/* 10xBoost Course Platform - Design System
   Style: Glassmorphism
   Colors: Purple Tech + Gold CTA
   Typography: Space Grotesk / DM Sans
*/

/* ============================================
   CSS Variables (Design Tokens)
   ============================================ */
:root {
  /* Colors */
  --primary: #8B5CF6;
  --primary-hover: #7C3AED;
  --secondary: #A78BFA;
  --cta: #FBBF24;
  --cta-hover: #F59E0B;
  --background: #0F0F23;
  --background-secondary: #1A1A2E;
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --border: rgba(255, 255, 255, 0.1);
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --success: #10B981;
  --error: #EF4444;

  /* Typography */
  --font-heading: 'Space Grotesk', sans-serif;
  --font-body: 'DM Sans', sans-serif;

  /* 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;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 20px rgba(139, 92, 246, 0.3);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 200ms ease;
  --transition-slow: 300ms ease;

  /* Z-index scale */
  --z-dropdown: 10;
  --z-sticky: 20;
  --z-fixed: 30;
  --z-modal-backdrop: 40;
  --z-modal: 50;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--background);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Background gradient */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse at top left, rgba(139, 92, 246, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse at bottom right, rgba(167, 139, 250, 0.1) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.2;
}

a {
  color: inherit;
  text-decoration: none;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ============================================
   Typography
   ============================================ */
.text-xs { font-size: 0.75rem; }
.text-sm { font-size: 0.875rem; }
.text-base { font-size: 1rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }
.text-2xl { font-size: 1.5rem; }
.text-3xl { font-size: 1.875rem; }
.text-4xl { font-size: 2.25rem; }
.text-5xl { font-size: 3rem; }

.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); }
.text-accent { color: var(--primary); }
.text-cta { color: var(--cta); }

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

@media (min-width: 768px) {
  .container {
    padding: 0 var(--spacing-xl);
  }
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

.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); }

@media (min-width: 640px) {
  .sm\:grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
}

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

@media (min-width: 1024px) {
  .lg\:grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
  .lg\:grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
}

/* ============================================
   Glassmorphism Components
   ============================================ */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
}

.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
  position: fixed;
  top: var(--spacing-md);
  left: var(--spacing-md);
  right: var(--spacing-md);
  z-index: var(--z-fixed);
  background: rgba(15, 15, 35, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-sm) var(--spacing-lg);
}

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

.navbar-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
}

.navbar-brand svg {
  width: 32px;
  height: 32px;
  color: var(--primary);
}

.navbar-links {
  display: none;
  align-items: center;
  gap: var(--spacing-lg);
}

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

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

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

.navbar-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.mobile-menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  color: var(--text-primary);
  cursor: pointer;
}

@media (min-width: 768px) {
  .mobile-menu-btn {
    display: none;
  }
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: 80px;
  left: var(--spacing-md);
  right: var(--spacing-md);
  background: rgba(15, 15, 35, 0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  z-index: var(--z-fixed);
}

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

.mobile-menu-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.mobile-menu-link {
  color: var(--text-secondary);
  font-weight: 500;
  padding: var(--spacing-sm) 0;
  transition: color var(--transition-fast);
  cursor: pointer;
}

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

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-weight: 600;
  font-size: 0.875rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  cursor: pointer;
  white-space: nowrap;
}

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

.btn-primary:hover {
  background: var(--primary-hover);
  box-shadow: var(--shadow-glow);
}

.btn-cta {
  background: var(--cta);
  color: var(--background);
}

.btn-cta:hover {
  background: var(--cta-hover);
  box-shadow: 0 0 20px rgba(251, 191, 36, 0.3);
}

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

.btn-outline:hover {
  background: var(--glass-bg);
  border-color: var(--primary);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  color: var(--text-primary);
  background: var(--glass-bg);
}

.btn-lg {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 1rem;
}

.btn-sm {
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: 0.75rem;
}

/* ============================================
   Cards
   ============================================ */
.card {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  cursor: pointer;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.card-image {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.card:hover .card-image img {
  transform: scale(1.05);
}

