/* Modern AI News Site - Medium/Mashable Inspired */

:root {
  --font-serif: 'Merriweather', Georgia, 'Times New Roman', serif;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  
  --color-bg: #ffffff;
  --color-bg-alt: #f7f7f7;
  --color-text: #292929;
  --color-text-muted: #757575;
  --color-text-light: #b3b3b3;
  --color-accent: #1a8917;
  --color-accent-hover: #0d6b0b;
  --color-border: #e6e6e6;
  --color-card: #ffffff;
  --color-nav: #ffffff;
  
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  
  --max-width: 1200px;
  --content-width: 680px;
  
  --transition: all 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

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

/* Typography */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.375rem; }

p {
  margin-bottom: 1.5rem;
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--color-text);
}

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

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

/* Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.content-wrapper {
  max-width: var(--content-width);
  margin: 0 auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.site-header nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.logo-icon {
  font-size: 1.5rem;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-muted);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero Section */
.hero {
  padding: 80px 0 60px;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 16px;
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 32px;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Section Headers */
.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 40px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}

.section-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
}

.view-all {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-accent);
}

.view-all:hover {
  text-decoration: underline;
}

/* Articles Grid */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 32px;
  margin-bottom: 80px;
}

.article-card {
  background: var(--color-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid var(--color-border);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

/* Category gradients for article cards */
.category-openai { background: linear-gradient(135deg, #10a37f 0%, #0d8c6d 100%); }
.category-google { background: linear-gradient(135deg, #4285f4 0%, #34a853 100%); }
.category-anthropic { background: linear-gradient(135deg, #d4a574 0%, #c49b6b 100%); }
.category-agents { background: linear-gradient(135deg, #7c3aed 0%, #db2777 100%); }
.category-regulation { background: linear-gradient(135deg, #dc2626 0%, #ea580c 100%); }
.category-enterprise { background: linear-gradient(135deg, #0891b2 0%, #0e7490 100%); }
.category-hardware { background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%); }
.category-startups { background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%); }
.category-default { background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%); }

.article-card-image {
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.article-card-image::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(180deg, transparent 0%, rgba(0,0,0,0.3) 100%);
}

.article-card-image .category-label {
  position: absolute;
  bottom: 16px;
  left: 16px;
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  z-index: 1;
}

.article-card-content {
  padding: 24px;
}

.article-card-category {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.article-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  line-height: 1.4;
}

.article-card-excerpt {
  font-size: 1rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: 16px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--color-text-light);
}

/* Categories Section */
.categories {
  padding: 60px 0;
  background: var(--color-bg-alt);
  margin: 60px 0;
}

.categories h2 {
  text-align: center;
  margin-bottom: 40px;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
}

.category-card {
  background: var(--color-card);
  padding: 32px 24px;
  border-radius: var(--radius-md);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid var(--color-border);
}

.category-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.category-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.category-name {
  font-size: 1.1rem;
  font-weight: 600;
}

/* Article Page */
.article-header {
  padding: 60px 0 40px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 40px;
}

.article-header h1 {
  font-size: 2.5rem;
  margin-bottom: 24px;
  line-height: 1.2;
}

.article-category {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.article-content {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  line-height: 1.8;
  color: var(--color-text);
}

.article-content h2 {
  font-family: var(--font-sans);
  font-size: 1.75rem;
  margin: 48px 0 24px;
  font-weight: 700;
}

.article-content h3 {
  font-family: var(--font-sans);
  font-size: 1.375rem;
  margin: 36px 0 18px;
}

.article-content p {
  margin-bottom: 32px;
}

.article-content ul,
.article-content ol {
  margin-bottom: 32px;
  padding-left: 32px;
}

.article-content li {
  margin-bottom: 12px;
}

.article-content strong {
  font-weight: 700;
}

.article-content a {
  color: var(--color-accent);
  text-decoration: underline;
}

.article-content blockquote {
  border-left: 4px solid var(--color-accent);
  padding-left: 24px;
  margin: 40px 0;
  font-style: italic;
  color: var(--color-text-muted);
}

/* Footer */
.site-footer {
  background: var(--color-bg-alt);
  padding: 60px 0 40px;
  border-top: 1px solid var(--color-border);
  margin-top: 80px;
}

.site-footer .container {
  text-align: center;
}

.site-footer p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-bottom: 8px;
}

.footer-links a {
  color: var(--color-text-muted);
  margin: 0 8px;
}

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

/* Mobile Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .mobile-menu-toggle {
    display: block;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .articles-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .article-header h1 {
    font-size: 1.75rem;
  }
  
  .article-content {
    font-size: 1.125rem;
  }
  
  .category-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}