/* CSS Variables for Design System */
:root {
  /* Colors - Light Mode */
  --color-primary: #007AFF;
  --color-success: #34C759;
  --color-warning: #FF9500;
  --color-focus: #AF52DE;
  --color-text-primary: #1D1D1F;
  --color-text-secondary: #86868B;
  --color-background: #FFFFFF;
  --color-surface: #F5F5F7;
  --color-border: #D2D2D7;
  --color-hover: #F5F5F7;
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Helvetica Neue', Arial, sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;
  --font-size-3xl: 32px;
  --font-size-4xl: 48px;
  --font-size-5xl: 64px;
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  
  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  /* Transitions */
  --transition-fast: 0.15s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --transition-normal: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --transition-slow: 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --color-text-primary: #F5F5F7;
  --color-text-secondary: #A1A1A6;
  --color-background: #000000;
  --color-surface: #1D1D1F;
  --color-border: #424245;
  --color-hover: #2C2C2E;
  --color-preview-overlay: linear-gradient(135deg, rgba(0, 122, 255, 0.9) 0%, rgba(175, 82, 222, 0.9) 100%);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-background);
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

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

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

a:hover {
  color: var(--color-focus);
}

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

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: all var(--transition-normal);
}

[data-theme="dark"] .navbar {
  background-color: rgba(0, 0, 0, 0.8);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
}

.nav-brand h1 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin: 0;
}

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

.nav-link {
  font-size: var(--font-size-base);
  font-weight: 500;
  color: var(--color-text-primary);
  transition: color var(--transition-fast);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);
}

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

/* Theme Toggle */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  border-radius: var(--radius-sm);
  color: var(--color-text-primary);
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-toggle:hover {
  background-color: var(--color-hover);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

.sun-icon {
  display: none;
}

[data-theme="dark"] .sun-icon {
  display: block;
}

[data-theme="dark"] .moon-icon {
  display: none;
}

/* Hero Section */
.hero {
  padding: 160px 0 120px;
  background: linear-gradient(135deg, var(--color-surface) 0%, var(--color-background) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 30% 70%, rgba(0, 122, 255, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 800px;
  text-align: center;
  margin: 0 auto;
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.1;
  animation: fadeInUp 0.8s ease-out;
}

.hero-subtitle {
  font-size: var(--font-size-2xl);
  color: var(--color-primary);
  margin-bottom: var(--spacing-xl);
  font-weight: 500;
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-2xl);
  line-height: 1.7;
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease-out 0.6s both;
}

.cta-button {
  padding: var(--spacing-md) var(--spacing-2xl);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-lg);
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-normal);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 160px;
}

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

.cta-button.primary:hover {
  background-color: #0051D5;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.cta-button.secondary {
  background-color: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.cta-button.secondary:hover {
  background-color: var(--color-primary);
  color: white;
  transform: translateY(-2px);
}

/* Services Section */
.services {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-background);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

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

.section-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--spacing-2xl);
  margin-top: var(--spacing-3xl);
}

.service-card {
  background-color: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.service-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.service-card.featured {
  border-color: var(--color-primary);
  background: linear-gradient(135deg, var(--color-surface) 0%, rgba(0, 122, 255, 0.05) 100%);
}

.service-badge {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  background-color: var(--color-primary);
  color: white;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.service-icon {
  width: 64px;
  height: 64px;
  background-color: var(--color-primary);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-lg);
  color: white;
}

.service-icon svg {
  width: 32px;
  height: 32px;
}

.service-title {
  font-size: var(--font-size-2xl);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.service-price {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
}

.service-description {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.6;
}

.service-features {
  margin-bottom: var(--spacing-lg);
}

.feature-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-secondary);
}

.feature-item svg {
  width: 16px;
  height: 16px;
  color: var(--color-success);
  flex-shrink: 0;
}

.service-cta {
  display: inline-block;
  background-color: var(--color-primary);
  color: white;
  padding: var(--spacing-md) var(--spacing-xl);
  border-radius: var(--radius-lg);
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-normal);
  width: 100%;
  text-align: center;
}

.service-cta:hover {
  background-color: #0051D5;
  transform: translateY(-2px);
  color: white;
}

/* About Section */
.about {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-surface);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

.about-text {
  padding-right: var(--spacing-xl);
}

.about-description {
  margin-bottom: var(--spacing-xl);
}

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

.philosophy {
  background-color: var(--color-background);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--color-primary);
}

.philosophy h3 {
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-md);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: var(--spacing-lg);
}

.stat-item {
  text-align: center;
  padding: var(--spacing-xl);
  background-color: var(--color-background);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.stat-number {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

/* Contact Section */
.contact {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-background);
}

.contact-content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--spacing-3xl);
  margin-top: var(--spacing-2xl);
}

.contact-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.contact-item {
  background-color: var(--color-surface);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
}

.contact-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.contact-item h3 {
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
  font-size: var(--font-size-lg);
}

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

.contact-link {
  display: inline-block;
  background-color: var(--color-primary);
  color: white;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition-normal);
}