.card-badge {
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  background: var(--cta);
  color: var(--background);
  font-size: 0.75rem;
  font-weight: 600;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
}

.card-content {
  padding: var(--spacing-lg);
}

.card-title {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.card-description {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-price {
  display: flex;
  align-items: baseline;
  gap: var(--spacing-sm);
}

.card-price-current {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--cta);
}

.card-price-original {
  font-size: 1rem;
  color: var(--text-muted);
  text-decoration: line-through;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 100px;
  padding-bottom: var(--spacing-3xl);
}

.hero-content {
  max-width: 800px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: 0.875rem;
  color: var(--secondary);
  margin-bottom: var(--spacing-lg);
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
  line-height: 1.1;
}

@media (min-width: 768px) {
  .hero-title {
    font-size: 3.5rem;
  }
}

@media (min-width: 1024px) {
  .hero-title {
    font-size: 4rem;
  }
}

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

.hero-description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 600px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

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

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

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

@media (min-width: 768px) {
  .section-title {
    font-size: 2.5rem;
  }
}

.section-description {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================
   Progress Bar
   ============================================ */
.progress-bar {
  width: 100%;
  height: 6px;
  background: var(--glass-bg);
  border-radius: var(--radius-full);
  overflow: hidden;
}

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

/* ============================================
   Video Player
   ============================================ */
.video-container {
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--background-secondary);
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 1px solid var(--glass-border);
}

.video-container video {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.video-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.4);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.video-container:hover .video-overlay {
  opacity: 1;
}

.video-play-btn {
  width: 72px;
  height: 72px;
  background: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  cursor: pointer;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.video-play-btn:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-glow);
}

/* ============================================
   Sidebar (Course Navigation)
   ============================================ */
.sidebar {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  height: fit-content;
  position: sticky;
  top: 100px;
}

.sidebar-title {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
}

.sidebar-list {
  list-style: none;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.sidebar-item:hover {
  background: rgba(139, 92, 246, 0.1);
}

.sidebar-item.active {
  background: rgba(139, 92, 246, 0.2);
}

.sidebar-item-number {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 600;
}

.sidebar-item.completed .sidebar-item-number {
  background: var(--success);
  border-color: var(--success);
  color: white;
}

.sidebar-item-title {
  flex: 1;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.sidebar-item.active .sidebar-item-title {
  color: var(--text-primary);
}

/* ============================================
   Form Elements
   ============================================ */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.form-input {
  width: 100%;
  padding: var(--spacing-md);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 1rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.2);
}

.form-input::placeholder {
  color: var(--text-muted);
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--background-secondary);
  border-top: 1px solid var(--glass-border);
  padding: var(--spacing-2xl) 0;
}

.footer-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

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

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-family: var(--font-heading);
  font-weight: 700;
}

.footer-links {
  display: flex;
  gap: var(--spacing-lg);
}

.footer-link {
  color: var(--text-secondary);
  font-size: 0.875rem;
  transition: color var(--transition-fast);
  cursor: pointer;
}

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

.footer-copyright {
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* ============================================
   Avatar
   ============================================ */
.avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--glass-bg);
  border: 2px solid var(--glass-border);
}

.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.avatar-sm {
  width: 32px;
  height: 32px;
}

.avatar-lg {
  width: 56px;
  height: 56px;
}

/* ============================================
   Utility Classes
   ============================================ */
.hidden { display: none !important; }
.block { display: block; }
.inline-block { display: inline-block; }
.w-full { width: 100%; }
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

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

.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

/* ============================================
   Animations
   ============================================ */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

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

.animate-fade-in {
  animation: fadeIn 0.5s ease forwards;
}

.animate-pulse {
  animation: pulse 2s infinite;
}

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

/* ============================================
   Loading Spinner
   ============================================ */
.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--glass-border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* ============================================
   Toast / Notification
   ============================================ */
.toast {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  z-index: var(--z-modal);
  transform: translateY(100px);
  opacity: 0;
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.toast-success {
  border-color: var(--success);
}

.toast-error {
  border-color: var(--error);
}