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

:root {
  --bg: #0a0a0f;
  --bg-card: rgba(255,255,255,0.035);
  --bg-card-hover: rgba(255,255,255,0.06);
  --border: rgba(255,255,255,0.08);
  --border-hover: rgba(255,255,255,0.15);
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --primary: #6366f1;
  --primary-light: #8b5cf6;
  --primary-glow: rgba(99, 102, 241, 0.15);
  --accent-green: #10b981;
  --accent-orange: #f59e0b;
  --accent-blue: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-pink: #ec4899;
  --gradient-hero: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
  --max-w: 1200px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ============ ANIMATED BACKGROUND ============ */
.bg-grid {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
}

.bg-glow {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.bg-glow::before {
  content: '';
  position: absolute;
  top: -30%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 600px;
  background: radial-gradient(ellipse at center, rgba(99, 102, 241, 0.08) 0%, transparent 70%);
  animation: pulse-glow 8s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% { opacity: 0.5; transform: translateX(-50%) scale(1); }
  50% { opacity: 1; transform: translateX(-50%) scale(1.1); }
}

/* ============ LAYOUT ============ */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* ============ HEADER / NAV ============ */
header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(10, 10, 15, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--gradient-hero);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.9rem;
  color: white;
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}

.nav-links a {
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s;
}

.nav-links a:hover {
  color: var(--text);
  background: var(--bg-card);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  cursor: pointer;
  padding: 0.5rem;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: rgba(10, 10, 15, 0.98);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem;
    gap: 0.25rem;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    width: 100%;
    padding: 0.75rem 1rem;
  }

  .mobile-menu-btn {
    display: block;
  }
}

/* ============ HERO ============ */
.hero {
  padding: 6rem 0 4rem;
  text-align: center;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.375rem 1rem;
  border-radius: 9999px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
  transition: all 0.2s;
}

.hero-badge:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
}

.hero-badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-green);
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-md);
  background: var(--gradient-hero);
  color: white;
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  transition: all 0.3s;
  border: none;
  cursor: pointer;
  box-shadow: 0 0 30px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 50px var(--primary-glow);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-md);
  background: var(--bg-card);
  color: var(--text);
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  border: 1px solid var(--border);
  transition: all 0.3s;
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 4rem;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.8125rem;
  color: var(--text-dim);
  margin-top: 0.125rem;
}

/* ============ SECTION COMMON ============ */
section {
  padding: 5rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--primary-light);
  margin-bottom: 0.75rem;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1.0625rem;
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ============ FEATURES / LIBRARIES ============ */
.libraries-section {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.libraries-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}

.library-card {
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: all 0.3s;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.library-card:hover {
  border-color: rgba(99, 102, 241, 0.3);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.08);
}

.library-card-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.library-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.85rem;
  color: white;
  flex-shrink: 0;
}

.library-name {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}

.library-badge {
  font-size: 0.6875rem;
  padding: 0.125rem 0.5rem;
  border-radius: 9999px;
  background: rgba(99, 102, 241, 0.15);
  color: var(--primary-light);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-left: auto;
}

.library-badge.beta { background: rgba(245, 158, 11, 0.15); color: var(--accent-orange); }
.library-badge.alpha { background: rgba(236, 72, 153, 0.15); color: var(--accent-pink); }
.library-badge.new { background: rgba(16, 185, 129, 0.15); color: var(--accent-green); }

.library-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.library-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  margin-top: auto;
}

.library-tag {
  font-size: 0.6875rem;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  background: rgba(255,255,255,0.05);
  color: var(--text-dim);
}

/* ============ TRUSTED BY ============ */
.trusted-section {
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.trusted-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-dim);
  margin-bottom: 2rem;
}

.trusted-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2.5rem;
  flex-wrap: wrap;
}

.trusted-logo {
  padding: 0 0.5rem;
  opacity: 0.5;
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text-muted);
  transition: opacity 0.3s;
  white-space: nowrap;
}

.trusted-logo:hover {
  opacity: 0.8;
}

/* ============ WHY TANSTACK ============ */
.why-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.why-card {
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: all 0.3s;
}

.why-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

.why-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  font-size: 1.25rem;
}

.why-card h3 {
  font-size: 1.0625rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.why-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ============ BRIDGE / CTA ============ */
.bridge-section {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 6rem 0;
}

.bridge-title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.bridge-desc {
  color: var(--text-muted);
  font-size: 1.0625rem;
  max-width: 520px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

/* ============ FOOTER ============ */
footer {
  border-top: 1px solid var(--border);
  padding: 3rem 0;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-copy {
  font-size: 0.8125rem;
  color: var(--text-dim);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.footer-links a {
  font-size: 0.8125rem;
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
}

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

.footer-social {
  display: flex;
  gap: 1rem;
}

.footer-social a {
  color: var(--text-dim);
  transition: color 0.2s;
  display: flex;
  align-items: center;
}

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

/* ============ RESPONSIVE ============ */
@media (max-width: 768px) {
  .hero { padding: 4rem 0 2.5rem; }
  .hero-stats { gap: 2rem; }
  .libraries-grid { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; text-align: center; }
}

/* ============ UTILITIES ============ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}