/* ============================================
   VTECH-HUB 2026 — COMPLETE DESIGN SYSTEM
   Modern, Dark, Gamified, Conversion-Optimized
   ============================================ */

/* CSS Variables — Theme Tokens */
:root {
  /* Colors — Primary (Indigo/Blue) */
  --primary-50: #EEF2FF;
  --primary-100: #E0E7FF;
  --primary-500: #6366F1;
  --primary-600: #4F46E5;
  --primary-700: #4338CA;
  --primary-900: #312E81;
  
  /* Colors — Secondary (Emerald/Green) */
  --secondary-400: #34D399;
  --secondary-500: #10B981;
  --secondary-600: #059669;
  --secondary-900: #064E3B;
  
  /* Colors — Accent (Amber/Orange) */
  --accent-400: #FBBF24;
  --accent-500: #F59E0B;
  --accent-600: #D97706;
  
  /* Colors — Gamification */
  --bronze: #CD7F32;
  --silver: #C0C0C0;
  --gold: #FFD700;
  --platinum: #E5E4E2;
  --diamond: #B9F2FF;
  
  /* Backgrounds — Dark Theme */
  --bg-page: #0F172A;
  --bg-card: #1E293B;
  --bg-elevated: #334155;
  --bg-hover: #475569;
  
  /* Text */
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  
  /* Semantic */
  --success: #10B981;
  --warning: #F59E0B;
  --error: #EF4444;
  --info: #3B82F6;
  
  /* Spacing Scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* 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);
  --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
}

/* ============================================
   BASE STYLES
   ============================================ */

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.6;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 var(--space-4) 0;
}

h1 {
  font-size: var(--text-5xl);
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--primary-500) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

h2 {
  font-size: var(--text-3xl);
  color: var(--text-primary);
}

h3 {
  font-size: var(--text-2xl);
  color: var(--text-primary);
}

p {
  margin: 0 0 var(--space-4) 0;
  color: var(--text-secondary);
}

a {
  color: var(--primary-500);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-400);
}

/* ============================================
   LAYOUT — Container & Grid
   ============================================ */

.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

@media (min-width: 640px) {
  .container {
    padding: 0 var(--space-6);
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--space-8);
  }
}

.grid {
  display: grid;
  gap: var(--space-6);
}

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

@media (min-width: 768px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

@media (min-width: 768px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.gap-4 {
  gap: var(--space-4);
}

.gap-6 {
  gap: var(--space-6);
}

/* ============================================
   CARDS — Content Cards
   ============================================ */

.card {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: transform var(--transition-base), 
              box-shadow var(--transition-base),
              border-color var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl), var(--shadow-glow);
  border-color: var(--primary-500);
}

.card-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.card-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xl);
}

.card-title {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.card-body {
  color: var(--text-secondary);
}

/* ============================================
   BUTTONS — CTA Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-base);
  font-weight: 600;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-700), var(--primary-600));
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  color: white;
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
  background: var(--bg-hover);
  border-color: var(--primary-500);
  color: var(--text-primary);
}

.btn-glow {
  position: relative;
  overflow: hidden;
}

.btn-glow::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s;
}

.btn-glow:hover::before {
  left: 100%;
}

/* ============================================
   GAMIFICATION — Points, Badges, Levels
   ============================================ */

.gamification-bar {
  background: var(--bg-elevated);
  border-radius: var(--radius-full);
  padding: var(--space-2) var(--space-4);
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-sm);
  font-weight: 600;
}

.points-display {
  color: var(--accent-500);
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.points-display::before {
  content: '★';
  color: var(--gold);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-bronze {
  background: rgba(205, 127, 50, 0.2);
  color: var(--bronze);
  border: 1px solid var(--bronze);
}

.badge-silver {
  background: rgba(192, 192, 192, 0.2);
  color: var(--silver);
  border: 1px solid var(--silver);
}

.badge-gold {
  background: rgba(255, 215, 0, 0.2);
  color: var(--gold);
  border: 1px solid var(--gold);
}

.badge-platinum {
  background: rgba(229, 228, 226, 0.2);
  color: var(--platinum);
  border: 1px solid var(--platinum);
}

.level-indicator {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: linear-gradient(135deg, var(--primary-900), var(--primary-700));
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  font-weight: 600;
}

