/* =============================
   AI Tools Hub v3 - Global CSS
   Dark Theme: #0a0a0f + #6366f1 accent
   ============================= */

/* === RESET & BASE === */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: #16161f;
  --border: #2a2a3a;
  --accent: #6366f1;
  --accent-hover: #818cf8;
  --text-primary: #e0e0e0;
  --text-secondary: #888;
  --text-muted: #555;
  --success: #22c55e;
  --warning: #eab308;
  --danger: #ef4444;
  --radius: 8px;
  --container: 1200px;
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover { color: var(--accent-hover); }

img { max-width: 100%; height: auto; }

/* === LAYOUT === */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

/* === NAVIGATION === */
.site-nav {
  border-bottom: 1px solid var(--border);
  padding: 15px 0;
  position: sticky;
  top: 0;
  background: rgba(10, 10, 15, 0.95);
  backdrop-filter: blur(10px);
  z-index: 100;
}

.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

.site-logo {
  color: var(--accent);
  font-size: 1.3rem;
  font-weight: 700;
  text-decoration: none;
}
.site-logo:hover { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  text-decoration: none;
  transition: color 0.2s;
}
.nav-links a:hover,
.nav-links a[aria-current="page"] { color: var(--accent); }

/* === HERO === */
.hero {
  text-align: center;
  padding: 60px 20px 40px;
}
.hero h1 {
  font-size: 2.2rem;
  margin-bottom: 12px;
  color: var(--text-primary);
  line-height: 1.3;
}
.hero .subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
}

/* === SECTIONS === */
.section { padding: 40px 0; }

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.section-title {
  font-size: 1.4rem;
  color: var(--text-primary);
  position: relative;
  padding-left: 16px;
}
.section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 24px;
  background: var(--accent);
  border-radius: 2px;
}

.section-more { color: var(--text-secondary); font-size: 0.9rem; }
.section-more:hover { color: var(--accent); }

/* === CARDS === */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color 0.2s, transform 0.2s;
}
.card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.card-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--accent);
  margin-bottom: 8px;
}

.card h3 { font-size: 1.1rem; margin-bottom: 8px; line-height: 1.4; }
.card h3 a { color: var(--text-primary); }
.card h3 a:hover { color: var(--accent); }
.card p { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.6; }
.card-meta { margin-top: 12px; font-size: 0.8rem; color: var(--text-muted); }

/* === FACT CARD === */
.fact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 30px;
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
}
.fact-card .fact-number {
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 12px;
}
.fact-card h2 { font-size: 1.2rem; margin-bottom: 12px; }
.fact-card p { color: var(--text-secondary); font-size: 0.95rem; }

/* === TOOLS GRID === */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.tool-card h3 { font-size: 1rem; }
.tool-card h3 a { color: var(--text-primary); }
.tool-card h3 a:hover { color: var(--accent); }
.tool-card p { color: var(--text-secondary); font-size: 0.85rem; flex-grow: 1; }

.tool-badges { display: flex; gap: 8px; flex-wrap: wrap; }

.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 500;
}
.badge-freemium { background: rgba(99,102,241,0.15); color: var(--accent); }
.badge-free { background: rgba(34,197,94,0.15); color: var(--success); }
.badge-paid { background: rgba(239,68,68,0.15); color: var(--danger); }

/* === BREADCRUMB === */
.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.breadcrumb a { color: var(--text-secondary); }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb span { color: var(--text-muted); margin: 0 6px; }

/* === ARTICLE === */
.article-content { max-width: 720px; margin: 0 auto; }
.article-content h1 { font-size: 1.8rem; margin-bottom: 8px; line-height: 1.3; }
.article-content h2 {
  font-size: 1.3rem;
  margin: 32px 0 12px;
  padding-left: 12px;
  border-left: 3px solid var(--accent);
}
.article-content p { margin-bottom: 16px; color: var(--text-secondary); }
.article-content ul, .article-content ol {
  margin: 12px 0 16px 24px;
  color: var(--text-secondary);
}
.article-content li { margin-bottom: 6px; }
.article-content strong { color: var(--text-primary); }

.article-meta {
  display: flex;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* === CONFIDENCE BADGES === */
.confidence-high {
  background: rgba(34,197,94,0.15);
  color: var(--success);
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
}
.confidence-medium {
  background: rgba(234,179,8,0.15);
  color: var(--warning);
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
}
.confidence-low {
  background: rgba(239,68,68,0.15);
  color: var(--danger);
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
}

/* === FOOTER === */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  margin-top: 60px;
}
.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
}
.footer-col h4 { color: var(--text-primary); font-size: 0.95rem; margin-bottom: 12px; }
.footer-col a { display: block; color: var(--text-secondary); font-size: 0.85rem; margin-bottom: 6px; }
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
  text-align: center;
  padding-top: 24px;
  margin-top: 24px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* === RESPONSIVE === */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.6rem; }
  .card-grid { grid-template-columns: 1fr; }
  .tools-grid { grid-template-columns: 1fr 1fr; }
  .nav-links { gap: 16px; }
  .section-title { font-size: 1.2rem; }
}
@media (max-width: 480px) {
  .tools-grid { grid-template-columns: 1fr; }
}

/* === TABLES === */
.table-responsive { overflow-x: auto; margin: 16px 0; }
table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
th, td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--border); }
th { color: var(--text-primary); font-weight: 600; background: var(--bg-secondary); }
td { color: var(--text-secondary); }