/* ============================================
   Dataprixa Landing Page - CSS Stylesheet
   Modern, Responsive, SEO-Optimized Design
   ============================================ */

/* === CSS Variables for Theming === */
:root {
    /* Color Palette - Professional Tech Theme */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #0ea5e9;
    --accent-color: #06b6d4;
    
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-light: #6b7280;
    --text-white: #ffffff;
    
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-gray: #f3f4f6;
    --bg-dark: #1f2937;
    --bg-darker: #111827;
    
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 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);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* === Global Reset & Base Styles === */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-white);
    overflow-x: hidden;
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.75rem);
    letter-spacing: -0.01em;
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
}

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

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-base);
}

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

a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* === Container === */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* === Header === */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-md) 0;
    box-shadow: var(--shadow-sm);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
}

.logo-icon {
    font-size: 1.75rem;
}

.logo-text {
    letter-spacing: -0.02em;
}

/* === Hero Section === */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: var(--spacing-3xl) 0;
    text-align: center;
    color: var(--text-white);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    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"><defs><pattern id="grid" width="40" height="40" patternUnits="userSpaceOnUse"><path d="M 40 0 L 0 0 0 40" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
    margin-bottom: var(--spacing-lg);
    color: var(--text-white);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero-subtitle {
    font-size: clamp(1.125rem, 2.5vw, 1.375rem);
    line-height: 1.6;
    margin-bottom: var(--spacing-xl);
    color: rgba(255, 255, 255, 0.95);
    font-weight: 400;
}

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

/* === Buttons === */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    border-radius: 0.5rem;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    text-decoration: none;
}

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

.btn-primary:hover {
    background-color: var(--bg-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: var(--primary-dark);
}

.btn-primary-large {
    background-color: var(--primary-color);
    color: var(--text-white);
    padding: 1.125rem 2.5rem;
    font-size: 1.125rem;
    box-shadow: var(--shadow-lg);
}

.btn-primary-large:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
    color: var(--text-white);
}

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

.section-light {
    background-color: var(--bg-white);
}

.section-dark {
    background-color: var(--bg-dark);
    color: var(--text-white);
}

.section-dark h2,
.section-dark h3,
.section-dark h4 {
    color: var(--text-white);
}

.section-dark p {
    color: rgba(255, 255, 255, 0.85);
}

.section-gradient {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-white);
}

.section-gradient h2,
.section-gradient h3 {
    color: var(--text-white);
}

.section-gradient p {
    color: rgba(255, 255, 255, 0.9);
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-2xl);
}

.section-title {
    font-size: clamp(1.875rem, 4vw, 2.75rem);
    font-weight: 800;
    margin-bottom: var(--spacing-md);
}

.section-intro {
    font-size: clamp(1.125rem, 2vw, 1.25rem);
    line-height: 1.7;
    color: var(--text-secondary);
}

.section-dark .section-intro {
    color: rgba(255, 255, 255, 0.85);
}

/* === Content Block === */
.content-block {
    max-width: 900px;
    margin: 0 auto;
}

.content-block p {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.content-link {
    font-weight: 600;
    color: var(--primary-color);
    text-decoration: underline;
    text-underline-offset: 3px;
    transition: all var(--transition-base);
}

.content-link:hover {
    color: var(--primary-dark);
    text-decoration-thickness: 2px;
}

/* === Topics Grid === */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.topic-card {
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 1rem;
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
}

.topic-card:hover {
    transform: translateY(-4px);
    background-color: rgba(255, 255, 255, 0.08);
    box-shadow: var(--shadow-xl);
}

.topic-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.topic-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-white);
}

.topic-description {
    font-size: 1rem;
    line-height: 1.7;
    color: rgba(255, 255, 255, 0.85);
}

/* === Audience Grid === */
.audience-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.audience-card {
    background-color: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
}

.audience-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.audience-title {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.audience-description {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

/* === Principles Grid === */
.principles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.principle-card {
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 1rem;
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
}

.principle-card:hover {
    transform: translateY(-4px);
    background-color: rgba(255, 255, 255, 0.15);
    box-shadow: var(--shadow-xl);
}

.principle-number {
    font-size: 2rem;
    font-weight: 800;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-mono);
}

.principle-title {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-white);
}

.principle-description {
    font-size: 1rem;
    line-height: 1.7;
    color: rgba(255, 255, 255, 0.9);
}

/* === Value Content === */
.value-content {
    max-width: 900px;
    margin: 0 auto;
}

.value-block {
    margin-bottom: var(--spacing-xl);
}

.value-subtitle {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.value-block p {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

/* === CTA Section === */
.section-cta {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: var(--spacing-3xl) 0;
    text-align: center;
    color: var(--text-white);
}

.cta-content {
    max-width: 700px;
    margin: 0 auto;
}

.cta-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    color: var(--text-white);
}

.cta-description {
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    line-height: 1.7;
    margin-bottom: var(--spacing-xl);
    color: rgba(255, 255, 255, 0.95);
}

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

/* === Footer === */
.footer {
    background-color: var(--bg-darker);
    color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

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

.footer-brand {
    max-width: 400px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-white);
    margin-bottom: var(--spacing-md);
}

.footer-tagline {
    font-size: 1rem;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.7);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-lg);
}

.footer-section {
    display: flex;
    flex-direction: column;
}

.footer-heading {
    font-size: 0.875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-white);
    margin-bottom: var(--spacing-md);
}

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

.footer-list li {
    margin-bottom: var(--spacing-xs);
}

.footer-link,
.footer-link-external {
    font-size: 0.9375rem;
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-base);
}

.footer-link:hover,
.footer-link-external:hover {
    color: var(--text-white);
}

.footer-link-external {
    font-weight: 600;
}

.footer-bottom {
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.footer-copyright {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.6);
}

/* === Responsive Design === */
@media (max-width: 768px) {
    :root {
        --spacing-3xl: 3rem;
        --spacing-2xl: 2.5rem;
    }
    
    .header {
        padding: var(--spacing-sm) 0;
    }
    
    .hero {
        padding: var(--spacing-2xl) 0;
    }
    
    .section {
        padding: var(--spacing-2xl) 0;
    }
    
    .topics-grid,
    .audience-grid,
    .principles-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .footer-brand {
        max-width: 100%;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.9375rem;
    }
}

/* === Print Styles === */
@media print {
    .header,
    .footer,
    .hero-cta,
    .cta-button-group {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
    }
    
    .section {
        page-break-inside: avoid;
    }
}

/* === Accessibility === */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* Focus visible for keyboard navigation */
:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}