/* ===== ADVANCED CSS RESET & VARIABLES ===== */
:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #818cf8;
  --secondary: #f59e0b;
  --secondary-dark: #d97706;
  --accent: #10b981;
  --accent-dark: #059669;
  --danger: #ef4444;
  --warning: #f59e0b;
  --success: #10b981;
  
  --dark-1: #0f172a;
  --dark-2: #1e293b;
  --dark-3: #334155;
  --light-1: #f8fafc;
  --light-2: #e2e8f0;
  --light-3: #cbd5e1;
  
  --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --gradient-secondary: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
  --gradient-accent: linear-gradient(135deg, #10b981 0%, #34d399 100%);
  --gradient-dark: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  --gradient-hero: linear-gradient(135deg, #0f172a 0%, #334155 50%, #1e293b 100%);
  
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.2);
  --shadow-xl: 0 25px 50px -12px rgba(0,0,0,0.25);
  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.3);
  
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;
  
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  
  --font-primary: 'Outfit', 'Inter', system-ui, sans-serif;
  --font-mono: 'Fira Code', 'Courier New', monospace;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  background: var(--dark-1);
  color: var(--light-1);
  overflow-x: hidden;
  line-height: 1.6;
  position: relative;
  cursor: default;
}

/* ===== SLIDE SYSTEM - FIXED POSITIONING ===== */
.slide {
  min-height: 100vh;
  width: 100%;
  position: absolute;
  top: 0;
  left: 0;
  display: none;
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition-slow);
  overflow-y: auto;
}

.slide.active {
  display: block;
  opacity: 1;
  transform: translateY(0);
}

.slide-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
}

/* Background patterns for different slides */
.bg-pattern {
  background: 
    radial-gradient(circle at 20% 80%, rgba(99, 102, 241, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(245, 158, 11, 0.05) 0%, transparent 50%);
}

.bg-grid {
  background-image: 
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 50px 50px;
}

.bg-code {
  background: 
    linear-gradient(45deg, var(--dark-2) 25%, transparent 25%),
    linear-gradient(-45deg, var(--dark-2) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, var(--dark-2) 75%),
    linear-gradient(-45deg, transparent 75%, var(--dark-2) 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
  opacity: 0.1;
}

.bg-features {
  background: 
    radial-gradient(circle at 30% 30%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 70% 70%, rgba(16, 185, 129, 0.1) 0%, transparent 50%);
}

.bg-quiz {
  background: 
    linear-gradient(135deg, transparent 0%, rgba(99, 102, 241, 0.05) 100%);
}

.bg-final {
  background: 
    radial-gradient(circle at 50% 50%, rgba(16, 185, 129, 0.1) 0%, transparent 70%),
    radial-gradient(circle at 80% 20%, rgba(99, 102, 241, 0.1) 0%, transparent 50%);
}

/* ===== CINEMATIC INTRO SLIDE ===== */
.intro-slide {
  background: var(--gradient-hero);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
}

.cinematic-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 80%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(245, 158, 11, 0.1) 0%, transparent 50%);
  animation: float 6s ease-in-out infinite;
}

.particles-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.particle {
  position: absolute;
  background: var(--primary);
  border-radius: 50%;
  animation: float-particle 20s linear infinite;
}

@keyframes float-particle {
  0% {
    transform: translateY(100vh) rotate(0deg);
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  90% {
    opacity: 1;
  }
  100% {
    transform: translateY(-100px) rotate(360deg);
    opacity: 0;
  }
}

.intro-content {
  position: relative;
  z-index: 2;
  max-width: 1200px;
  padding: 2rem;
  margin: 0 auto;
}

.logo-reveal {
  margin-bottom: 3rem;
  position: relative;
}

.logo-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 200px;
  height: 200px;
  background: var(--gradient-primary);
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.5;
  animation: pulse-glow 3s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% { opacity: 0.3; transform: translate(-50%, -50%) scale(1); }
  50% { opacity: 0.6; transform: translate(-50%, -50%) scale(1.1); }
}

.cinematic-logo {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid rgba(255,255,255,0.1);
  box-shadow: var(--shadow-glow);
  animation: logo-enter 3.5s ease-out;
}

