/* CSS Variables */
:root {
    --color-bg: #0a0a0f;
    --color-bg-secondary: #12121a;
    --color-bg-card: #1a1a2e;
    --color-primary: #6366f1;
    --color-primary-hover: #4f46e5;
    --color-accent: #22d3ee;
    --color-text: #f8fafc;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #64748b;
    --color-border: #2d2d44;
    --color-success: #22c55e;
    --color-warning: #f59e0b;
    
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --border-radius: 12px;
    --border-radius-lg: 20px;
    --transition: 0.2s ease;
    
    --container-max: 1200px;
    --section-padding: 80px 0;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

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

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

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

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    font-size: 1.125rem;
}

.logo-icon {
    width: 36px;
    height: 36px;
    border-radius: 8px;
}

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

.nav-links a {
    color: var(--color-text-secondary);
    font-weight: 500;
    transition: color var(--transition);
}

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition);
}

/* Button */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.875rem;
    transition: all var(--transition);
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
}

/* Hero */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-secondary) 100%);
    overflow: hidden;
}

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

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 24px;
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: 40px;
    max-width: 480px;
}

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

.store-badge img {
    height: 48px;
    transition: transform var(--transition);
}

.store-badge:hover img {
    transform: scale(1.05);
}

/* Phone Mockup */
.phone-mockup {
    position: relative;
    width: 280px;
    height: 560px;
    background: #1a1a2e;
    border-radius: 40px;
    padding: 12px;
    box-shadow: 0 50px 100px rgba(0, 0, 0, 0.5);
    margin: 0 auto;
}

.phone-mockup::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 24px;
    background: #0a0a0f;
    border-radius: 12px;
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--color-bg);
    border-radius: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.mockup-content {
    text-align: center;
    padding: 20px;
}

.mockup-prompt {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 40px;
    color: var(--color-accent);
}

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

.mockup-btn {
    padding: 16px 32px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 1rem;
}

.mockup-btn.light {
    background: #f8fafc;
    color: #1a1a2e;
}

.mockup-btn.dark {
    background: #2d2d44;
    color: #f8fafc;
}

/* Sections */
section h2 {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 16px;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 1.125rem;
    margin-bottom: 48px;
}

/* Features */
.features {
    padding: var(--section-padding);
    background: var(--color-bg-secondary);
}

.features h2 {
    margin-bottom: 48px;
}

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

.feature-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: 32px;
    transition: transform var(--transition), border-color var(--transition);
}

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

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

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 8px;
}

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

/* Exercises */
.exercises {
    padding: var(--section-padding);
}

.exercise-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.exercise-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: 24px;
    position: relative;
}

.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
}

.badge-free {
    background: rgba(34, 197, 94, 0.15);
    color: var(--color-success);
}

.badge-pro {
    background: rgba(99, 102, 241, 0.15);
    color: var(--color-primary);
}

.exercise-card h3 {
    font-size: 1.125rem;
    margin-bottom: 8px;
}

.exercise-card p {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

/* Download */
.download {
    padding: var(--section-padding);
    background: linear-gradient(135deg, var(--color-bg-card) 0%, var(--color-bg-secondary) 100%);
    text-align: center;
}

.download h2 {
    margin-bottom: 12px;
}

.download > .container > p {
    color: var(--color-text-secondary);
    margin-bottom: 32px;
}

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

/* FAQ */
.faq {
    padding: var(--section-padding);
}

.faq h2 {
    margin-bottom: 48px;
}

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

.faq-item {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    margin-bottom: 12px;
    overflow: hidden;
}

.faq-item summary {
    padding: 20px 24px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    list-style: none;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    font-size: 1.5rem;
    color: var(--color-text-muted);
    transition: transform var(--transition);
}

.faq-item[open] summary::after {
    transform: rotate(45deg);
}

.faq-item p {
    padding: 0 24px 20px;
    color: var(--color-text-secondary);
}

.faq-item a {
    color: var(--color-primary);
}

.faq-item a:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-logo {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    margin-bottom: 16px;
}

.footer-brand p {
    color: var(--color-text-secondary);
    max-width: 280px;
}

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

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

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

.footer-links a {
    color: var(--color-text-secondary);
    transition: color var(--transition);
}

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

.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.footer-bottom p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

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

@media (max-width: 768px) {
    :root {
        --section-padding: 60px 0;
    }
    
    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--color-bg);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        border-bottom: 1px solid var(--color-border);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero {
        padding: 120px 0 60px;
    }
    
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        margin: 0 auto 32px;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .phone-mockup {
        width: 220px;
        height: 440px;
    }
    
    .mockup-prompt {
        font-size: 1.125rem;
    }
    
    .mockup-btn {
        padding: 12px 20px;
        font-size: 0.875rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .exercise-list {
        grid-template-columns: 1fr;
    }
    
    section h2 {
        font-size: 2rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 32px;
    }
    
    .footer-brand p {
        margin: 0 auto;
    }
}