/* CSS Custom Properties for Theme Support */
:root {
  /* Light Theme Colors */
  --primary-color: #2563eb;
  --secondary-color: #7c3aed;
  --accent-color: #06b6d4;
  --background-color: #ffffff;
  --surface-color: #f8fafc;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border-color: #e2e8f0;
  --shadow-color: rgba(0, 0, 0, 0.1);
  --shadow-color-strong: rgba(0, 0, 0, 0.15);
  
  /* Typography */
  --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  --font-size-6xl: 3.75rem;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;
  
  /* Borders */
  --border-radius-sm: 0.375rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  --border-radius-full: 9999px;
  
  /* Animations */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
}

/* Dark Theme Colors */
[data-theme="dark"] {
  --primary-color: #3b82f6;
  --secondary-color: #8b5cf6;
  --accent-color: #22d3ee;
  --background-color: #0f172a;
  --surface-color: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --border-color: #334155;
  --shadow-color: rgba(0, 0, 0, 0.3);
  --shadow-color-strong: rgba(0, 0, 0, 0.5);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background-color);
  transition: background-color var(--transition-base), color var(--transition-base);
  overflow-x: hidden;
}

/* Skip Link for Accessibility */
.skip-link {
  position: absolute;
  top: -50px;
  left: 6px;
  background: var(--primary-color);
  color: white;
  padding: 8px;
  text-decoration: none;
  border-radius: var(--border-radius-sm);
  z-index: 1000;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 6px;
}

/* Theme Toggle */
.theme-toggle {
  position: fixed;
  top: var(--spacing-lg);
  right: var(--spacing-lg);
  z-index: 100;
}

.theme-toggle-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-full);
  cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: 0 2px 8px var(--shadow-color);
}

.theme-toggle-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 12px var(--shadow-color-strong);
}

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
  stroke: var(--text-primary);
  transition: all var(--transition-base);
}

/* Hide/show icons based on theme */
[data-theme="light"] .moon-icon,
[data-theme="dark"] .sun-icon {
  display: none;
}

/* Header Styles */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(248, 250, 252, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  z-index: 50;
  transition: all var(--transition-base);
}

[data-theme="dark"] .header {
  background: rgba(15, 23, 42, 0.8);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo svg {
  height: 40px;
  width: auto;
  color: var(--text-primary);
  transition: color var(--transition-base);
}

.nav-links {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius-md);
  transition: all var(--transition-base);
}

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

.nav-link svg {
  width: 12px;
  height: 12px;
  opacity: 0.7;
}

/* Main Content */
.main {
  padding-top: 70px; /* Account for fixed header */
}

/* Hero Section */
.hero {
  position: relative;
  min-height: calc(100vh - 70px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-4xl) var(--spacing-lg);
  overflow: hidden;
}

.hero-container {
  max-width: 1200px;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-4xl);
  align-items: center;
  position: relative;
  z-index: 2;
}

/* Hero Background Animation */
.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  pointer-events: none;
  z-index: 1;
}

.floating-element {
  position: absolute;
  border-radius: 50%;
  background: linear-gradient(45deg, var(--primary-color), var(--accent-color));
  opacity: 0.1;
  animation: float 6s ease-in-out infinite;
}

.floating-element-1 {
  width: 200px;
  height: 200px;
  top: 10%;
  left: 10%;
  animation-delay: 0s;
}

.floating-element-2 {
  width: 150px;
  height: 150px;
  top: 60%;
  right: 20%;
  animation-delay: 2s;
}

.floating-element-3 {
  width: 100px;
  height: 100px;
  bottom: 20%;
  left: 60%;
  animation-delay: 4s;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(180deg);
  }
}

/* Hero Content */
.hero-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: 700;
  line-height: 1.1;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
}

.gradient-text {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color), var(--accent-color));
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: gradient-shift 3s ease infinite;
}

@keyframes gradient-shift {
  0%, 100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 500px;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

/* Button Styles */
.cta-button {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-base);
  border: 2px solid transparent;
  cursor: pointer;
  font-size: var(--font-size-base);
}

.cta-button.primary {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.cta-button.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.4);
}

.cta-button svg {
  width: 16px;
  height: 16px;
  transition: transform var(--transition-base);
}

.cta-button:hover svg {
  transform: translateX(2px);
}

/* Hero Illustration */
.hero-illustration {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-illustration svg {
  width: 100%;
  height: auto;
  max-width: 400px;
  color: var(--text-secondary);
}