@keyframes logo-enter {
  0% {
    opacity: 0;
    transform: scale(0.5) rotate(-180deg);
  }
  100% {
    opacity: 1;
    transform: scale(1) rotate(0deg);
  }
}

.title-sequence {
  margin-bottom: 3rem;
}

.main-title {
  font-size: clamp(2.5rem, 6vw, 5rem);
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.1;
}

.title-word {
  display: inline-block;
  opacity: 0;
  transform: translateY(30px);
  animation: title-word 0.8s ease forwards;
}

.title-word:nth-child(1) { animation-delay: 0.5s; }
.title-word:nth-child(2) { animation-delay: 1s; }
.title-word:nth-child(3) { animation-delay: 1.5s; }

@keyframes title-word {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.subtitle-reveal {
  opacity: 0;
  animation: subtitle-enter 1s ease 2s forwards;
}

@keyframes subtitle-enter {
  to {
    opacity: 1;
  }
}

.course-subtitle {
  font-size: 1.5rem;
  color: var(--light-2);
  margin-bottom: 1rem;
}

.title-underline {
  width: 100px;
  height: 4px;
  background: var(--gradient-primary);
  margin: 0 auto;
  border-radius: 2px;
  animation: underline-grow 1s ease 2.5s forwards;
  transform: scaleX(0);
  transform-origin: center;
}

@keyframes underline-grow {
  to {
    transform: scaleX(1);
  }
}

.instructor-card {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  background: rgba(255,255,255,0.05);
  padding: 1.5rem;
  border-radius: var(--border-radius-lg);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.1);
  margin-bottom: 3rem;
  animation: card-enter 1s ease 3s forwards;
  opacity: 0;
  transform: translateY(20px);
}

@keyframes card-enter {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.instructor-avatar img {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--primary);
}

.instructor-info h3 {
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
}

.instructor-info p {
  color: var(--light-3);
  font-size: 0.9rem;
}

.start-pulse {
  animation: pulse-cta 2s ease-in-out infinite;
}

.start-button {
  background: var(--gradient-primary);
  color: white;
  border: none;
  padding: 1.5rem 3rem;
  font-size: 1.25rem;
  font-weight: 600;
  border-radius: 50px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-glow);
}

.button-glow {
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: var(--transition-normal);
}

.start-button:hover .button-glow {
  left: 100%;
}

.start-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

@keyframes pulse-cta {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

.scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  40% {
    transform: translateX(-50%) translateY(-10px);
  }
  60% {
    transform: translateX(-50%) translateY(-5px);
  }
}

/* ===== CONTENT SLIDES - FIXED POSITIONING ===== */
.slide-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 6rem 2rem 2rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  z-index: 1;
}

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

.chapter-badge {
  display: inline-block;
  background: var(--gradient-primary);
  color: white;
  padding: 0.5rem 1.5rem;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.slide-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--light-1) 0%, var(--light-2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.slide-subtitle {
  font-size: 1.25rem;
  color: var(--light-3);
}

/* ===== CONCEPT CARDS ===== */
.concept-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2rem;
}

.concept-card {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  border: 1px solid rgba(255,255,255,0.1);
  overflow: hidden;
  transition: var(--transition-normal);
  opacity: 0;
  transform: translateY(20px);
}

.concept-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.concept-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

.card-header {
  padding: 1.5rem;
  background: rgba(255,255,255,0.02);
  border-bottom: 1px solid rgba(255,255,255,0.1);
  display: flex;
  align-items: center;
  gap: 1rem;
}

.card-icon {
  font-size: 1.5rem;
  width: 50px;
  height: 50px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: white;
}

.card-header h3 {
  font-size: 1.25rem;
  color: var(--light-1);
}

.card-content {
  padding: 1.5rem;
}

.card-content ul {
  list-style: none;
  margin-top: 1rem;
}

.card-content li {
  padding: 0.5rem 0;
  position: relative;
  padding-left: 1.5rem;
}

.card-content li:before {
  content: "•";
  color: var(--primary);
  position: absolute;
  left: 0;
  font-weight: bold;
}

/* ===== SLIDE 3: HTML CHARACTERISTICS ===== */
.comparison-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-top: 2rem;
}

