/* AI Blog Theme - Modern CSS */

/* CSS Variables */
:root {
  /* Colors */
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --secondary: #64748b;
  --accent: #8b5cf6;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  
  /* Light Theme */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #e2e8f0;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  
  /* Dark Theme */
  --dark-bg-primary: #0f172a;
  --dark-bg-secondary: #1e293b;
  --dark-bg-tertiary: #334155;
  --dark-text-primary: #f1f5f9;
  --dark-text-secondary: #cbd5e1;
  --dark-text-muted: #64748b;
  --dark-border: #334155;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'Fira Code', 'Monaco', 'Consolas', monospace;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* 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);
}

/* Dark Mode */
[data-theme="dark"] {
  --bg-primary: var(--dark-bg-primary);
  --bg-secondary: var(--dark-bg-secondary);
  --bg-tertiary: var(--dark-bg-tertiary);
  --text-primary: var(--dark-text-primary);
  --text-secondary: var(--dark-text-secondary);
  --text-muted: var(--dark-text-muted);
  --border: var(--dark-border);
}

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

body {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: all 0.3s ease;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

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

/* Header */
.header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) 0;
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: var(--spacing-xl);
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  transition: color 0.3s ease;
}

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

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: white;
  padding: var(--spacing-2xl) 0;
  text-align: center;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: white;
}

.hero-description {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-xl);
  color: rgba(255, 255, 255, 0.9);
}

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  padding: var(--spacing-md) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-md);
  font-weight: 600;
  text-decoration: none;
  transition: all 0.3s ease;
  cursor: pointer;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: transparent;
  color: white;
  border: 2px solid white;
}

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

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

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

/* Cards */
.category-card,
.article-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all 0.3s ease;
  text-decoration: none;
  color: inherit;
}

.category-card:hover,
.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary);
}

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

.category-card p {
  color: var(--text-muted);
  margin-bottom: 0;
}

/* Grids */
.categories-grid,
.articles-grid {
  display: grid;
  gap: var(--spacing-lg);
}

.categories-grid {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.articles-grid {
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
}

/* Article Cards */
.article-image {
  width: 100%;
  height: 200px;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: var(--spacing-md);
}

.article-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.article-card:hover .article-image img {
  transform: scale(1.05);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.article-category {
  background: var(--primary);
  color: white;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
}

.article-date {
  color: var(--text-muted);
  font-size: 0.875rem;
}

.article-title {
  margin-bottom: var(--spacing-sm);
}

.article-title a {
  color: var(--text-primary);
  text-decoration: none;
}

.article-title a:hover {
  color: var(--primary);
}

.article-excerpt {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
}

.article-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.tag {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 500;
}

/* Sections */
.section-title {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.categories-section,
.articles-section,
.stats-section {
  padding: var(--spacing-2xl) 0;
}

.stats-section {
  background: var(--bg-secondary);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-xl);
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: var(--spacing-xs);
}

.stat-label {
  color: var(--text-secondary);
  font-weight: 500;
}

.view-all-container {
  text-align: center;
  margin-top: var(--spacing-2xl);
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: var(--spacing-2xl) 0;
  margin-top: var(--spacing-2xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

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

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

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

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

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

/* Responsive Design */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .nav-list {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-actions {
    flex-direction: column;
  }
  
  .categories-grid,
  .articles-grid {
    grid-template-columns: 1fr;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
}

/* Utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-4 { margin-top: var(--spacing-md); }
.mt-6 { margin-top: var(--spacing-lg); }
.mt-8 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-4 { margin-bottom: var(--spacing-md); }
.mb-6 { margin-bottom: var(--spacing-lg); }
.mb-8 { margin-bottom: var(--spacing-xl); }

.p-4 { padding: var(--spacing-md); }
.p-6 { padding: var(--spacing-lg); }
.p-8 { padding: var(--spacing-xl); }