:root {
  /* Primary Colors */
  --primary: #1E40AF;
  --primary-light: #3B82F6;
  --primary-dark: #1e3a8a;
  
  /* Secondary Colors */
  --accent: #0EA5E9;
  --accent-light: #38BDF8;
  
  /* Neutral Colors */
  --text-primary: #1F2937;
  --text-secondary: #6B7280;
  --text-light: #9CA3AF;
  --bg-primary: #FFFFFF;
  --bg-secondary: #F9FAFB;
  --bg-tertiary: #F3F4F6;
  --border-color: #E5E7EB;
  
  /* Success, Warning, Error */
  --success: #10B981;
  --warning: #F59E0B;
  --error: #EF4444;
  
  /* Shadows */
  --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);
  
  /* Spacing */
  --spacing-unit: 8px;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'Monaco', 'Courier New', monospace;
}

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

html {
  scroll-behavior: smooth;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: 2rem;
  margin-top: 2rem;
  margin-bottom: 1.2rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary);
}

h3 {
  font-size: 1.5rem;
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
}

h4 {
  font-size: 1.25rem;
}

h5 {
  font-size: 1.1rem;
}

h6 {
  font-size: 1rem;
}

p {
  margin-bottom: 1rem;
  line-height: 1.8;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

strong {
  font-weight: 600;
}

em {
  font-style: italic;
}

/* Lists */
ul, ol {
  margin-left: 2rem;
  margin-bottom: 1rem;
}

li {
  margin-bottom: 0.5rem;
  line-height: 1.8;
}

/* Code */
code {
  background-color: var(--bg-tertiary);
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

pre {
  background-color: #1F2937;
  color: #E5E7EB;
  padding: 1.5rem;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-bottom: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.5;
}

pre code {
  background: none;
  padding: 0;
  color: inherit;
}

/* Blockquotes */
blockquote {
  border-left: 4px solid var(--primary);
  padding-left: 1.5rem;
  margin-left: 0;
  margin-bottom: 1.5rem;
  color: var(--text-secondary);
  font-style: italic;
}

/* Header */
header {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.logo img {
  width: 40px;
  height: 40px;
}

.logo span {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-top: -0.25rem;
}

/* Navigation */
nav {
  display: flex;
  gap: 2rem;
}

nav a {
  color: var(--text-primary);
  font-weight: 500;
  position: relative;
  transition: color 0.3s ease;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary);
  transition: width 0.3s ease;
}

nav a:hover::after {
  width: 100%;
}

/* Footer */
footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 3rem 2rem;
  margin-top: 4rem;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h4 {
  margin-bottom: 1rem;
  color: var(--primary);
}

.footer-section ul {
  list-style: none;
  margin-left: 0;
}

.footer-section ul li {
  margin-bottom: 0.5rem;
}

.footer-section a {
  color: var(--text-secondary);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
  text-align: center;
  color: var(--text-light);
  font-size: 0.9rem;
}

.footer-bottom p {
  margin: 0;
}

/* Main Content */
main {
  max-width: 900px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

.article {
  background-color: var(--bg-primary);
}

.article-meta {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 2rem;
  display: flex;
  gap: 1.5rem;
}

.article-meta span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Containers & Cards */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

/* Highlights & Callouts */
.highlight {
  background-color: #FEF3C7;
  border-left: 4px solid var(--warning);
  padding: 1rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.5rem;
}

.info-box {
  background-color: #DBEAFE;
  border-left: 4px solid var(--primary);
  padding: 1rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.5rem;
}

.success-box {
  background-color: #DCFCE7;
  border-left: 4px solid var(--success);
  padding: 1rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.5rem;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background-color: var(--primary);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  text-align: center;
}

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

.btn-secondary {
  background-color: var(--accent);
}

.btn-secondary:hover {
  background-color: var(--accent-light);
}

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}

.btn-outline:hover {
  background-color: var(--primary);
  color: white;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

th {
  background-color: var(--primary);
  color: white;
  padding: 1rem;
  text-align: left;
  font-weight: 600;
}

td {
  padding: 1rem;
  border-top: 1px solid var(--border-color);
}

tr:nth-child(even) {
  background-color: var(--bg-secondary);
}

/* Interactive Elements */
.accordion {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 1.5rem;
}

.accordion-item {
  border-bottom: 1px solid var(--border-color);
}

.accordion-item:last-child {
  border-bottom: none;
}

.accordion-header {
  background-color: var(--bg-secondary);
  padding: 1rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  transition: background-color 0.3s ease;
}

.accordion-header:hover {
  background-color: var(--bg-tertiary);
}

.accordion-content {
  padding: 1rem;
  display: none;
}

.accordion-content.active {
  display: block;
}

.accordion-icon {
  transition: transform 0.3s ease;
}

.accordion-icon.active {
  transform: rotate(180deg);
}

/* Partner Block */
.partner-block {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: white;
  padding: 3rem;
  border-radius: var(--radius-xl);
  text-align: center;
  margin-top: 4rem;
  box-shadow: var(--shadow-lg);
}

.partner-block h3 {
  color: white;
  border-bottom: none;
  margin-top: 0;
}

.partner-block p {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
}

.partner-link {
  display: inline-block;
  background-color: white;
  color: var(--primary);
  padding: 1rem 2rem;
  border-radius: var(--radius-lg);
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s ease;
}

.partner-link:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl);
}

/* Responsive */
@media (max-width: 768px) {
  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  h3 {
    font-size: 1.25rem;
  }

  .header-container {
    flex-direction: column;
    gap: 1rem;
  }

  nav {
    gap: 1rem;
    flex-wrap: wrap;
  }

  main {
    padding: 1.5rem 1rem;
  }

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

  .article-meta {
    flex-direction: column;
    gap: 0.5rem;
  }

  .partner-block {
    padding: 2rem;
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.5rem;
  }

  h2 {
    font-size: 1.25rem;
  }

  nav {
    gap: 0.5rem;
  }

  .btn {
    display: block;
    width: 100%;
  }

  table {
    font-size: 0.9rem;
  }

  th, td {
    padding: 0.75rem;
  }
}

/* Utility Classes */
.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

.mt-1 { margin-top: calc(var(--spacing-unit) * 1); }
.mt-2 { margin-top: calc(var(--spacing-unit) * 2); }
.mt-3 { margin-top: calc(var(--spacing-unit) * 3); }
.mt-4 { margin-top: calc(var(--spacing-unit) * 4); }

.mb-1 { margin-bottom: calc(var(--spacing-unit) * 1); }
.mb-2 { margin-bottom: calc(var(--spacing-unit) * 2); }
.mb-3 { margin-bottom: calc(var(--spacing-unit) * 3); }
.mb-4 { margin-bottom: calc(var(--spacing-unit) * 4); }

.p-1 { padding: calc(var(--spacing-unit) * 1); }
.p-2 { padding: calc(var(--spacing-unit) * 2); }
.p-3 { padding: calc(var(--spacing-unit) * 3); }
.p-4 { padding: calc(var(--spacing-unit) * 4); }

.flex { display: flex; }
.gap-1 { gap: calc(var(--spacing-unit) * 1); }
.gap-2 { gap: calc(var(--spacing-unit) * 2); }
.gap-3 { gap: calc(var(--spacing-unit) * 3); }

.hidden { display: none; }
.visible { display: block; }