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

:root {
  /* Light Mode Colors */
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --secondary-color: #10b981;
  --accent-color: #f59e0b;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --text-light: #9ca3af;
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-accent: #f3f4f6;
  --border-color: #e5e7eb;
  --shadow-color: rgba(0, 0, 0, 0.1);
  --shadow-heavy-color: rgba(0, 0, 0, 0.15);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --gradient-secondary: linear-gradient(135deg, #10b981 0%, #059669 100%);
  --gradient-accent: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  
  /* Spacing */
  --container-max-width: 1200px;
  --container-padding: 1rem;
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* Transitions */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
}

html.dark {
  /* Dark Mode Colors */
  --primary-color: #818cf8;
  --primary-dark: #a78bfa;
  --secondary-color: #34d399;
  --accent-color: #fbbF24;
  --text-primary: #f9fafb;
  --text-secondary: #d1d5db;
  --text-light: #9ca3af;
  --bg-primary: #111827;
  --bg-secondary: #1f2937;
  --bg-accent: #374151;
  --border-color: #374151;
  --shadow-color: rgba(0, 0, 0, 0.2);
  --shadow-heavy-color: rgba(0, 0, 0, 0.3);
}

body {
  font-family: var(--font-family);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Container */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.25;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }

p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 4px 6px var(--shadow-color);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 25px var(--shadow-heavy-color);
}

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

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

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

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

.btn-large {
  padding: 1rem 2rem;
  font-size: var(--font-size-base);
}

.btn-small {
  padding: 0.5rem 1rem;
  font-size: var(--font-size-xs);
}

.btn-full {
  width: 100%;
}

/* Gradient Text */
.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: color-mix(in srgb, var(--bg-primary) 95%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem var(--container-padding);
  max-width: var(--container-max-width);
  margin: 0 auto;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: var(--font-size-xl);
  color: var(--text-primary);
  text-decoration: none;
}

.logo-icon {
  font-size: var(--font-size-2xl);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

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

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.theme-toggle-btn {
  background: var(--bg-accent);
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: all var(--transition-normal);
}
.theme-toggle-btn:hover {
  transform: rotate(15deg);
}
.theme-toggle-btn .moon-icon { display: none; }
html.dark .theme-toggle-btn .sun-icon { display: none; }
html.dark .theme-toggle-btn .moon-icon { display: block; }

.nav-toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 0.25rem;
}

.nav-toggle span {
  width: 1.5rem;
  height: 0.125rem;
  background: var(--text-primary);
  transition: all var(--transition-fast);
}

/* Hero Section */
.hero {
  padding: 8rem 0 4rem;
  background: linear-gradient(135deg, color-mix(in srgb, var(--bg-secondary) 50%, transparent) 0%, var(--bg-primary) 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 1.5rem;
}

.hero-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.hero-stats {
  display: flex;
  gap: 2rem;
  margin-bottom: 2rem;
}

.stat {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--primary-color);
}

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

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero-image img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-xl);
  box-shadow: 0 10px 25px var(--shadow-heavy-color);
}

/* Section Styles */
section {
  padding: 5rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title {
  margin-bottom: 1rem;
}

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

/* Courses Section */
.courses {
  background: var(--bg-secondary);
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
}

.course-card {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: 0 1px 3px var(--shadow-color);
  transition: all var(--transition-normal);
  border: 1px solid var(--border-color);
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 25px var(--shadow-heavy-color);
}

.course-image {
  position: relative;
  height: 200px;
  overflow: hidden;
}

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

.course-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: var(--gradient-accent);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  font-weight: 600;
}

.course-content {
  padding: 1.5rem;
}

.course-title {
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.course-description {
  font-size: var(--font-size-sm);
  margin-bottom: 1rem;
}

.course-meta {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.course-meta span {
  font-size: var(--font-size-xs);
  color: var(--text-light);
}

.course-price {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.price-current {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--primary-color);
}

.price-original {
  font-size: var(--font-size-sm);
  color: var(--text-light);
  text-decoration: line-through;
}

/* Testimonials Section */
.testimonials {
  background: var(--bg-secondary);
}
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}
.testimonial-card {
  background: var(--bg-primary);
  padding: 2rem;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-color);
}
.testimonial-text {
  font-style: italic;
  margin-bottom: 1.5rem;
  position: relative;
  padding-left: 1.5rem;
}
.testimonial-text::before {
  content: '“';
  position: absolute;
  left: -0.5rem;
  top: -1rem;
  font-size: 3rem;
  color: var(--primary-color);
  opacity: 0.5;
}
.testimonial-author {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.author-avatar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
}
.author-name {
  margin: 0;
  font-size: var(--font-size-base);
}
.author-role {
  margin: 0;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}


/* Challenges Section */
.challenges-content {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 3rem;
  align-items: start;
}

.leaderboard {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: 0 4px 6px var(--shadow-color);
  border: 1px solid var(--border-color);
}

