 12px;
    font-size: 15px;
    font-family: var(--font-body);
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    background: white;
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.form-input::placeholder {
    color: var(--text-muted);
}

.form-note {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    opacity: 0.8;
    margin-top: 12px;
}

.form-note svg {
    flex-shrink: 0;
}

.download-features {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 15px;
}

.feature-item svg {
    flex-shrink: 0;
}

.download-visual {
    position: relative;
    height: 400px;
}

.download-devices {
    position: relative;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.device-stack {
    position: relative;
    width: 100%;
    height: 100%;
}

.device {
    position: absolute;
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.device.laptop {
    width: 280px;
    height: 180px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.device.laptop::before {
    content: '';
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    bottom: 10px;
    background: var(--text-primary);
    border-radius: 4px;
}

.device.tablet {
    width: 180px;
    height: 240px;
    top: 50%;
    right: 0;
    transform: translateY(-50%) rotate(5deg);
    background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);
}

.device.phone {
    width: 120px;
    height: 240px;
    bottom: 10%;
    left: 10%;
    transform: rotate(-10deg);
    background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
}

/* ========================================
   FOOTER
   ======================================== */

.footer {
    background: var(--text-primary);
    color: white;
    padding: 80px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 60px;
    margin-bottom: 60px;
}

.footer-brand .logo {
    color: white;
    margin-bottom: 16px;
}

.footer-tagline {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
    max-width: 300px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
}

.footer-column h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    color: white;
}

.footer-column a {
    display: block;
    color: rgba(255, 255, 255, 0.7);
    font-size: 15px;
    margin-bottom: 10px;
    transition: color var(--transition-fast);
}

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

.footer-social {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

@media (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }
    
    .hero-title {
        font-size: 52px;
    }
    
    .section-title {
        font-size: 40px;
    }
    
    .hero-grid,
    .author-grid {
        grid-template-columns: 1fr;
        gap: 60px;
    }
    
    .download-card {
        grid-template-columns: 1fr;
    }
    
    .download-visual {
        height: 300px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
        --grid-gap: 20px;
    }
    
    .nav-menu {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        gap: 20px;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .mobile-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .mobile-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .mobile-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    .hero-title {
        font-size: 40px;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 16px;
    }
    
    .stat-divider {
        display: none;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .btn-large,
    .btn-primary,
    .btn-secondary {
        width: 100%;
        justify-content: center;
    }
    
    .preview-grid,
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .download-card {
        padding: 40px 30px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 32px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .book-cover {
        width: 240px;
        height: 340px;
    }
    
    .book-content h3 {
        font-size: 36px;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   UTILITIES
   ======================================== */

.spinner {
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.btn-loading,
.btn-text,
.btn-icon {
    position: relative;
    z-index: 1;
}

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

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }

/* Scroll animations */
@media (prefers-reduced-motion: no-preference) {
    .fade-in {
        opacity: 0;
        transform: translateY(30px);
        transition: opacity 0.6s ease, transform 0.6s ease;
    }
    
    .fade-in.visible {
        opacity: 1;
        transform: translateY(0);
    }
}