.advantages-section, .disadvantages-section {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.advantages-section {
  border-left: 4px solid var(--success);
}

.disadvantages-section {
  border-left: 4px solid var(--danger);
}

.section-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  text-align: center;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

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

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.5rem;
  background: rgba(255,255,255,0.02);
  border-radius: var(--border-radius-md);
  border: 1px solid rgba(255,255,255,0.05);
  transition: var(--transition-normal);
}

.feature-item:hover {
  transform: translateX(10px);
  border-color: rgba(255,255,255,0.1);
}

.feature-text h4 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--light-1);
}

.feature-text p {
  color: var(--light-3);
  font-size: 0.95rem;
}

/* ===== SLIDE 4: HTML EDITORS ===== */
.editors-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.editor-card {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  text-align: center;
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.editor-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

.editor-card.featured {
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

.editor-card.featured:before {
  content: "Recommended";
  position: absolute;
  top: 10px;
  right: -30px;
  background: var(--gradient-primary);
  color: white;
  padding: 0.25rem 2rem;
  font-size: 0.8rem;
  font-weight: 600;
  transform: rotate(45deg);
}

.editor-icon {
  width: 80px;
  height: 80px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: white;
}

.editor-card h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--light-1);
}

.editor-card p {
  color: var(--light-3);
  margin-bottom: 1.5rem;
  line-height: 1.5;
}

.editor-tags {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tag {
  background: rgba(255,255,255,0.1);
  color: var(--light-2);
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
}

.file-extension-note {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--border-radius-md);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 2rem;
}

.note-icon {
  width: 40px;
  height: 40px;
  background: var(--gradient-accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: white;
  flex-shrink: 0;
}

.file-extension-note p {
  margin: 0;
  color: var(--light-2);
}

.file-extension-note code {
  background: rgba(255,255,255,0.1);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  color: var(--accent);
}

/* ===== SLIDE 5: HTML WITH CSS & JS ===== */
.web-trio {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-bottom: 3rem;
}

.tech-card {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  text-align: center;
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.tech-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-glow);
}

.html-card:hover {
  border-color: var(--primary);
}

.css-card:hover {
  border-color: var(--secondary);
}

.js-card:hover {
  border-color: var(--warning);
}

.tech-icon {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: white;
}

.html-card .tech-icon {
  background: var(--gradient-primary);
}

.css-card .tech-icon {
  background: var(--gradient-secondary);
}

.js-card .tech-icon {
  background: var(--gradient-accent);
}

.tech-card h3 {
  font-size: 1.75rem;
  margin-bottom: 0.5rem;
  color: var(--light-1);
}

.tech-role {
  font-size: 1rem;
  color: var(--light-3);
  margin-bottom: 1.5rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.tech-card p {
  color: var(--light-2);
  margin-bottom: 1.5rem;
  line-height: 1.5;
}

.tech-card ul {
  list-style: none;
  text-align: left;
}

.tech-card li {
  padding: 0.5rem 0;
  color: var(--light-3);
  position: relative;
  padding-left: 1.5rem;
}

.tech-card li:before {
  content: "▸";
  color: var(--primary);
  position: absolute;
  left: 0;
  font-weight: bold;
}

.integration-example {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.integration-example h4 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: var(--light-1);
}

.code-example {
  background: var(--dark-2);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.1);
}

.code-example pre {
  margin: 0;
  padding: 1.5rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.5;
}

.code-example code {
  color: #e2e8f0;
}

/* ===== SLIDE 6: FIRST HTML FILE ===== */
.demo-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
  flex: 1;
}

.code-editor, .demo-preview {
  background: var(--dark-2);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.1);
}

.editor-header, .preview-header {
  background: var(--dark-3);
  padding: 1rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.editor-dots, .browser-dots {
  display: flex;
  gap: 0.5rem;
}

.editor-dots span, .browser-dots span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.editor-dots span:nth-child(1) { background: #ef4444; }
.editor-dots span:nth-child(2) { background: #f59e0b; }
.editor-dots span:nth-child(3) { background: #10b981; }

