/* Lemma Design System - Clean & Minimal */
/* Nuclear Reset - Single Source of Truth */

/* === 1. CSS RESET === */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* === 2. DESIGN TOKENS === */
:root {
    /* Colors - Authentic Brand Purple Theme (from logo) */
    --primary: #667eea;
    --primary-dark: #5a67d8;
    --primary-light: #7c3aed;
    --primary-500: #6366f1;
    --primary-600: #5b5bf6;
    --primary-700: #4f46e5;
    --secondary: #764ba2;
    --accent: #6366f1;
    
    /* Neutrals - Sophisticated grayscale */
    --black: #0f172a;
    --gray-900: #1e293b;
    --gray-800: #334155;
    --gray-700: #475569;
    --gray-600: #64748b;
    --gray-500: #94a3b8;
    --gray-400: #cbd5e1;
    --gray-300: #e2e8f0;
    --gray-200: #f1f5f9;
    --gray-100: #f8fafc;
    --white: #ffffff;
    
    /* Semantic colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* Spacing - 8pt grid system */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;
    --space-10: 40px;
    --space-12: 48px;
    --space-16: 64px;
    --space-20: 80px;
    --space-24: 96px;
    
    /* Typography - Human-centered scale */
    --font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: "Source Code Pro", "SF Mono", Consolas, monospace;
    --font-size-xs: 13px;
    --font-size-sm: 15px;
    --font-size-base: 17px;
    --font-size-lg: 19px;
    --font-size-xl: 22px;
    --font-size-2xl: 28px;
    --font-size-3xl: 36px;
    --font-size-4xl: 48px;
    
    /* Layout */
    --container-max-width: 1200px;
    --border-radius: 6px;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

/* === 3. BASE STYLES === */
html {
    font-size: var(--font-size-base);
    line-height: 1.6;
}

body {
    font-family: var(--font-family);
    color: var(--gray-700);
    background-color: var(--white);
    line-height: 1.6;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--gray-900);
    font-weight: 600;
    line-height: 1.25;
    margin-bottom: var(--space-4);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }

p {
    margin-bottom: var(--space-4);
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.15s ease;
}

a:hover {
    color: var(--primary-dark);
}

/* === 4. LAYOUT COMPONENTS === */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.section {
    padding: var(--space-16) 0;
}

/* === 5. NAVIGATION === */
.nav-header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 24px;
    width: 100%;
    gap: 40px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--gray-900);
    text-decoration: none;
    transition: opacity 0.15s ease;
}

.nav-logo:hover {
    opacity: 0.8;
    color: var(--gray-900);
}

.nav-logo-icon {
    width: 36px;
    height: 36px;
}

.nav-center {
    display: flex;
    gap: 40px;
    align-items: center;
    flex: 1;
    justify-content: flex-start;
    margin-left: 60px;
    max-width: 600px;
}

.nav-right {
    display: flex;
    gap: 16px;
    align-items: center;
    margin-left: auto;
    flex-shrink: 0;
}

.nav-link {
    color: var(--gray-700);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-base);
    transition: color 0.15s ease;
    padding: 8px 4px;
}

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

/* Mobile Navigation */
@media (max-width: 768px) {
    .nav-container {
        gap: 20px;
    }
    
    .nav-center {
        display: none;
    }
    
    .nav-right {
        gap: 12px;
    }
    
    .nav-right .btn {
        padding: 8px 16px;
        font-size: var(--font-size-sm);
    }
    
    .nav-logo-icon {
        width: 28px;
        height: 28px;
    }
}

/* === 6. BUTTONS === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    font-family: var(--font-family);
    font-weight: 500;
    font-size: var(--font-size-base);
    text-decoration: none;
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.15s ease;
    letter-spacing: -0.01em;
}

.btn-icon {
    font-size: 16px;
    line-height: 1;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: var(--white);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.25);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.35);
    color: var(--white);
}

.btn-secondary {
    background: var(--white);
    color: var(--gray-700);
    border: 1px solid var(--gray-300);
}

.btn-secondary:hover {
    background: var(--gray-100);
    border-color: var(--primary);
    color: var(--primary-dark);
}

/* === 7. CARDS === */
.card {
    background: var(--white);
    border-radius: 12px;
    border: 1px solid var(--gray-200);
    padding: 32px;
    margin-bottom: var(--space-6);
    transition: all 0.2s ease;
}

.card:hover {
    border-color: var(--gray-300);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transform: translateY(-2px);
}

.card-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 16px;
    line-height: 1.3;
}

/* === 8. FORMS === */
.form-group {
    margin-bottom: var(--space-6);
}

.form-label {
    display: block;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: var(--space-2);
}

.form-input {
    width: 100%;
    padding: var(--space-3);
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius);
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    transition: border-color 0.2s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* === 9. HERO SECTIONS === */
.hero {
    background: linear-gradient(135deg, var(--gray-900) 0%, var(--black) 100%);
    color: var(--white);
    padding: 80px 0 100px;
    text-align: center;
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at center top, rgba(102, 126, 234, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero h1 {
    color: var(--white);
    font-size: clamp(32px, 5vw, 56px);
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
    line-height: 1.1;
}

.hero p {
    font-size: var(--font-size-xl);
    color: var(--gray-400);
    max-width: 580px;
    margin: 0 auto 40px;
    line-height: 1.5;
    font-weight: 400;
}

/* === 10. UTILITY CLASSES === */
.text-center { text-align: center; }
.text-primary { color: var(--primary); }
.text-secondary { color: var(--secondary); }
.text-gray { color: var(--gray-600); }
.text-muted { color: var(--gray-500); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

/* === 11. ADDITIONAL AUTHENTIC STYLING === */
/* Subtle gradients and shadows for depth */
.section:nth-child(even) {
    background: linear-gradient(180deg, var(--gray-100) 0%, var(--white) 100%);
}

/* More natural spacing and rhythm */
h2 {
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 20px;
}

h3 {
    font-weight: 600;
    letter-spacing: -0.01em;
}

/* Professional link styling */
.nav-link {
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: all 0.2s ease;
    transform: translateX(-50%);
}

.nav-link:hover::after {
    width: 100%;
}

/* === 12. RESPONSIVE === */
@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
    
    .hero h1 {
        font-size: var(--font-size-3xl);
    }
    
    .hero {
        padding: 60px 0 80px;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .nav-center {
        gap: 24px;
    }
}