.contact-link:hover {
  background-color: #0051D5;
  transform: translateY(-1px);
  color: white;
}

.contact-note {
  background-color: var(--color-surface);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.contact-note h3 {
  color: var(--color-warning);
  margin-bottom: var(--spacing-md);
}

.contact-note p {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-sm);
  font-size: var(--font-size-sm);
  line-height: 1.6;
}

/* Knowledge Base Preview */
.knowledge-base-preview {
  margin: var(--spacing-lg) 0;
  padding: var(--spacing-lg);
  background-color: var(--color-background);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
}

.service-card:hover .knowledge-base-preview {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.preview-title {
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.preview-title::before {
  content: '';
  width: 4px;
  height: 20px;
  background-color: var(--color-primary);
  border-radius: 2px;
}

.preview-image-container {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: var(--spacing-md);
  background-color: var(--color-surface);
}

.preview-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform var(--transition-normal);
  display: block;
}

.preview-image-container:hover .preview-image {
  transform: scale(1.05);
}

.preview-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-preview-overlay, linear-gradient(135deg, rgba(0, 122, 255, 0.8) 0%, rgba(175, 82, 222, 0.8) 100%));
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.preview-image-container:hover .preview-overlay {
  opacity: 1;
}

.preview-button {
  background: rgba(255, 255, 255, 0.95);
  border: none;
  border-radius: var(--radius-md);
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  transition: all var(--transition-fast);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.preview-button:hover {
  background: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.preview-button svg {
  width: 16px;
  height: 16px;
}

.preview-description {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin: 0;
}

/* Image Loading States */
.preview-image-container {
  position: relative;
}

.preview-image-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, var(--color-surface) 25%, var(--color-hover) 50%, var(--color-surface) 75%);
  background-size: 200% 100%;
  animation: loading 1.5s infinite;
  z-index: 1;
}

.preview-image-container img {
  position: relative;
  z-index: 2;
}

.preview-image-container img.loaded {
  z-index: 3;
}

.preview-image-container img.loaded + .preview-overlay {
  z-index: 4;
}

@keyframes loading {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

/* Footer */
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
}

.footer-brand h3 {
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.footer-brand p {
  color: var(--color-text-secondary);
  margin: 0;
}

.footer-links {
  display: flex;
  gap: var(--spacing-lg);
}

.footer-link {
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

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

.footer-bottom p {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  margin: 0;
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* Responsive Design */
@media (max-width: 1024px) {
  .hero-title {
    font-size: var(--font-size-4xl);
  }
  
  .about-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
  }
  
  .about-text {
    padding-right: 0;
  }
  
  .contact-content {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-container {
    padding: 0 var(--spacing-md);
  }
  
  .hero {
    padding: 120px 0 80px;
  }
  
  .hero-title {
    font-size: var(--font-size-3xl);
  }
  
  .hero-subtitle {
    font-size: var(--font-size-xl);
  }
  
  .hero-cta {
    flex-direction: column;
    align-items: center;
  }
  
  .cta-button {
    width: 100%;
    max-width: 280px;
  }
  
  .services-grid {
    grid-template-columns: 1fr;
  }
  
  .about-stats {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .contact-info {
    grid-template-columns: 1fr;
  }
  
  .footer-content {
    flex-direction: column;
    gap: var(--spacing-lg);
    text-align: center;
  }
  
  /* Knowledge base preview responsive */
  .knowledge-base-preview {
    padding: var(--spacing-md);
    margin: var(--spacing-md) 0;
  }
  
  .preview-image {
    height: 150px;
  }
  
  .preview-title {
    font-size: var(--font-size-base);
  }
  
  .preview-button {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-xs);
  }
  
  .preview-button svg {
    width: 14px;
    height: 14px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-md);
  }
  
  .hero-title {
    font-size: var(--font-size-2xl);
  }
  
  .section-title {
    font-size: var(--font-size-3xl);
  }
  
  .service-card {
    padding: var(--spacing-lg);
  }
  
  .about-stats {
    grid-template-columns: 1fr;
  }
  
  /* Knowledge base preview mobile */
  .knowledge-base-preview {
    padding: var(--spacing-sm);
  }
  
  .preview-image {
    height: 120px;
  }
  
  .preview-title {
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-sm);
  }
  
  .preview-title::before {
    height: 16px;
    width: 3px;
  }
  
  .preview-description {
    font-size: var(--font-size-xs);
  }
}

/* Tablet specific adjustments */
@media (min-width: 769px) and (max-width: 1024px) {
  .preview-image {
    height: 180px;
  }
  
  .knowledge-base-preview {
    padding: var(--spacing-md);
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus styles for keyboard navigation */
.nav-link:focus,
.cta-button:focus,
.service-cta:focus,
.contact-link:focus,
.footer-link:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-border: #000000;
    --color-text-secondary: #000000;
  }
  
  [data-theme="dark"] {
    --color-border: #FFFFFF;
    --color-text-secondary: #FFFFFF;
  }
}