.browser-dots span:nth-child(1) { background: #ef4444; }
.browser-dots span:nth-child(2) { background: #f59e0b; }
.browser-dots span:nth-child(3) { background: #10b981; }

.editor-title, .preview-url {
  color: var(--light-2);
  font-size: 0.9rem;
}

.editor-content, .preview-content {
  padding: 1.5rem;
  height: 300px;
  overflow: auto;
}

.editor-content pre {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.5;
}

.preview-content {
  background: white;
  color: var(--dark-1);
  font-family: system-ui, sans-serif;
}

.preview-content h1 {
  color: #1e293b;
  margin-bottom: 1rem;
}

.preview-content p {
  color: #475569;
  margin-bottom: 0.5rem;
}

.creation-steps {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.creation-steps h3 {
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  color: var(--light-1);
}

.steps-list {
  list-style: none;
  counter-reset: step-counter;
}

.steps-list li {
  counter-increment: step-counter;
  padding: 1rem 0 1rem 3rem;
  position: relative;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.steps-list li:last-child {
  border-bottom: none;
}

.steps-list li:before {
  content: counter(step-counter);
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 2rem;
  height: 2rem;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: white;
  font-size: 0.9rem;
}

.steps-list code {
  background: rgba(255,255,255,0.1);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  color: var(--primary-light);
}

/* ===== SLIDE 7: HTML TAGS & ELEMENTS ===== */
.tags-elements-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}

.tags-section, .elements-section, .attributes-section {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.tags-section h3, .elements-section h3, .attributes-section h3 {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--light-1);
  border-bottom: 1px solid rgba(255,255,255,0.1);
  padding-bottom: 0.5rem;
}

.concept-explanation {
  margin-bottom: 2rem;
}

.concept-explanation p {
  margin-bottom: 1rem;
  color: var(--light-2);
}

.concept-explanation ul {
  list-style: none;
  margin-top: 1rem;
}

.concept-explanation li {
  padding: 0.5rem 0;
  position: relative;
  padding-left: 1.5rem;
  color: var(--light-3);
}

.concept-explanation li:before {
  content: "•";
  color: var(--primary);
  position: absolute;
  left: 0;
  font-weight: bold;
}

.concept-explanation code {
  background: rgba(255,255,255,0.1);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  color: var(--primary-light);
}

.tag-examples, .empty-elements {
  margin-top: 1.5rem;
}

.tag-examples h4, .empty-elements p {
  margin-bottom: 1rem;
  color: var(--light-2);
}

.tags-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag-example {
  background: rgba(99, 102, 241, 0.1);
  color: var(--primary-light);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  border: 1px solid rgba(99, 102, 241, 0.3);
  transition: var(--transition-fast);
}

.tag-example:hover {
  background: rgba(99, 102, 241, 0.2);
  transform: translateY(-2px);
}

.empty-elements {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.empty-tag {
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  border: 1px solid rgba(16, 185, 129, 0.3);
  transition: var(--transition-fast);
}

.empty-tag:hover {
  background: rgba(16, 185, 129, 0.2);
  transform: translateY(-2px);
}

.attribute-example {
  background: var(--dark-2);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.1);
  margin-top: 1rem;
}

.attribute-example h4 {
  background: var(--dark-3);
  padding: 1rem;
  margin: 0;
  font-size: 1rem;
  color: var(--light-2);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.attribute-example pre {
  margin: 0;
  padding: 1.5rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.5;
}

.attribute-example code {
  color: #e2e8f0;
}

/* ===== SLIDE 8: RECAP & NEXT STEPS ===== */
.completion-animation {
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
}

.confetti-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
}

.confetti {
  position: absolute;
  width: 10px;
  height: 10px;
  background: var(--primary);
  animation: confetti-fall 5s linear forwards;
}

@keyframes confetti-fall {
  0% {
    transform: translateY(-100px) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(100vh) rotate(360deg);
    opacity: 0;
  }
}

.trophy {
  font-size: 4rem;
  margin-bottom: 1rem;
  animation: bounce-trophy 2s ease-in-out infinite;
  width: 120px;
  height: 120px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 2rem;
  color: white;
  font-weight: 700;
}

