/* ===========================
   CSS Variables & Reset
   =========================== */

:root {
    /* Colors */
    --color-primary: #007AFF;
    --color-primary-dark: #0051D5;
    --color-secondary: #5856D6;
    --color-accent: #FF9500;
    --color-success: #34C759;
    --color-danger: #FF3B30;
    --color-warning: #FFCC00;
    
    /* Gradients */
    --gradient-blue: linear-gradient(135deg, #007AFF 0%, #00C6FF 100%);
    --gradient-purple: linear-gradient(135deg, #8B5CF6 0%, #EC4899 100%);
    --gradient-orange: linear-gradient(135deg, #FF9500 0%, #FF3B30 100%);
    --gradient-teal: linear-gradient(135deg, #5AC8FA 0%, #34C759 100%);
    --gradient-red: linear-gradient(135deg, #FF9500 0%, #FFCC00 100%);
    --gradient-green: linear-gradient(135deg, #34C759 0%, #30D158 100%);
    
    /* Neutral Colors */
    --color-text-primary: #1C1C1E;
    --color-text-secondary: #6E6E73;
    --color-text-tertiary: #A1A1A6;
    --color-background: #FFFFFF;
    --color-background-secondary: #F5F5F7;
    --color-background-tertiary: #E5E5EA;
    --color-border: #D1D1D6;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.15);
    
    /* Transitions */
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

section {
    padding: var(--spacing-2xl) 0;
}

/* ===========================
   Navigation
   =========================== */

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

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.25rem;
    font-weight: 600;
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--color-text-primary);
    font-weight: 500;
    transition: var(--transition);
}

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.hamburger span {
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    transition: var(--transition);
}

/* ===========================
   Buttons
   =========================== */

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 12px 24px;
    border-radius: var(--radius-lg);
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.125rem;
}

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

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

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

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

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

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

/* ===========================
   Hero Section
   =========================== */

.hero {
    position: relative;
    padding: 120px 0 80px;
    overflow: hidden;
    background: linear-gradient(135deg, #F5F7FA 0%, #E8F0FE 100%);
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="2" fill="%23007AFF" opacity="0.1"/></svg>');
    opacity: 0.5;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero-text {
    animation: fadeInUp 0.8s ease;
}

.badge {
    display: inline-block;
    padding: 6px 12px;
    background: var(--gradient-purple);
    color: white;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    background: var(--gradient-blue);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeInRight 0.8s ease;
}

.phone-mockup {
    width: 300px;
    height: 600px;
    background: white;
    border-radius: 40px;
    box-shadow: var(--shadow-xl);
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.phone-mockup::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 30px;
    background: black;
    border-radius: 0 0 20px 20px;
}

.app-icon-large {
    width: 120px;
    height: 120px;
    background: var(--gradient-blue);
    border-radius: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
}

.icon-symbol {
    font-size: 4rem;
}

/* ===========================
   Section Headers
   =========================== */

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

.section-badge {
    display: inline-block;
    padding: 6px 16px;
    background: var(--color-background-secondary);
    color: var(--color-primary);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
}

/* ===========================
   Features Section
   =========================== */

.features {
    background: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    padding: var(--spacing-lg);
    background: var(--color-background-secondary);
    border-radius: var(--radius-lg);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

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

.feature-card.premium {
    border: 2px solid transparent;
    background: linear-gradient(white, white) padding-box,
                linear-gradient(135deg, #FFD700, #FFA500) border-box;
}

.feature-icon {
    width: 64px;
    height: 64px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    font-size: 1.75rem;
    color: white;
}

.purple-gradient { background: var(--gradient-purple); }
.blue-gradient { background: var(--gradient-blue); }
.orange-gradient { background: var(--gradient-orange); }
.teal-gradient { background: var(--gradient-teal); }
.red-gradient { background: var(--gradient-red); }
.green-gradient { background: var(--gradient-green); }

.feature-card h3 {
    font-size: 1.375rem;
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.premium-badge {
    font-size: 1rem;
}

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

/* ===========================
   Screenshots Section
   =========================== */

.screenshots {
    background: var(--color-background-secondary);
}

.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.screenshot-placeholder {
    aspect-ratio: 9 / 19.5;
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.placeholder-content {
    text-align: center;
    color: var(--color-text-tertiary);
}

.placeholder-content i {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.placeholder-content p {
    font-weight: 600;
}

.screenshots-note {
    text-align: center;
    color: var(--color-text-tertiary);
    font-style: italic;
}

/* ===========================
   Technology Section
   =========================== */

.technology {
    background: white;
}

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

.tech-card {
    padding: var(--spacing-lg);
    background: var(--color-background-secondary);
    border-radius: var(--radius-md);
    text-align: center;
    transition: var(--transition);
}

.tech-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.tech-card i {
    font-size: 2.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.tech-card h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.tech-card p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
}

/* ===========================
   Developer Section
   =========================== */

.developer {
    background: var(--color-background-secondary);
}

.developer-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-xl);
    align-items: center;
    background: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.developer-image {
    display: flex;
    justify-content: center;
}

.avatar {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: var(--gradient-blue);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 5rem;
    color: white;
    box-shadow: var(--shadow-lg);
}

.developer-info h3 {
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
}

.developer-role {
    color: var(--color-primary);
    font-weight: 600;
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

.developer-bio {
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.developer-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--color-background-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-primary);
    font-size: 1.25rem;
    transition: var(--transition);
    text-decoration: none;
}

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

/* ===========================
   Credits Section
   =========================== */

.credits {
    background: white;
}

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

.credit-card {
    padding: var(--spacing-lg);
    background: var(--color-background-secondary);
    border-radius: var(--radius-md);
    text-align: center;
}

.credit-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.credit-card p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.credit-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.credit-link:hover {
    gap: var(--spacing-sm);
}

/* ===========================
   Download Section
   =========================== */

.download {
    background: var(--gradient-blue);
    color: white;
    text-align: center;
}

.download-content h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.download-content p {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

.download-note {
    margin-top: var(--spacing-md);
    font-size: 0.9375rem;
    opacity: 0.8;
}

/* ===========================
   Footer
   =========================== */

.footer {
    background: var(--color-text-primary);
    color: white;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    text-align: center;
}

.footer-content {
    margin-bottom: var(--spacing-lg);
}

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.footer-tagline {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
    opacity: 0.9;
}

.footer-copyright,
.footer-attribution {
    font-size: 0.875rem;
    opacity: 0.7;
    margin-top: var(--spacing-xs);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-links a {
    color: white;
    text-decoration: none;
    opacity: 0.8;
    transition: var(--transition);
}

.footer-links a:hover {
    opacity: 1;
}

/* ===========================
   Animations
   =========================== */

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

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* ===========================
   Responsive Design
   =========================== */

@media (max-width: 968px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .developer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .developer-links {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        transition: var(--transition);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-lg);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero {
        padding: 100px 0 60px;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.25rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
    
    .phone-mockup {
        width: 250px;
        height: 500px;
    }
    
    .avatar {
        width: 150px;
        height: 150px;
        font-size: 4rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn-large {
        width: 100%;
        justify-content: center;
    }
    
    .screenshots-grid {
        grid-template-columns: 1fr;
    }
}