/* ============================================
   BLOG STYLES - Polished UI Design
   ============================================ */

/* Import Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Merriweather:wght@300;400;700&display=swap');

/* ============================================
   ROOT VARIABLES
   ============================================ */
:root {
  /* Colors */
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #7c3aed;
  --accent-color: #f59e0b;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --text-light: #9ca3af;
  --background: #ffffff;
  --background-alt: #f9fafb;
  --border-color: #e5e7eb;
  --card-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Merriweather', Georgia, serif;
  
  /* Spacing */
  --container-max-width: 1200px;
  --content-max-width: 800px;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
}

/* ============================================
   BLOG CONTAINER
   ============================================ */
.blog-container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-md);
  font-family: var(--font-sans);
  color: var(--text-primary);
  background-color: var(--background);
}

/* ============================================
   BLOG HEADER
   ============================================ */
.blog-header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 2px solid var(--border-color);
}

.blog-header h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.blog-header p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================
   CATEGORY FILTERS
   ============================================ */
.category-filters {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: var(--spacing-xl);
}

.category-filter-btn {
  padding: var(--spacing-xs) var(--spacing-md);
  border: 2px solid var(--border-color);
  background: var(--background);
  color: var(--text-secondary);
  border-radius: var(--radius-lg);
  font-weight: 500;
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.category-filter-btn:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
  background: rgba(37, 99, 235, 0.05);
}

.category-filter-btn.active {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

/* ============================================
   BLOG GRID
   ============================================ */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-2xl);
}

/* ============================================
   BLOG CARD
   ============================================ */
.blog-card {
  background: var(--background);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--card-shadow);
  cursor: pointer;
  display: flex;
  flex-direction: column;
}

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

.blog-card-header {
  padding: var(--spacing-md) var(--spacing-md) 0;
}

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

.blog-card-category {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.blog-card-date {
  color: var(--text-light);
  font-size: 0.875rem;
}

.blog-card-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
  line-height: 1.3;
}

.blog-card-excerpt {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
  margin-bottom: var(--spacing-md);
}

.blog-card-footer {
  padding: 0 var(--spacing-md) var(--spacing-md);
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.blog-card-read-time {
  color: var(--text-light);
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.blog-card-read-time::before {
  content: "📖";
}

.read-more-btn {
  color: var(--primary-color);
  font-weight: 600;
  font-size: 0.875rem;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  transition: gap 0.2s ease;
}

.read-more-btn:hover {
  gap: 0.5rem;
}

.read-more-btn::after {
  content: "→";
}

/* ============================================
   BLOG POST (FULL ARTICLE VIEW)
   ============================================ */
.blog-post {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: var(--spacing-xl) var(--spacing-md);
}

.blog-post-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
}

.blog-post-category {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: var(--spacing-md);
}

.blog-post-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  line-height: 1.2;
  color: var(--text-primary);
}

.blog-post-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.blog-post-meta span {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* ============================================
   BLOG CONTENT
   ============================================ */
.blog-content {
  font-family: var(--font-serif);
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.blog-content p {
  margin-bottom: var(--spacing-md);
}

.blog-content h2 {
  font-family: var(--font-sans);
  font-size: 2rem;
  font-weight: 700;
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
  position: relative;
  padding-bottom: var(--spacing-sm);
}

.blog-content h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  border-radius: 2px;
}

.blog-content h3 {
  font-family: var(--font-sans);
  font-size: 1.5rem;
  font-weight: 600;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.blog-content ul,
.blog-content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-xl);
}

.blog-content li {
  margin-bottom: var(--spacing-xs);
  line-height: 1.7;
}

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

.blog-content a {
  color: var(--primary-color);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}

.blog-content a:hover {
  border-bottom-color: var(--primary-color);
}

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

.blog-content em {
  font-style: italic;
}

/* ============================================
   SOURCES SECTION
   ============================================ */
.blog-content h3:has(+ ul) {
  margin-top: var(--spacing-2xl);
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
}

.blog-content h3 + ul a {
  word-break: break-word;
}

/* ============================================
   BACK BUTTON
   ============================================ */
.back-to-blog {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9375rem;
  margin-bottom: var(--spacing-lg);
  transition: gap 0.2s ease;
}

.back-to-blog:hover {
  gap: 0.75rem;
}

.back-to-blog::before {
  content: "←";
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
  .blog-header h1 {
    font-size: 2rem;
  }
  
  .blog-header p {
    font-size: 1rem;
  }
  
  .blog-grid {
    grid-template-columns: 1fr;
  }
  
  .blog-post-title {
    font-size: 1.875rem;
  }
  
  .blog-content {
    font-size: 1rem;
  }
  
  .blog-content h2 {
    font-size: 1.5rem;
  }
  
  .blog-content h3 {
    font-size: 1.25rem;
  }
}

/* ============================================
   DARK MODE SUPPORT (Optional)
   ============================================ */

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-center {
  text-align: center;
}

.mt-xl {
  margin-top: var(--spacing-xl);
}

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

/* ============================================
   LOADING STATES & ANIMATIONS
   ============================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.blog-card {
  animation: fadeIn 0.5s ease-out;
}

.blog-card:nth-child(1) { animation-delay: 0.1s; }
.blog-card:nth-child(2) { animation-delay: 0.2s; }
.blog-card:nth-child(3) { animation-delay: 0.3s; }
.blog-card:nth-child(4) { animation-delay: 0.4s; }
.blog-card:nth-child(5) { animation-delay: 0.5s; }
.blog-card:nth-child(6) { animation-delay: 0.6s; }
.blog-card:nth-child(7) { animation-delay: 0.7s; }
.blog-card:nth-child(8) { animation-delay: 0.8s; }