@keyframes bounce-trophy {
  0%, 100% {
    transform: translateY(0) scale(1);
  }
  50% {
    transform: translateY(-20px) scale(1.1);
  }
}

.completion-title {
  font-size: 3rem;
  margin-bottom: 1rem;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.completion-subtitle {
  font-size: 1.5rem;
  color: var(--light-3);
}

.recap-section {
  margin-bottom: 3rem;
}

.recap-section h3 {
  text-align: center;
  margin-bottom: 2rem;
  font-size: 1.5rem;
  color: var(--light-1);
}

.recap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.recap-item {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  text-align: center;
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition-normal);
}

.recap-item:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

.recap-icon {
  width: 60px;
  height: 60px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-weight: 700;
  color: white;
  font-size: 0.9rem;
}

.recap-item h4 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--light-1);
}

.recap-item p {
  color: var(--light-3);
  font-size: 0.9rem;
}

.practice-section {
  margin-bottom: 3rem;
}

.practice-section h3 {
  text-align: center;
  margin-bottom: 2rem;
  font-size: 1.5rem;
  color: var(--light-1);
}

.exercise-card {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
  max-width: 600px;
  margin: 0 auto;
}

.exercise-card h4 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--light-1);
  text-align: center;
}

.exercise-card p {
  color: var(--light-2);
  margin-bottom: 1.5rem;
  text-align: center;
}

.exercise-card ul {
  list-style: none;
  margin-bottom: 2rem;
}

.exercise-card li {
  padding: 0.5rem 0;
  color: var(--light-3);
  position: relative;
  padding-left: 1.5rem;
}

.exercise-card li:before {
  content: "▸";
  color: var(--primary);
  position: absolute;
  left: 0;
  font-weight: bold;
}

.exercise-btn {
  background: var(--gradient-primary);
  color: white;
  border: none;
  padding: 1rem 2rem;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  font-weight: 600;
  transition: var(--transition-normal);
  display: block;
  margin: 0 auto;
  width: 200px;
}

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

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

.cta-button {
  background: var(--gradient-primary);
  color: white;
  border: none;
  padding: 1.5rem 3rem;
  font-size: 1.25rem;
  font-weight: 600;
  border-radius: 50px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-glow);
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

.cta-note {
  color: var(--light-3);
  font-size: 0.9rem;
}

/* ===== PRESENTATION CONTROLS ===== */
.presentation-controls {
  position: fixed;
  top: 2rem;
  right: 2rem;
  z-index: 1000;
  display: flex;
  gap: 1rem;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(10px);
  padding: 0.5rem;
  border-radius: var(--border-radius-md);
  border: 1px solid rgba(255,255,255,0.2);
}

.control-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--border-radius-sm);
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: var(--light-1);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-fast);
}

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

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

.slide-counter {
  color: var(--light-1);
  font-weight: 600;
  font-size: 0.9rem;
  min-width: 50px;
  text-align: center;
}

/* ===== BRANDED LASER POINTER ===== */
.laser-pointer {
  position: fixed;
  width: 30px;
  height: 30px;
  pointer-events: none;
  z-index: 10000;
  opacity: 0;
  transition: opacity 0.2s;
  filter: drop-shadow(0 0 10px rgba(99, 102, 241, 0.8));
  display: flex;
  align-items: center;
  justify-content: center;
}

.laser-pointer.active {
  opacity: 1;
}

.laser-pointer.logo-pointer {
  background: transparent;
  box-shadow: none;
  border: none;
}

.laser-pointer img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 50%;
  animation: logo-pulse 2s ease-in-out infinite;
}

@keyframes logo-pulse {
  0%, 100% {
    transform: scale(1);
    filter: drop-shadow(0 0 8px rgba(99, 102, 241, 0.6));
  }
  50% {
    transform: scale(1.1);
    filter: drop-shadow(0 0 12px rgba(99, 102, 241, 0.9));
  }
}

.laser-trail {
  position: absolute;
  width: 6px;
  height: 6px;
  background: var(--primary);
  border-radius: 50%;
  pointer-events: none;
  opacity: 0.6;
  animation: trail-fade 1s ease-out forwards;
}

