/* ============================================
   Adventure AI Academy - Main Styles
   Clean white background with gradient accents
   ============================================ */

/* CSS Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Brand Colors */
  --purple: #8b5cf6;
  --pink: #ec4899;
  --orange: #f97316;
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--purple) 0%, var(--pink) 50%, var(--orange) 100%);
  --gradient-overlay: linear-gradient(135deg, rgba(139, 92, 246, 0.9) 0%, rgba(236, 72, 153, 0.9) 50%, rgba(249, 115, 22, 0.9) 100%);
  
  /* Neutrals */
  --white: #ffffff;
  --black: #000000;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

body {
  font-family: var(--font-sans);
  background-color: var(--white);
  color: var(--gray-900);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-lg);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--spacing-md);
  color: var(--gray-600);
}

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

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

/* Container & Layout */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.container-wide {
  max-width: 1400px;
}

.container-narrow {
  max-width: 800px;
}

/* Navigation */
.navbar {
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  padding: var(--spacing-lg) 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.95);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  gap: var(--spacing-xl);
  list-style: none;
  align-items: center;
}

.nav-link {
  color: var(--gray-700);
  font-weight: 500;
  transition: color var(--transition-base);
}

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

.nav-link.active {
  color: var(--purple);
}

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--gray-700);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-lg);
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  border: none;
  transition: all var(--transition-base);
  font-size: 1rem;
  line-height: 1;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: var(--white);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--purple);
  color: var(--purple);
}

.btn-outline:hover {
  background: var(--purple);
  color: var(--white);
}

.btn-ghost {
  background: transparent;
  color: var(--gray-700);
}

.btn-ghost:hover {
  background: var(--gray-100);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.125rem;
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

/* Hero Section */
.hero {
  padding: var(--spacing-3xl) 0;
  text-align: center;
  background: linear-gradient(180deg, var(--white) 0%, var(--gray-50) 100%);
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: var(--spacing-lg);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.25rem;
  color: var(--gray-600);
  max-width: 600px;
  margin: 0 auto var(--spacing-2xl);
}

.hero-cta {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
}

/* Section */
.section {
  padding: var(--spacing-3xl) 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.section-subtitle {
  text-align: center;
  color: var(--gray-600);
  font-size: 1.125rem;
  max-width: 700px;
  margin: 0 auto var(--spacing-2xl);
}

/* Grid Layouts */
.grid {
  display: grid;
  gap: var(--spacing-xl);
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* Footer */
.footer {
  background: var(--gray-900);
  color: var(--gray-300);
  padding: var(--spacing-2xl) 0;
  margin-top: var(--spacing-3xl);
}

.footer-container {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.footer-brand {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--spacing-md);
}

.footer-desc {
  color: var(--gray-400);
  line-height: 1.6;
}

.footer-section h4 {
  color: var(--white);
  margin-bottom: var(--spacing-md);
  font-size: 1rem;
}

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

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

.footer-links a {
  color: var(--gray-400);
  transition: color var(--transition-base);
}

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

.footer-bottom {
  border-top: 1px solid var(--gray-800);
  padding-top: var(--spacing-lg);
  text-align: center;
  color: var(--gray-500);
}

/* Loading States */
.loading {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 200px;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--gray-200);
  border-top-color: var(--purple);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Error States */
.error {
  background: #fef2f2;
  color: #991b1b;
  padding: var(--spacing-lg);
  border-radius: var(--radius-md);
  border-left: 4px solid #dc2626;
}

/* Badge */
.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
}

.badge-beginner {
  background: #dbeafe;
  color: #1e40af;
}

.badge-intermediate {
  background: #fef3c7;
  color: #92400e;
}

.badge-advanced {
  background: #fee2e2;
  color: #991b1b;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-container { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  h1 { font-size: 2.25rem; }
  h2 { font-size: 1.875rem; }
  
  .hero h1 { font-size: 2.5rem; }
  .hero p { font-size: 1rem; }
  
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .footer-container {
    grid-template-columns: 1fr;
  }
  
  /* Mobile Navigation */
  .nav-menu {
    position: fixed;
    top: 73px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--gray-200);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    transition: all var(--transition-base);
    pointer-events: none;
  }
  
  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }
  
  .menu-toggle {
    display: block;
  }
  
  .hero-cta {
    flex-direction: column;
    align-items: center;
  }
  
  .hero-cta .btn {
    width: 100%;
    max-width: 300px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-md);
  }
  
  h1 { font-size: 1.875rem; }
  .hero h1 { font-size: 2rem; }
  
  .btn {
    width: 100%;
  }
}