.leaderboard-title {
  margin-bottom: 1.5rem;
  text-align: center;
}

.leaderboard-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.leaderboard-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.leaderboard-item:hover {
  background: var(--bg-accent);
}

.rank {
  font-weight: 700;
  width: 2rem;
  text-align: center;
}

.rank-1 { background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%); color: white; }
.rank-2 { background: linear-gradient(135deg, #9ca3af 0%, #6b7280 100%); color: white; }
.rank-3 { background: linear-gradient(135deg, #f97316 0%, #ea580c 100%); color: white; }

.name {
  flex: 1;
  margin-left: 1rem;
  font-weight: 500;
}

.points {
  font-weight: 600;
  color: var(--primary-color);
}

.challenge-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.challenge-card {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: 1.5rem;
  text-align: center;
  box-shadow: 0 1px 3px var(--shadow-color);
  transition: all var(--transition-normal);
  border: 1px solid var(--border-color);
}

.challenge-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 6px var(--shadow-color);
}

.challenge-icon {
  font-size: var(--font-size-4xl);
  margin-bottom: 1rem;
}

.challenge-title {
  margin-bottom: 0.5rem;
}

.challenge-description {
  font-size: var(--font-size-sm);
  margin-bottom: 1rem;
}

.challenge-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.difficulty {
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  font-weight: 600;
}

.easy { background: #dcfce7; color: #16a34a; }
.medium { background: #fef3c7; color: #d97706; }
.hard { background: #fecaca; color: #dc2626; }

.points {
  font-weight: 600;
  color: var(--secondary-color);
}

/* Live Sessions Section */
.live-sessions {
  background: var(--bg-secondary);
}

.sessions-content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 3rem;
  align-items: start;
}

.session-schedule {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: 0 4px 6px var(--shadow-color);
  border: 1px solid var(--border-color);
}

.schedule-title {
  margin-bottom: 1.5rem;
}

.session-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.session-item {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
}

.session-item:hover {
  border-color: var(--primary-color);
  box-shadow: 0 1px 3px var(--shadow-color);
}

.session-time {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 4rem;
  text-align: center;
}

.day {
  font-size: var(--font-size-xs);
  color: var(--text-light);
  text-transform: uppercase;
}

.date {
  font-weight: 700;
  color: var(--primary-color);
}

.time {
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
}

.session-details {
  flex: 1;
}

.session-topic {
  margin-bottom: 0.25rem;
  font-size: var(--font-size-base);
}

.session-mentor {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.session-spots {
  font-size: var(--font-size-xs);
  color: var(--secondary-color);
  font-weight: 500;
}

.session-features {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.feature-card {
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  box-shadow: 0 1px 3px var(--shadow-color);
  border: 1px solid var(--border-color);
}

.feature-icon {
  font-size: var(--font-size-3xl);
  margin-bottom: 1rem;
}

.feature-title {
  margin-bottom: 0.5rem;
}

.feature-description {
  font-size: var(--font-size-sm);
}

/* Certificates Section */
.certificates-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.certificate-preview {
  display: flex;
  justify-content: center;
}

.certificate-card {
  background: var(--bg-primary);
  border: 2px solid var(--primary-color);
  border-radius: var(--radius-xl);
  padding: 2rem;
  width: 100%;
  max-width: 400px;
  box-shadow: 0 10px 25px var(--shadow-heavy-color);
  text-align: center;
}

.certificate-header {
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1rem;
}

.certificate-title {
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.certificate-logo {
  font-size: var(--font-size-lg);
  font-weight: 600;
}

.certificate-body {
  margin-bottom: 1.5rem;
}

.certificate-text {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.certificate-name {
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.certificate-course {
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.certificate-date {
  font-size: var(--font-size-sm);
  color: var(--text-light);
}

.certificate-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--font-size-xs);
  color: var(--text-light);
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
}

.certificate-info {
  background: var(--bg-secondary);
  border-radius: var(--radius-xl);
  padding: 2rem;
}

.info-title {
  margin-bottom: 1.5rem;
}

.info-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 2rem;
}

.info-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.info-icon {
  font-size: var(--font-size-lg);
}

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

/* Pricing Section */
.pricing {
  background: var(--bg-secondary);
}

.pricing-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  max-width: 1000px;
  margin: 0 auto;
}

.pricing-card {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: 2rem;
  text-align: center;
  box-shadow: 0 1px 3px var(--shadow-color);
  transition: all var(--transition-normal);
  position: relative;
  border: 1px solid var(--border-color);
}

.pricing-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 25px var(--shadow-heavy-color);
}

.pricing-card.featured {
  border: 2px solid var(--primary-color);
  transform: scale(1.05);
}

.pricing-badge {
  position: absolute;
  top: -0.5rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-primary);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  font-weight: 600;
}

.pricing-header {
  margin-bottom: 2rem;
}

.pricing-title {
  margin-bottom: 1rem;
}

.pricing-price {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.25rem;
}

.price {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  color: var(--primary-color);
}