@keyframes trail-fade {
  to {
    opacity: 0;
    transform: scale(0.5);
  }
}

/* Style for active laser button */
.control-btn.active {
  background-color: rgba(99, 102, 241, 0.2);
  border-color: rgba(99, 102, 241, 0.8);
}

/* ===== RECORDING INDICATOR ===== */
.recording-indicator {
  position: fixed;
  top: 2rem;
  left: 2rem;
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(239, 68, 68, 0.2);
  padding: 0.5rem 1rem;
  border-radius: 50px;
  border: 1px solid rgba(239, 68, 68, 0.5);
  color: var(--danger);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.recording-dot {
  width: 8px;
  height: 8px;
  background: var(--danger);
  border-radius: 50%;
  animation: recording-pulse 1s ease-in-out infinite;
}

@keyframes recording-pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.5;
    transform: scale(1.2);
  }
}

/* ===== PROGRESS INDICATOR ===== */
.progress-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: rgba(255,255,255,0.1);
  z-index: 1001;
}

.progress-bar {
  height: 100%;
  background: var(--gradient-primary);
  width: 0%;
  transition: width 0.3s ease;
}

/* ===== SLIDE INDICATOR ===== */
.slide-indicator {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 1rem;
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(10px);
  padding: 1rem;
  border-radius: var(--border-radius-md);
  border: 1px solid rgba(255,255,255,0.2);
  color: var(--light-1);
  font-weight: 600;
}

.slide-progress {
  width: 100px;
  height: 4px;
  background: rgba(255,255,255,0.2);
  border-radius: 2px;
  overflow: hidden;
}

.slide-progress-bar {
  height: 100%;
  background: var(--gradient-primary);
  width: 12.5%;
  transition: width 0.3s ease;
}

/* ===== PRESENTER NOTES ===== */
.presenter-notes {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(10px);
  border-top: 1px solid rgba(255,255,255,0.1);
  z-index: 900;
  transform: translateY(100%);
  transition: transform 0.3s ease;
}

.presenter-notes.show {
  transform: translateY(0);
}

.notes-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.notes-header h4 {
  color: var(--light-1);
}

.notes-toggle {
  background: none;
  border: none;
  color: var(--light-2);
  cursor: pointer;
  padding: 0.5rem;
  transition: var(--transition-fast);
}

.notes-toggle:hover {
  color: var(--light-1);
}

.notes-content {
  padding: 2rem;
  max-height: 200px;
  overflow-y: auto;
}

.note {
  display: none;
  padding: 1rem;
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-md);
  border-left: 4px solid var(--primary);
}

.note.active {
  display: block;
  animation: slideUp 0.3s ease;
}

/* ===== SOCIAL TICKER ===== */
.social-ticker {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  background: var(--gradient-primary);
  color: white;
  padding: 1rem 0;
  overflow: hidden;
  z-index: 800;
}

.ticker-content {
  display: flex;
  animation: ticker-scroll 30s linear infinite;
  white-space: nowrap;
}

.ticker-item {
  padding: 0 2rem;
  font-weight: 600;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

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

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
  .slide-content {
    padding: 4rem 1rem 1rem;
  }

  .presentation-controls {
    top: 1rem;
    right: 1rem;
    flex-direction: column;
  }

  .demo-container {
    grid-template-columns: 1fr;
  }

  .concept-cards {
    grid-template-columns: 1fr;
  }

  .comparison-container {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .editors-grid {
    grid-template-columns: 1fr;
  }

  .web-trio {
    grid-template-columns: 1fr;
  }

  .recap-grid {
    grid-template-columns: 1fr;
  }

  .slide-indicator {
    bottom: 1rem;
    right: 1rem;
  }

  .recording-indicator {
    top: 1rem;
    left: 1rem;
  }
}

@media (max-width: 480px) {
  .intro-content {
    padding: 1rem;
  }

  .instructor-card {
    flex-direction: column;
    text-align: center;
  }

  .feature-item {
    flex-direction: column;
    text-align: center;
  }
}

/* ===== UTILITY CLASSES ===== */
.visible {
  opacity: 1 !important;
  transform: translateY(0) !important;
}

