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

:root {
    --primary-color: #F9CB55;
    --primary-dark: #F9CB55;
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --bg-dark: #000000;
    --border-color: #D2D2D7;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
    position: relative;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 400;
    font-size: 14px;
    transition: var(--transition);
}

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

.btn-nav {
    background: var(--primary-color);
    color: white !important;
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 500;
}

.btn-nav:hover {
    background: var(--primary-dark);
    color: white !important;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}


/* Hero Section */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(180deg, #FFFFFF 0%, #F5F5F7 100%);
    min-height: 90vh;
    display: flex;
    align-items: center;
}

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

.hero-title {
    font-size: 56px;
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -1.5px;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: 21px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.5;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

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

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

.hero .btn-primary {
    color: black;
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

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

.hero-image {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
}

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

/* Stats Section */
.stats {
    padding: 0px 0;
    background: var(--bg-primary);
}

.stats .container {
    display: flex;
    flex-direction: column;
    min-height: 100%;
}

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

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

.stats-footer-note {
    text-align: center;
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: auto;
    margin-left: auto;
    font-style: italic;
    opacity: 0.8;
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -1px;
}

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

/* Features Section */
.features {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -1px;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 28px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.section-description {
    font-size: 19px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-card {
    background: var(--bg-primary);
    padding: 40px;
    border-radius: 20px;
    transition: var(--transition);
    border: 1px solid transparent;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-color);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
    display: block;
}

.feature-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-description {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Reading Modes Section */
.reading-modes {
    padding: 100px 0;
    background: var(--bg-primary);
}

.reading-image-container {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 60px auto;
    max-width: 500px;
    width: 100%;
    padding: 0 24px;
}

.reading-image-container img {
    width: 100%;
    max-width: 500px;
    height: auto;
    display: block;
    margin: 0 auto;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
}

.reading-features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-top: 60px;
}

.reading-feature-card {
    background: var(--bg-secondary);
    padding: 40px;
    border-radius: 20px;
    transition: var(--transition);
    border: 1px solid transparent;
}

.reading-feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-color);
}

.reading-feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
    display: block;
}

.reading-feature-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.reading-feature-description {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Library Section */
.library {
    padding: 100px 0;
    background: var(--bg-secondary);
}

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

.library-features {
    margin-top: 32px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.library-feature {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 16px;
    color: var(--text-primary);
}

.check-icon {
    width: 24px;
    height: 24px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 14px;
    flex-shrink: 0;
}

.library-mockup {
    background: var(--bg-primary);
    border-radius: 24px;
    padding: 32px;
    box-shadow: var(--shadow-lg);
}

.mockup-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.mockup-item {
    aspect-ratio: 2/3;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    opacity: 0.8;
}

.mockup-item:nth-child(2) {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.mockup-item:nth-child(3) {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.mockup-item:nth-child(4) {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.mockup-item:nth-child(5) {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}

.mockup-item:nth-child(6) {
    background: linear-gradient(135deg, #30cfd0 0%, #330867 100%);
}

/* Sync Section */
.sync {
    padding: 100px 0;
    background: var(--bg-primary);
}

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

.sync-card {
    text-align: center;
    padding: 40px 32px;
}

.sync-icon {
    font-size: 56px;
    margin-bottom: 24px;
    display: block;
}

.sync-title {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.sync-description {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Testimonials Section */
.testimonials {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.testimonial-card {
    background: var(--bg-primary);
    padding: 32px;
    border-radius: 20px;
    box-shadow: var(--shadow);
}

.testimonial-rating {
    color: #FFD700;
    font-size: 20px;
    margin-bottom: 16px;
    letter-spacing: 2px;
}

.testimonial-text {
    font-size: 16px;
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 20px;
    font-style: italic;
}

.testimonial-author {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
}

/* FAQ Section */
.faq {
    padding: 100px 0;
    background: var(--bg-primary);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid var(--border-color);
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 0;
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    font-size: 18px;
    font-weight: 500;
    color: var(--text-primary);
    transition: var(--transition);
}

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

.faq-icon {
    font-size: 24px;
    font-weight: 300;
    color: var(--text-secondary);
    transition: var(--transition);
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
    color: var(--primary-color);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding-bottom: 24px;
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 16px;
}

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

.cta-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -1px;
}

.cta-subtitle {
    font-size: 21px;
    margin-bottom: 40px;
    opacity: 0.9;
}

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

.cta .btn-primary:hover {
    background: rgba(0, 0, 0, 0.8);
    transform: translateY(-2px);
}

/* Footer */
.footer {
    padding: 60px 0 32px;
    background: var(--bg-dark);
    color: white;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-brand .logo {
    color: white;
    margin-bottom: 12px;
}

.footer-description {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
}

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

.footer-title {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
    color: white;
}

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

.footer-column ul li {
    margin-bottom: 12px;
}

.footer-column a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 32px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
}

.footer-social {
    display: flex;
    gap: 24px;
}

.footer-social a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

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

/* Responsive Design */
@media (max-width: 1024px) {
    .hero-content,
    .library-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .hero-image {
        order: -1;
    }

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

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

@media (max-width: 768px) {
    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: saturate(180%) blur(20px);
        flex-direction: column;
        padding: 24px;
        border-top: 1px solid var(--border-color);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
        gap: 16px;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-links li {
        width: 100%;
    }

    .nav-links a {
        display: block;
        padding: 12px 0;
        width: 100%;
    }

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

    .hero {
        padding: 120px 0 60px;
    }

    .hero-title {
        font-size: 40px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .section-title {
        font-size: 36px;
    }

    .section-subtitle {
        font-size: 24px;
    }

    .features-grid,
    .reading-features-grid,
    .sync-grid,
    .testimonials-grid {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 32px;
    }

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

    .footer-links {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }

    .cta-title {
        font-size: 36px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 32px;
    }

    .hero-buttons {
        flex-direction: column;
    }

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

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

    .stat-number {
        font-size: 36px;
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card,
.mode-card,
.testimonial-card {
    animation: fadeInUp 0.6s ease-out;
}