/* ============================================
   AdaptRun Landing Page Styles
   Design System: "Confident Calm"
   ============================================ */

:root {
    /* Colors */
    --primary: #3B82F6;
    --primary-dark: #2563EB;
    --secondary: #F97316;
    --accent: #8B5CF6;
    --success: #10B981;
    --error: #EF4444;
    --warning: #F59E0B;

    /* Neutrals */
    --background: #F8FAFC;
    --surface: #FFFFFF;
    --text-primary: #0F172A;
    --text-secondary: #64748B;
    --text-muted: #94A3B8;
    --border: #E2E8F0;
    --divider: #F1F5F9;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #3B82F6 0%, #8B5CF6 100%);
    --gradient-hero: linear-gradient(180deg, #F8FAFC 0%, #EFF6FF 100%);

    /* 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);

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* ============================================
   Reset & Base
   ============================================ */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

/* ============================================
   Layout
   ============================================ */

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

.section-header {
    text-align: center;
    max-width: 640px;
    margin: 0 auto var(--space-3xl);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

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

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 14px;
}

.logo-text {
    font-weight: 700;
    font-size: 1.25rem;
}

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

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s;
}

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
}

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

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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    text-decoration: none;
}

.btn-sm {
    height: 40px;
    padding: 0 var(--space-lg);
    font-size: 14px;
}

.btn-lg {
    height: 52px;
    padding: 0 var(--space-xl);
    font-size: 16px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 14px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.5);
}

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

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

.btn-block {
    width: 100%;
}

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

.hero {
    position: relative;
    padding: 140px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient-hero);
    z-index: -1;
}

.hero-bg::after {
    content: '';
    position: absolute;
    top: 50%;
    right: -200px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-lg);
}

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

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--space-xl);
    max-width: 480px;
}

.hero-cta {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-2xl);
}

.hero-stats {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-primary);
}

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

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--border);
}

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

.phone-mockup {
    width: 280px;
    height: 560px;
    background: var(--text-primary);
    border-radius: 40px;
    padding: 12px;
    box-shadow: var(--shadow-xl), 0 0 0 1px rgba(0,0,0,0.1);
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--background);
    border-radius: 32px;
    padding: var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-xl);
}

.app-date {
    font-size: 1.75rem;
    font-weight: 700;
}

.streak-badge {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.875rem;
}

.workout-card {
    background: var(--surface);
    border-radius: var(--radius-xl);
    padding: var(--space-lg);
    box-shadow: var(--shadow-md);
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.workout-type {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

.workout-distance {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: var(--space-sm);
}

.workout-details {
    display: flex;
    gap: var(--space-sm);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.cta-button {
    background: var(--gradient-primary);
    color: white;
    text-align: center;
    padding: var(--space-md);
    border-radius: var(--radius-md);
    font-weight: 600;
}

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

.features {
    padding: var(--space-3xl) 0;
    background: var(--surface);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.feature-card {
    padding: var(--space-xl);
    border-radius: var(--radius-xl);
    background: var(--background);
    transition: all 0.3s;
}

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

.feature-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
}

.feature-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.feature-desc {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ============================================
   How It Works Section
   ============================================ */

.how-it-works {
    padding: var(--space-3xl) 0;
}

.steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-xl);
}

.step {
    text-align: center;
}

.step-number {
    width: 56px;
    height: 56px;
    background: var(--gradient-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto var(--space-lg);
}

.step-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.step-desc {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ============================================
   Pricing Section
   ============================================ */

.pricing {
    padding: var(--space-3xl) 0;
    background: var(--surface);
}

.pricing-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
    max-width: 1000px;
    margin: 0 auto;
}

.pricing-card {
    background: var(--background);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    position: relative;
}

.pricing-card-featured {
    background: var(--text-primary);
    color: white;
    transform: scale(1.05);
}

.pricing-card-featured .pricing-name,
.pricing-card-featured .price {
    color: white;
}

.pricing-card-featured .period,
.pricing-card-featured .pricing-features li {
    color: rgba(255, 255, 255, 0.7);
}

.pricing-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--secondary);
    color: white;
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

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

.pricing-name {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.pricing-price {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: var(--space-xs);
}

.price {
    font-size: 2.5rem;
    font-weight: 800;
}

.period {
    color: var(--text-muted);
}

.pricing-savings {
    color: var(--success);
    font-weight: 600;
    font-size: 0.875rem;
    margin-top: var(--space-sm);
}

.pricing-features {
    list-style: none;
    margin-bottom: var(--space-xl);
}

.pricing-features li {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) 0;
    color: var(--text-secondary);
}

.pricing-features svg {
    flex-shrink: 0;
}

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

.download {
    padding: var(--space-3xl) 0;
    background: var(--gradient-primary);
}

.download-content {
    text-align: center;
    color: white;
}

.download-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: var(--space-md);
}

.download-subtitle {
    font-size: 1.125rem;
    opacity: 0.9;
    margin-bottom: var(--space-xl);
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
}

.store-button {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    background: rgba(0, 0, 0, 0.3);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    transition: all 0.2s;
}

.store-button:hover {
    background: rgba(0, 0, 0, 0.5);
    transform: translateY(-2px);
}

.store-text {
    display: flex;
    flex-direction: column;
    text-align: left;
}

.store-label {
    font-size: 0.75rem;
    opacity: 0.8;
}

.store-name {
    font-size: 1.125rem;
    font-weight: 600;
}

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

.footer {
    background: var(--text-primary);
    color: white;
    padding: var(--space-3xl) 0 var(--space-xl);
}

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

.footer-brand .logo-text {
    color: white;
}

.footer-tagline {
    color: rgba(255, 255, 255, 0.6);
    margin-top: var(--space-md);
}

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

.footer-column h4 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: rgba(255, 255, 255, 0.5);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-column a {
    display: block;
    color: rgba(255, 255, 255, 0.8);
    padding: var(--space-xs) 0;
    transition: color 0.2s;
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
}

.social-links {
    display: flex;
    gap: var(--space-md);
}

.social-links a {
    color: rgba(255, 255, 255, 0.6);
    transition: color 0.2s;
}

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

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

@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-subtitle {
        max-width: none;
    }

    .hero-cta {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-image {
        order: -1;
    }

    .phone-mockup {
        width: 240px;
        height: 480px;
    }

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

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

    .pricing-cards {
        grid-template-columns: 1fr;
        max-width: 400px;
    }

    .pricing-card-featured {
        transform: none;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

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

    .hero-title {
        font-size: 2.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

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

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

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

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

    .footer-bottom {
        flex-direction: column;
        gap: var(--space-md);
        text-align: center;
    }

    .download-buttons {
        flex-direction: column;
        align-items: center;
    }

    .store-button {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-cta {
        flex-direction: column;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-md);
    }

    .stat-divider {
        display: none;
    }

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