.hidden {
  display: none !important;
}

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

.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }

/* ===== VIDEO 2 SPECIFIC STYLES ===== */

/* Element Anatomy Visualization */
.anatomy-card {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
  margin-bottom: 2rem;
}

.anatomy-visual {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin: 2rem 0;
}

.anatomy-part {
  padding: 1.5rem;
  border-radius: var(--border-radius-md);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: var(--transition-normal);
}

.anatomy-part:hover {
  transform: translateX(10px);
}

.start-tag {
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.content {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  margin-left: 2rem;
}

.end-tag {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.part-label {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--light-2);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.anatomy-note {
  text-align: center;
  color: var(--light-3);
  font-style: italic;
  margin-top: 1rem;
}

/* Element Types */
.element-types {
  margin-top: 3rem;
}

.types-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-top: 1.5rem;
}

.type-card {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 1.5rem;
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition-normal);
}

.type-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
}

.type-card h4 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: var(--light-1);
}

.type-card p {
  color: var(--light-3);
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.type-examples {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.type-examples code {
  background: rgba(255,255,255,0.1);
  padding: 0.5rem 0.75rem;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--primary-light);
}

/* Self-Closing Tags */
.self-closing-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}

.syntax-comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin: 2rem 0;
}

.syntax-item {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 1.5rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.syntax-item h4 {
  font-size: 1.1rem;
  margin-bottom: 1rem;
  color: var(--light-1);
  text-align: center;
}

.syntax-item p {
  color: var(--light-3);
  text-align: center;
  margin-top: 1rem;
  font-size: 0.9rem;
}

.void-elements-grid {
  margin-top: 2rem;
}

.void-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.void-card {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-md);
  padding: 1.5rem;
  text-align: center;
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition-normal);
}

.void-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
}

.void-icon {
  width: 50px;
  height: 50px;
  background: var(--gradient-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-weight: 700;
  color: white;
  font-size: 0.9rem;
}

.void-card h4 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--light-1);
}

.void-card p {
  color: var(--light-3);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.void-card code {
  background: rgba(255,255,255,0.1);
  padding: 0.5rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--primary-light);
}

/* Attributes */
.attributes-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}

.attributes-intro {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.attribute-syntax {
  margin-top: 2rem;
}

.attribute-syntax ul {
  list-style: none;
  margin-top: 1rem;
}

.attribute-syntax li {
  padding: 0.5rem 0;
  position: relative;
  padding-left: 1.5rem;
  color: var(--light-3);
}

.attribute-syntax li:before {
  content: "•";
  color: var(--primary);
  position: absolute;
  left: 0;
  font-weight: bold;
}

.common-attributes {
  margin-top: 2rem;
}

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

.attribute-item {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-md);
  padding: 1.5rem;
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition-normal);
}

.attribute-item:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
}

.attribute-item h4 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--light-1);
}

.attribute-item p {
  color: var(--light-3);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.attribute-item code {
  background: rgba(255,255,255,0.1);
  padding: 0.5rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--primary-light);
  display: block;
  text-align: center;
}

/* Demo Explanation */
.demo-explanation {
  margin-top: 2rem;
}

.concepts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.concept-point {
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-md);
  padding: 1.5rem;
  text-align: center;
  border: 1px solid rgba(255,255,255,0.1);
}

.concept-point h4 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--light-1);
}

.concept-point p {
  color: var(--light-3);
  font-size: 0.9rem;
}

/* Code Demonstration */
.code-demonstration {
  margin-top: 2rem;
  background: rgba(255,255,255,0.05);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255,255,255,0.1);
}

.code-demonstration h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  color: var(--light-1);
  text-align: center;
}

/* Responsive Design for Video 2 */
@media (max-width: 768px) {
  .syntax-comparison {
    grid-template-columns: 1fr;
  }
  
  .anatomy-visual {
    gap: 0.5rem;
  }
  
  .content {
    margin-left: 1rem;
  }
  
  .types-grid {
    grid-template-columns: 1fr;
  }
  
  .void-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .attributes-grid {
    grid-template-columns: 1fr;
  }
  
  .concepts-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .void-grid {
    grid-template-columns: 1fr;
  }
  
  .anatomy-part {
    padding: 1rem;
  }
}