.period {
  font-size: var(--font-size-base);
  color: var(--text-secondary);
}

.pricing-features {
  margin-bottom: 2rem;
  text-align: left;
}

.feature-item {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--bg-accent);
  font-size: var(--font-size-sm);
}

.feature-item:last-child {
  border-bottom: none;
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  padding: 3rem 0 1rem;
  border-top: 1px solid var(--border-color);
}

html.dark .footer {
  background: #111827;
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 3rem;
  margin-bottom: 2rem;
}

.footer-brand .logo {
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.footer-description {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 2rem;
}

.footer-title {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: var(--font-size-base);
}

.footer-link {
  display: block;
  color: var(--text-secondary);
  text-decoration: none;
  margin-bottom: 0.5rem;
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
  text-align: center;
}

.footer-copyright {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  margin: 0;
}

/* AI Chat Widget */
#ai-chat-widget {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1001;
}
#chat-toggle-button {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: white;
  border: none;
  font-size: 1.8rem;
  cursor: pointer;
  box-shadow: var(--shadow-heavy);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.3s;
}
#chat-toggle-button:hover {
  transform: scale(1.1);
}
#chat-toggle-button .close-icon { display: none; }
#chat-window {
  position: absolute;
  bottom: 80px;
  right: 0;
  width: 350px;
  height: 500px;
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-heavy);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: translateY(20px) scale(0.9);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.3s, opacity 0.3s;
}
#ai-chat-widget.open #chat-window {
  transform: translateY(0) scale(1);
  opacity: 1;
  pointer-events: auto;
}
#ai-chat-widget.open #chat-toggle-button .icon { display: none; }
#ai-chat-widget.open #chat-toggle-button .close-icon { display: block; }
#chat-header {
  padding: 1rem;
  background: var(--gradient-primary);
  color: white;
  text-align: center;
}
#chat-header h4 { color: white; margin: 0; }
#chat-header p { color: white; opacity: 0.8; font-size: 0.8rem; margin: 0; }
#chat-messages {
  flex: 1;
  padding: 1rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.chat-message {
  padding: 0.75rem 1rem;
  border-radius: var(--radius-lg);
  max-width: 80%;
  line-height: 1.4;
}
.chat-message.user {
  background: var(--primary-color);
  color: white;
  align-self: flex-end;
  border-bottom-right-radius: var(--radius-sm);
}
.chat-message.bot {
  background: var(--bg-accent);
  color: var(--text-primary);
  align-self: flex-start;
  border-bottom-left-radius: var(--radius-sm);
}
#chat-input-container {
  display: flex;
  padding: 1rem;
  border-top: 1px solid var(--border-color);
}
#chat-input {
  flex: 1;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  color: var(--text-primary);
}
#chat-send-button {
  margin-left: 0.5rem;
  padding: 0 1rem;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
}

/* Live Activity Notification */
#activity-notification {
  position: fixed;
  bottom: 2rem;
  left: 2rem;
  background: color-mix(in srgb, var(--bg-secondary) 90%, transparent);
  backdrop-filter: blur(5px);
  color: var(--text-primary);
  padding: 1rem 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-heavy);
  z-index: 1002;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  transform: translateY(200%);
  transition: transform 0.5s ease-in-out;
}
#activity-notification.show {
  transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    padding: 1rem;
    box-shadow: var(--shadow-medium);
    gap: 1rem;
    border-bottom-left-radius: var(--radius-lg);
    border-bottom-right-radius: var(--radius-lg);
  }
  .nav-menu.nav-menu-active { display: flex; }
  .nav-toggle { display: flex; }
  .nav-toggle.nav-toggle-active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .nav-toggle.nav-toggle-active span:nth-child(2) { opacity: 0; }
  .nav-toggle.nav-toggle-active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }
  
  .hero-content { grid-template-columns: 1fr; text-align: center; gap: 2rem; }
  .hero-title { font-size: var(--font-size-3xl); }
  .hero-actions { justify-content: center; }
  
  .courses-grid, .testimonials-grid { grid-template-columns: 1fr; }
  .challenges-content, .sessions-content, .certificates-content, .footer-content { grid-template-columns: 1fr; }
  
  .pricing-cards { grid-template-columns: 1fr; }
  .pricing-card.featured { transform: none; }
}

@media (max-width: 480px) {
  .container { padding: 0 1rem; }
  .hero { padding: 6rem 0 3rem; }
  .hero-stats { flex-direction: column; gap: 1rem; text-align: center; }
  .hero-actions { flex-direction: column; }
  .session-item { flex-direction: column; text-align: center; gap: 1rem; }
  .certificate-footer { flex-direction: column; gap: 0.5rem; }
  #ai-chat-widget { bottom: 1rem; right: 1rem; }
  #chat-window { width: calc(100vw - 2rem); height: calc(100vh - 8rem); }
}

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

.course-card, .challenge-card, .feature-card, .pricing-card, .testimonial-card {
  animation: fadeInUp 0.6s ease-out;
}

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}

/* Focus styles for accessibility */
.btn:focus, .nav-link:focus, input:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}