/* ============================================
   PhotoHunt AI - Liquid Glass Design System
   ============================================ */

/* CSS Custom Properties (Design Tokens) */
:root {
    /* Colors */
    --color-primary: #667eea;
    --color-secondary: #764ba2;
    --color-accent-cyan: #00f2fe;
    --color-accent-magenta: #f093fb;
    --color-text-primary: #ffffff;
    --color-text-secondary: rgba(255, 255, 255, 0.8);
    --color-text-muted: rgba(255, 255, 255, 0.6);
    
    /* Glass Effect */
    --glass-bg: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.18);
    --glass-shadow: rgba(0, 0, 0, 0.1);
    --glass-blur: 20px;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Border Radius (Only 2 values as per Liquid Glass philosophy) */
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3rem;
    --font-size-6xl: 4rem;
    
    /* Transitions (Physics-based easing) */
    --transition-smooth: cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
    --transition-elastic: cubic-bezier(0.175, 0.885, 0.32, 1.275);
    
    /* Z-index layers */
    --z-base: 1;
    --z-elevated: 10;
    --z-navigation: 100;
    --z-modal: 1000;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--color-text-primary);
    background: linear-gradient(135deg, #1e1b4b 0%, #0f172a 50%, #1e293b 100%);
    background-attachment: fixed;
    line-height: 1.6;
    overflow-x: hidden;
}

/* Container */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ============================================
   Glass Card Component (Core Building Block)
   ============================================ */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur)) saturate(180%);
    -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-2xl);
    box-shadow: 0 8px 32px var(--glass-shadow);
    transition: all 0.3s var(--transition-smooth);
}

.glass-card:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.25);
    box-shadow: 0 12px 48px rgba(0, 0, 0, 0.15), 
                0 0 0 1px rgba(255, 255, 255, 0.1) inset;
    transform: translateY(-2px);
}

/* ============================================
   Navigation
   ============================================ */
.nav-glass {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-navigation);
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(var(--glass-blur)) saturate(180%);
    -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
    border-bottom: 1px solid var(--glass-border);
    padding: var(--spacing-sm) 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-size-xl);
    font-weight: 700;
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--color-accent-cyan);
}

.logo-text {
    background: linear-gradient(135deg, var(--color-accent-cyan), var(--color-accent-magenta));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: color 0.3s var(--transition-smooth);
}

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

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--color-text-primary);
    cursor: pointer;
    padding: var(--spacing-xs);
}

/* ============================================
   Buttons (Glass Style)
   ============================================ */
.glass-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    color: var(--color-text-primary);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: all 0.3s var(--transition-smooth);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.glass-button:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    box-shadow: 0 0 20px rgba(0, 242, 254, 0.3) inset,
                0 8px 24px rgba(0, 0, 0, 0.15);
    transform: translateY(-2px);
}

.glass-button-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.glass-button-primary:hover {
    background: linear-gradient(135deg, #7c8ff5, #8b5cb8);
    box-shadow: 0 0 30px rgba(102, 126, 234, 0.5) inset,
                0 12px 32px rgba(102, 126, 234, 0.3);
}

.glass-button-secondary {
    background: rgba(255, 255, 255, 0.05);
}

.glass-button-large {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-base);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: var(--spacing-3xl);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(240, 147, 251, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(0, 242, 254, 0.1) 0%, transparent 40%);
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: var(--z-base);
    text-align: center;
    padding: var(--spacing-2xl) 0;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.hero-badge i {
    width: 16px;
    height: 16px;
    color: var(--color-accent-cyan);
}

.hero-title {
    font-size: clamp(var(--font-size-4xl), 8vw, var(--font-size-6xl));
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
    letter-spacing: -0.02em;
}

.gradient-text {
    background: linear-gradient(135deg, var(--color-accent-cyan), var(--color-accent-magenta));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    max-width: 700px;
    margin: 0 auto var(--spacing-xl);
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--spacing-3xl);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-lg);
    max-width: 600px;
    margin: 0 auto;
}

.stat-item {
    padding: var(--spacing-lg);
    text-align: center;
}

.stat-value {
    font-size: var(--font-size-3xl);
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-accent-cyan), var(--color-accent-magenta));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    color: var(--color-text-muted);
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(10px); }
}

/* Fade-in animations */
.animate-fade-in {
    animation: fadeIn 0.8s var(--transition-smooth) forwards;
    opacity: 0;
}

.animate-fade-in-delay-1 {
    animation: fadeIn 0.8s var(--transition-smooth) 0.2s forwards;
    opacity: 0;
}

.animate-fade-in-delay-2 {
    animation: fadeIn 0.8s var(--transition-smooth) 0.4s forwards;
    opacity: 0;
}