/* About Section */
.about {
  padding: var(--spacing-4xl) var(--spacing-lg);
  background-color: var(--surface-color);
}

.about-container {
  max-width: 1200px;
  margin: 0 auto;
}

.about-content {
  text-align: center;
  margin-bottom: var(--spacing-4xl);
}

.about-title {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xl);
}

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

.about-text p {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--spacing-lg);
}

.about-text strong {
  color: var(--primary-color);
  font-weight: 600;
}

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

.feature-card {
  background: var(--background-color);
  padding: var(--spacing-2xl);
  border-radius: var(--border-radius-xl);
  text-align: center;
  border: 1px solid var(--border-color);
  transition: all var(--transition-base);
  box-shadow: 0 2px 8px var(--shadow-color);
  opacity: 0;
  transform: translateY(20px);
}

.feature-card.animate-in {
  opacity: 1;
  transform: translateY(0);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px var(--shadow-color-strong);
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  border-radius: var(--border-radius-lg);
  margin-bottom: var(--spacing-lg);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
  stroke: white;
}

.feature-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.feature-description {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Footer */
.footer {
  background-color: var(--surface-color);
  border-top: 1px solid var(--border-color);
  padding: var(--spacing-3xl) var(--spacing-lg) var(--spacing-xl);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
}

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

.footer-section {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.footer-logo svg {
  height: 32px;
  width: auto;
  color: var(--text-primary);
}

.footer-description {
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 300px;
}

.footer-heading {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-md);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-base);
}

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

.footer-link svg {
  width: 12px;
  height: 12px;
  opacity: 0.7;
}

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

.footer-copyright {
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

/* Animation Classes */
.animate-in {
  opacity: 1 !important;
  transform: translateY(0) !important;
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

/* Responsive Design - Mobile First Approach */

/* Small devices (landscape phones, 576px and up) */
@media (max-width: 576px) {
  :root {
    --font-size-5xl: 2rem;
    --font-size-4xl: 1.75rem;
    --spacing-4xl: 3rem;
  }
  
  .nav-container {
    padding: 0 var(--spacing-md);
  }
  
  .theme-toggle {
    top: var(--spacing-md);
    right: var(--spacing-md);
  }
  
  .theme-toggle-btn {
    width: 40px;
    height: 40px;
  }
  
  .hero {
    padding: var(--spacing-2xl) var(--spacing-md);
  }
  
  .hero-container {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
    text-align: center;
  }
  
  .hero-title {
    font-size: var(--font-size-4xl);
  }
  
  .hero-description {
    font-size: var(--font-size-base);
  }
  
  .hero-illustration {
    order: -1;
  }
  
  .hero-illustration svg {
    max-width: 280px;
  }
  
  .about {
    padding: var(--spacing-2xl) var(--spacing-md);
  }
  
  .features-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
  
  .feature-card {
    padding: var(--spacing-xl);
  }
  
  .footer {
    padding: var(--spacing-2xl) var(--spacing-md) var(--spacing-lg);
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    text-align: center;
  }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 577px) and (max-width: 768px) {
  .hero-container {
    grid-template-columns: 1fr;
    gap: var(--spacing-3xl);
    text-align: center;
  }
  
  .hero-illustration {
    order: -1;
  }
  
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
  .hero-container {
    gap: var(--spacing-4xl);
  }
  
  .features-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
  .hero-title {
    font-size: var(--font-size-6xl);
  }
  
  .hero-description {
    font-size: var(--font-size-xl);
  }
}

/* High DPI / Retina displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  /* Optimize for high-resolution displays */
  .hero-illustration svg,
  .feature-icon svg,
  .logo svg {
    shape-rendering: geometricPrecision;
  }
}

/* Reduced motion for accessibility */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  .floating-element {
    animation: none;
  }
  
  .gradient-text {
    animation: none;
    background: var(--primary-color);
    -webkit-background-clip: text;
    background-clip: text;
  }
}

/* Focus styles for accessibility */
a:focus,
button:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-color-strong: rgba(0, 0, 0, 0.5);
    --border-color: #666666;
  }
  
  [data-theme="dark"] {
    --border-color: #999999;
  }
}

/* Print styles */
@media print {
  .theme-toggle,
  .floating-element,
  .hero-bg {
    display: none !important;
  }
  
  .header {
    position: static;
    background: white !important;
    border-bottom: 1px solid #000;
  }
  
  .main {
    padding-top: 0;
  }
  
  body {
    color: #000 !important;
    background: white !important;
  }
  
  .hero,
  .about,
  .footer {
    break-inside: avoid;
  }
}