/* Modern CSS Framework for Endless */
/* Based on popular design patterns from Stripe, Linear, Vercel, etc. */

:root {
  /* Modern Color Palette */
  --bg-primary: #ffffff;
  --bg-secondary: #fafafa;
  --bg-tertiary: #f5f5f5;
  --bg-accent: #f8fafc;
  --text-primary: #1a1a1a;
  --text-secondary: #666666;
  --text-muted: #8a8a8a;
  --border-primary: #e5e5e5;
  --border-secondary: #f0f0f0;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --brand-primary: #0066cc;
  --brand-hover: #0052a3;
  --brand-light: #e6f2ff;
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Roboto Mono', monospace;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-tertiary: #1a1a1a;
  --bg-accent: #141414;
  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --text-muted: #6a6a6a;
  --border-primary: #2a2a2a;
  --border-secondary: #1f1f1f;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.5);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4), 0 2px 4px -2px rgb(0 0 0 / 0.4);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.2), 0 8px 10px -6px rgb(0 0 0 / 0.2);
  --brand-light: #001a33;
}

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

html {
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: var(--transition);
}

/* Modern Typography */
.text-xs { font-size: 12px; line-height: 16px; }
.text-sm { font-size: 14px; line-height: 20px; }
.text-base { font-size: 16px; line-height: 24px; }
.text-lg { font-size: 18px; line-height: 28px; }
.text-xl { font-size: 20px; line-height: 28px; }
.text-2xl { font-size: 24px; line-height: 32px; }
.text-3xl { font-size: 30px; line-height: 36px; }
.text-4xl { font-size: 36px; line-height: 40px; }
.text-5xl { font-size: 48px; line-height: 1; }
.text-6xl { font-size: 60px; line-height: 1; }

.font-light { font-weight: 300; }
.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }

/* Modern Layout Utilities */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-sm { max-width: 640px; }
.container-md { max-width: 768px; }
.container-lg { max-width: 1024px; }
.container-xl { max-width: 1200px; }

.section {
  padding: 80px 0;
}

.section-sm { padding: 48px 0; }
.section-lg { padding: 120px 0; }

/* Flexbox Utilities */
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.items-end { align-items: flex-end; }
.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.flex-wrap { flex-wrap: wrap; }
.flex-1 { flex: 1; }
.gap-1 { gap: 4px; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }
.gap-6 { gap: 24px; }
.gap-8 { gap: 32px; }
.gap-12 { gap: 48px; }

/* Grid Utilities */
.grid { display: grid; }
.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
.col-span-2 { grid-column: span 2; }
.col-span-3 { grid-column: span 3; }

/* Modern Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  font-family: inherit;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

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

.btn-primary:hover {
  background-color: var(--brand-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-primary);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--border-primary);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn-outline {
  background-color: transparent;
  color: var(--brand-primary);
  border: 1px solid var(--brand-primary);
}

.btn-outline:hover {
  background-color: var(--brand-light);
  transform: translateY(-1px);
}

.btn-lg {
  padding: 16px 32px;
  font-size: 16px;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 12px;
}

/* Modern Cards */
.card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

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

.card-header {
  margin-bottom: 16px;
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.card-description {
  color: var(--text-secondary);
  font-size: 14px;
}

/* Modern Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-secondary);
  padding: 16px 0;
}

[data-theme="dark"] .nav {
  background-color: rgba(10, 10, 10, 0.8);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

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

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 14px;
  transition: var(--transition);
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* Hero Section */
.hero {
  padding: 120px 0 80px;
  text-align: center;
  background: linear-gradient(
    135deg,
    var(--bg-primary) 0%,
    var(--bg-accent) 100%
  );
}

.hero-title {
  font-size: clamp(36px, 5vw, 60px);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 24px;
  background: linear-gradient(
    135deg,
    var(--text-primary) 0%,
    var(--text-secondary) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  font-size: 20px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 40px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

/* Feature Grid */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
  margin: 60px 0;
}

.feature {
  text-align: center;
  padding: 32px 24px;
}

.feature-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  background-color: var(--brand-light);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.feature-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
}

.feature-description {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Stats Section */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  text-align: center;
}

.stat {
  padding: 24px;
}

.stat-number {
  font-size: 48px;
  font-weight: 700;
  color: var(--brand-primary);
  display: block;
  line-height: 1;
  margin-bottom: 8px;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}

/* Modern Footer */
.footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-primary);
  padding: 60px 0 40px;
  margin-top: 120px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 16px;
}

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

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  transition: var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-primary);
  padding-top: 24px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 14px;
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }
  
  .section {
    padding: 60px 0;
  }
  
  .hero {
    padding: 80px 0 60px;
  }
  
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    max-width: 280px;
  }
  
  .nav-links {
    display: none;
  }
  
  .features {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out;
}

.animate-delay-100 { animation-delay: 100ms; }
.animate-delay-200 { animation-delay: 200ms; }
.animate-delay-300 { animation-delay: 300ms; }

/* Loading States */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

.skeleton {
  background: linear-gradient(90deg, var(--bg-tertiary) 25%, var(--bg-secondary) 50%, var(--bg-tertiary) 75%);
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
}

@keyframes skeleton-loading {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}