.animate-fade-in-delay-3 {
    animation: fadeIn 0.8s var(--transition-smooth) 0.6s forwards;
    opacity: 0;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   Section Styles
   ============================================ */
section {
    padding: var(--spacing-3xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-title {
    font-size: clamp(var(--font-size-3xl), 5vw, var(--font-size-5xl));
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   Features Section
   ============================================ */
.features {
    background: linear-gradient(180deg, transparent 0%, rgba(15, 23, 42, 0.5) 100%);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    padding: var(--spacing-xl);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.feature-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border-radius: var(--radius-2xl);
    color: white;
    margin-bottom: var(--spacing-sm);
}

.feature-icon i {
    width: 32px;
    height: 32px;
}

.feature-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.feature-description {
    color: var(--color-text-secondary);
    line-height: 1.8;
    flex-grow: 1;
}

.feature-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.tag {
    padding: var(--spacing-xs) var(--spacing-sm);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

/* ============================================
   How It Works (Timeline)
   ============================================ */
.timeline {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.timeline-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.timeline-number {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-2xl);
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.timeline-content {
    padding: var(--spacing-xl);
}

.timeline-content i {
    width: 32px;
    height: 32px;
    color: var(--color-accent-cyan);
    margin-bottom: var(--spacing-md);
}

.timeline-content h3 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

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

/* ============================================
   Gallery Section
   ============================================ */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.gallery-item {
    position: relative;
    aspect-ratio: 1;
    overflow: hidden;
    cursor: pointer;
}

.gallery-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s var(--transition-smooth);
}

.gallery-item:hover .gallery-image {
    transform: scale(1.1);
}

.gallery-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, transparent 0%, rgba(0, 0, 0, 0.8) 100%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: var(--spacing-lg);
    opacity: 0;
    transition: opacity 0.3s var(--transition-smooth);
}

.gallery-item:hover .gallery-overlay {
    opacity: 1;
}

.gallery-info h4 {
    font-size: var(--font-size-lg);
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.gallery-info p {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.gallery-info i {
    width: 14px;
    height: 14px;
}

.gallery-stats {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.gallery-stats span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.gallery-stats i {
    width: 16px;
    height: 16px;
}

/* ============================================
   CTA Section
   ============================================ */
.cta {
    background: linear-gradient(180deg, rgba(15, 23, 42, 0.5) 0%, transparent 100%);
}

.cta-content {
    padding: var(--spacing-3xl);
    text-align: center;
}

.cta-title {
    font-size: clamp(var(--font-size-3xl), 5vw, var(--font-size-5xl));
    font-weight: 800;
    margin-bottom: var(--spacing-md);
}

.cta-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
    line-height: 1.8;
}

.cta-features {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-2xl);
}

.cta-feature {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-size-base);
}

.cta-feature i {
    width: 20px;
    height: 20px;
    color: var(--color-accent-cyan);
}

.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.download-button {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-xl);
    text-decoration: none;
    color: var(--color-text-primary);
}

.download-button svg,
.download-button i {
    width: 32px;
    height: 32px;
}

.download-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

.download-store {
    font-size: var(--font-size-lg);
    font-weight: 700;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: rgba(15, 23, 42, 0.5);
    border-top: 1px solid var(--glass-border);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.footer-tagline {
    color: var(--color-text-secondary);
    max-width: 300px;
}

.social-links {
    display: flex;
    gap: var(--spacing-sm);
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-secondary);
    text-decoration: none;
}

.social-link i {
    width: 20px;
    height: 20px;
}

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

.footer-column {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-column h4 {
    font-size: var(--font-size-sm);
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-column a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: color 0.3s var(--transition-smooth);
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--glass-border);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.heart-icon {
    width: 14px;
    height: 14px;
    color: #f093fb;
    display: inline;
}

/* ============================================
   Scroll Reveal Animation
   ============================================ */
.reveal-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s var(--transition-smooth);
}

.reveal-on-scroll.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: var(--font-size-4xl);
    }
    
    .hero-subtitle {
        font-size: var(--font-size-base);
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline-item {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .timeline-number {
        width: 60px;
        height: 60px;
        font-size: var(--font-size-xl);
    }
    
    .gallery-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .cta-content {
        padding: var(--spacing-2xl) var(--spacing-lg);
    }
    
    .cta-features {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-3xl: 3rem;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    section {
        padding: var(--spacing-2xl) 0;
    }
}

/* ============================================
   Browser Compatibility (Graceful Degradation)
   ============================================ */
@supports not (backdrop-filter: blur(20px)) {
    .glass-card,
    .nav-glass {
        background: rgba(255, 255, 255, 0.2);
    }
}