.level-number {
  color: var(--accent-500);
}

/* Progress Bar */
.progress-container {
  background: var(--bg-elevated);
  border-radius: var(--radius-full);
  height: 8px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-600), var(--secondary-500));
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
  position: relative;
}

.progress-bar::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* ============================================
   NAVIGATION — Header & Menu
   ============================================ */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.navbar-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.navbar-brand {
  font-size: var(--text-xl);
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary-500), var(--secondary-500));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.navbar-nav {
  display: none;
  gap: var(--space-6);
}

@media (min-width: 768px) {
  .navbar-nav {
    display: flex;
  }
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-500);
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
  padding-top: 140px;
  padding-bottom: var(--space-16);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--primary-500) 0%, transparent 70%);
  opacity: 0.1;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--space-6);
}

.hero-subtitle {
  font-size: var(--text-xl);
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto var(--space-8);
}

.hero-cta {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  align-items: center;
}

@media (min-width: 640px) {
  .hero-cta {
    flex-direction: row;
    justify-content: center;
  }
}

/* Stats Row */
.stats-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-12);
}

@media (min-width: 640px) {
  .stats-row {
    grid-template-columns: repeat(4, 1fr);
  }
}

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

.stat-number {
  font-size: var(--text-3xl);
  font-weight: 800;
  color: var(--primary-500);
  display: block;
}

.stat-label {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

/* ============================================
   ENGAGEMENT ELEMENTS
   ============================================ */

/* Floating Action Button */
.fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: var(--text-xl);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  cursor: pointer;
  transition: transform var(--transition-base);
  z-index: 100;
}

.fab:hover {
  transform: scale(1.1);
}

/* Streak Counter */
.streak-counter {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: linear-gradient(135deg, var(--accent-600), var(--accent-500));
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: var(--text-sm);
}

.streak-counter::before {
  content: '🔥';
}

/* Achievement Popup */
.achievement-popup {
  position: fixed;
  bottom: 100px;
  right: 24px;
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  padding: var(--space-4);
  border: 1px solid var(--gold);
  box-shadow: var(--shadow-xl);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  z-index: 1000;
  animation: slideIn 0.5s ease;
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
  background: var(--bg-card);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: var(--space-12) 0 var(--space-8);
  margin-top: var(--space-16);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: var(--space-8);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr repeat(3, 1fr);
  }
}

.footer-brand {
  font-size: var(--text-xl);
  font-weight: 800;
  margin-bottom: var(--space-4);
}

.footer-desc {
  color: var(--text-muted);
  font-size: var(--text-sm);
}

.footer-links h4 {
  font-size: var(--text-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
  color: var(--text-secondary);
}

.footer-links ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li {
  margin-bottom: var(--space-2);
}

.footer-links a {
  color: var(--text-muted);
  font-size: var(--text-sm);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary-500);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: var(--space-8);
  padding-top: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  align-items: center;
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
  }
}

/* ============================================
   UTILITIES
   ============================================ */

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

.text-gradient {
  background: linear-gradient(135deg, var(--primary-500), var(--secondary-500));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.mb-4 {
  margin-bottom: var(--space-4);
}

.mb-6 {
  margin-bottom: var(--space-6);
}

.mb-8 {
  margin-bottom: var(--space-8);
}

.mt-8 {
  margin-top: var(--space-8);
}

.mt-12 {
  margin-top: var(--space-12);
}

.hidden {
  display: none;
}

@media (min-width: 768px) {
  .md-block {
    display: block;
  }
  
  .md-flex {
    display: flex;
  }
}

/* ============================================
   ANIMATIONS
   ============================================ */

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

.animate-pulse {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes bounce {
  0%, 100% {
    transform: translateY(-25%);
    animation-timing-function: cubic-bezier(0.8, 0, 1, 1);
  }
  50% {
    transform: translateY(0);
    animation-timing-function: cubic-bezier(0, 0, 0.2, 1);
  }
}

.animate-bounce {
  animation: bounce 1s infinite;
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   RESPONSIVE ADJUSTMENTS
   ============================================ */

@media (max-width: 767px) {
  h1 {
    font-size: var(--text-3xl);
  }
  
  h2 {
    font-size: var(--text-2xl);
  }
  
  .card {
    padding: var(--space-4);
  }
  
  .hero {
    padding-top: 100px;
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}