/* ReadingKulture - Premium Landing Page Styles */

:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #10b981;
    --accent: #f59e0b;
    --dark: #0f172a;
    --dark-lighter: #1e293b;
    --gray-900: #111827;
    --gray-800: #1f2937;
    --gray-700: #374151;
    --gray-600: #4b5563;
    --gray-500: #6b7280;
    --gray-400: #9ca3af;
    --gray-300: #d1d5db;
    --gray-200: #e5e7eb;
    --gray-100: #f3f4f6;
    --white: #ffffff;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
    --gradient-dark: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
    --gradient-glow: radial-gradient(ellipse at center, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    /* Spacing */
    --container-width: 1200px;
    --section-padding: 100px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 32px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 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);
    --shadow-glow: 0 0 60px rgba(99, 102, 241, 0.3);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-300);
    background: var(--dark);
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--white);
    font-weight: 700;
    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); }

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.section-header p {
    margin-top: 16px;
    font-size: 1.125rem;
    color: var(--gray-400);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 16px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white);
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 80px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--gray-600);
}

.btn-secondary:hover {
    background: var(--gray-800);
    border-color: var(--gray-500);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--white);
}

.logo-image {
    height: 40px;
    width: auto;
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--gray-400);
    font-weight: 500;
    transition: color 0.2s ease;
}

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

.nav-cta {
    padding: 10px 20px;
    background: var(--primary);
    color: var(--white);
    border-radius: var(--radius-sm);
    font-weight: 600;
    transition: background 0.2s ease;
}

.nav-cta:hover {
    background: var(--primary-dark);
}

.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: 24px;
    height: 2px;
    background: var(--white);
    border-radius: 2px;
    transition: all 0.3s ease;
}

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

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

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

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
    z-index: 999;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.6);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: var(--gradient-glow);
    opacity: 0.5;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-block;
    padding: 8px 16px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: 50px;
    color: var(--primary-light);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray-400);
    margin: 24px 0 32px;
    max-width: 500px;
}

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

.hero-stats {
    display: flex;
    gap: 40px;
    margin-top: 48px;
    padding-top: 48px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--white);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray-500);
}

/* Phone Mockup */
.hero-image {
    display: flex;
    justify-content: center;
}

.phone-mockup {
    width: 280px;
    height: 560px;
    background: var(--gray-900);
    border-radius: 40px;
    padding: 12px;
    box-shadow: var(--shadow-xl), var(--shadow-glow);
    border: 2px solid var(--gray-700);
    transform: perspective(1000px) rotateY(-5deg);
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: perspective(1000px) rotateY(-5deg) translateY(0); }
    50% { transform: perspective(1000px) rotateY(-5deg) translateY(-20px); }
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--dark);
    border-radius: 32px;
    overflow: hidden;
}

.app-preview {
    height: 100%;
    padding: 20px;
}

.preview-header {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 20px;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.preview-book {
    aspect-ratio: 2/3;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 8px;
    opacity: 0.8;
}

.preview-book:nth-child(2) { background: linear-gradient(135deg, #10b981 0%, #059669 100%); }
.preview-book:nth-child(3) { background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%); }
.preview-book:nth-child(4) { background: linear-gradient(135deg, #ec4899 0%, #db2777 100%); }
.preview-book:nth-child(5) { background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%); }
.preview-book:nth-child(6) { background: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%); }

/* Features Section */
.features {
    padding: 60px 0 var(--section-padding) 0;
    background: var(--gradient-dark);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all 0.3s ease;
}

.feature-card:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(99, 102, 241, 0.3);
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.feature-card h3 {
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--gray-400);
    font-size: 0.95rem;
}

/* How It Works */
.how-it-works {
    padding: var(--section-padding) 0;
}

.steps {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 24px;
}

.step {
    text-align: center;
    padding: 40px;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    flex: 1;
    max-width: 300px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--white);
    margin: 0 auto 20px;
}

.step h3 {
    margin-bottom: 12px;
}

.step p {
    color: var(--gray-400);
}

.step-arrow {
    font-size: 2rem;
    color: var(--gray-600);
}

/* Testimonials */
.testimonials {
    padding: var(--section-padding) 0;
    background: var(--gradient-dark);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.testimonial-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: 32px;
}

.testimonial-stars {
    margin-bottom: 16px;
}

.testimonial-card > p {
    font-size: 1.1rem;
    color: var(--gray-300);
    margin-bottom: 24px;
    font-style: italic;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 12px;
}

.author-avatar {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: var(--white);
}

.testimonial-author strong {
    display: block;
    color: var(--white);
}

.testimonial-author span {
    font-size: 0.875rem;
    color: var(--gray-500);
}

/* Download Section */
.download {
    padding: var(--section-padding) 0;
    text-align: center;
}

.download-content {
    max-width: 600px;
    margin: 0 auto;
}

.download-content h2 {
    margin-bottom: 16px;
}

.download-content > p {
    color: var(--gray-400);
    font-size: 1.125rem;
    margin-bottom: 40px;
}

.download-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.store-button {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 24px;
    background: var(--gray-800);
    border: 1px solid var(--gray-700);
    border-radius: var(--radius-md);
    color: var(--white);
    transition: all 0.3s ease;
}

.store-button:hover {
    background: var(--gray-700);
    transform: translateY(-2px);
}

.store-button.coming-soon {
    opacity: 0.6;
    cursor: not-allowed;
}

.store-button div {
    text-align: left;
}

.store-button span {
    display: block;
    font-size: 0.75rem;
    color: var(--gray-400);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.store-button strong {
    font-size: 1.125rem;
}

.download-note {
    margin-top: 24px;
    color: var(--gray-500);
}

/* FAQ Preview */
.faq-preview {
    padding: 60px 0 var(--section-padding) 0;
    background: var(--gradient-dark);
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-bottom: 40px;
}

.faq-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    padding: 24px;
}

.faq-item h3 {
    margin-bottom: 12px;
    font-size: 1.1rem;
}

.faq-item p {
    color: var(--gray-400);
}

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

/* Footer */
.footer {
    padding: 60px 0 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

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

.footer-brand p {
    margin: 16px 0;
    color: var(--gray-500);
}

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

.social-links a {
    width: 40px;
    height: 40px;
    background: var(--gray-800);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--gray-400);
    transition: all 0.2s ease;
}

.social-links a:hover {
    background: var(--primary);
    color: var(--white);
}

.footer-links h4 {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--gray-400);
    margin-bottom: 16px;
}

.footer-links a {
    display: block;
    color: var(--gray-500);
    margin-bottom: 12px;
    transition: color 0.2s ease;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--gray-600);
    font-size: 0.875rem;
}

.footer-bottom a {
    color: var(--primary-light);
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    position: relative;
}

.footer-bottom a:hover {
    color: var(--primary);
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content {
        order: 1;
    }
    
    .hero-image {
        order: 0;
    }
    
    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .phone-mockup {
        width: 220px;
        height: 440px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }
    
    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(15, 23, 42, 0.98);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-10px);
        transition: all 0.3s ease;
    }
    
    .nav-links.active {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }
    
    .nav-links a {
        padding: 15px 10px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .nav-links a:last-child {
        border-bottom: none;
    }
    
    .nav-cta {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .steps {
        flex-direction: column;
    }
    
    .step {
        max-width: 100%;
    }
    
    .step-arrow {
        transform: rotate(90deg);
    }
    
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .faq-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .download-buttons {
        flex-direction: column;
    }
    
    .store-button {
        width: 100%;
        justify-content: center;
    }
}