:root {
  --bg-primary: #09090b;
  --bg-secondary: #0f0f12;
  --bg-tertiary: #18181b;
  --bg-elevated: #1f1f23;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --accent: #22c55e;
  --accent-hover: #16a34a;
  --accent-subtle: rgba(34, 197, 94, 0.1);
  --accent-glow: rgba(34, 197, 94, 0.25);
  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.15);
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.6);
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

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

/* Custom scrollbars */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb {
  background: var(--bg-elevated);
  border-radius: 5px;
  border: 2px solid var(--bg-secondary);
  transition: background var(--transition-fast);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

::-webkit-scrollbar-thumb:active {
  background: var(--accent);
}

::-webkit-scrollbar-corner {
  background: var(--bg-secondary);
}

/* Firefox scrollbar */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--bg-elevated) var(--bg-secondary);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9, 9, 11, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1.125rem;
}

.nav-logo {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  box-shadow: 0 0 20px var(--accent-glow);
}

.nav-logo img {
  position: relative;
  z-index: 1;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-links a:hover {
  color: var(--text-primary);
}

.nav-mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 1px;
  transition: var(--transition-fast);
}

.nav-mobile-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-mobile-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-mobile-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

.nav-mobile-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px 24px;
  flex-direction: column;
  gap: 8px;
}

.nav-mobile-menu.active {
  display: flex;
}

.nav-mobile-menu a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 1rem;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
  transition: color var(--transition-fast);
}

.nav-mobile-menu a:last-of-type {
  border-bottom: none;
}

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

.nav-mobile-menu .btn {
  margin-top: 8px;
  width: 100%;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  font-family: inherit;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent);
  color: #000;
  box-shadow: 0 0 0 0 var(--accent-glow);
}

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 0 20px 0 var(--accent-glow);
  transform: translateY(-1px);
}

.btn-primary svg {
  transition: transform var(--transition-fast);
}

.btn-primary:hover svg {
  transform: translateX(4px);
}

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

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

.btn-lg {
  padding: 14px 28px;
  font-size: 1rem;
  border-radius: var(--radius-lg);
}

.btn-block {
  width: 100%;
}

/* Hero Section */
.hero {
  min-height: calc(100vh - 64px);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  padding: 80px 24px;
  max-width: 1200px;
  margin: 0 auto;
}

.hero-content {
  max-width: 560px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--accent-subtle);
  border: 1px solid rgba(34, 197, 94, 0.2);
  border-radius: 100px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--accent);
  margin-bottom: 24px;
  animation: badge-glow 2s ease-in-out infinite;
}

.hero-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
  box-shadow: 0 0 8px var(--accent);
}

@keyframes badge-glow {
  0%, 100% { box-shadow: 0 0 0 0 transparent; }
  50% { box-shadow: 0 0 20px -5px var(--accent-glow); }
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(0.8); }
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.highlight-text {
  background: linear-gradient(135deg, var(--accent) 0%, #4ade80 50%, var(--accent) 100%);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradient-shift 3s ease-in-out infinite;
  position: relative;
}

.highlight-text::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0.6;
}

@keyframes gradient-shift {
  0%, 100% { background-position: 0% center; }
  50% { background-position: 100% center; }
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 40px;
}

.hero-cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Code Window */
.code-window {
  width: 100%;
  max-width: 520px;
  background: var(--bg-secondary);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  box-shadow:
    var(--shadow-lg),
    0 0 60px -20px var(--accent-glow),
    inset 0 1px 0 rgba(255, 255, 255, 0.05);
  overflow: hidden;
  position: relative;
}

.code-window::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(34, 197, 94, 0.3), transparent);
}

.code-window-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 18px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
}

.code-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg-elevated);
}

.code-dot:first-child { background: #ff5f56; }
.code-dot:nth-child(2) { background: #ffbd2e; }
.code-dot:nth-child(3) { background: #27ca40; }

.code-filename {
  margin-left: auto;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', 'Fira Code', 'SF Mono', Consolas, monospace;
}

.code-content {
  padding: 16px 20px;
  overflow-x: auto;
  font-family: 'JetBrains Mono', 'Fira Code', 'SF Mono', Consolas, monospace;
  font-size: 0.8125rem;
  line-height: 1.6;
  text-align: left;
}

.code-content .code-line {
  white-space: pre;
  padding: 2px 0;
}

.code-content .code-line:nth-child(n+3) {
  padding-left: 1.5em;
}

.code-comment { color: #6b737c; }
.code-label { color: #79c0ff; }
.code-instruction { color: #ff7b72; }
.code-register { color: #ffa657; }
.code-number { color: #a5d6ff; }
.code-string { color: #a5d6ff; }
.code-function { color: #d2a8ff; }

.code-cursor {
  display: inline-block;
  width: 2px;
  height: 1.1em;
  background: var(--accent);
  margin-left: 2px;
  animation: blink 1s step-end infinite;
  vertical-align: text-bottom;
}

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

/* Section Headers */
.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 64px;
}

.section-header h2 {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* How It Works - Visual Showcase */
.how-it-works {
  padding: 120px 0;
  background: var(--bg-primary);
}

.showcase-step {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 64px;
  align-items: center;
  padding: 80px 0;
  border-bottom: 1px solid var(--border);
}

.showcase-step:last-child {
  border-bottom: none;
}

.showcase-step.reverse {
  grid-template-columns: 1.4fr 1fr;
}

.showcase-step.reverse .showcase-content {
  order: 2;
}

.showcase-step.reverse .showcase-visual {
  order: 1;
}

.showcase-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.showcase-content h3 {
  font-size: 1.75rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.showcase-content p {
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 1.0625rem;
}

.showcase-visual {
  display: flex;
  justify-content: center;
}

/* Mock UI Components */
.mock-lesson,
.mock-debugger,
.mock-challenge,
.mock-memory-viewer {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  width: 100%;
  max-width: 480px;
  box-shadow: var(--shadow-lg);
  position: relative;
}


/* Mock Lesson */
.mock-lesson-header {
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
  font-size: 0.8125rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.mock-breadcrumb {
  color: var(--text-muted);
}

.mock-separator {
  color: var(--text-muted);
}

.mock-current {
  color: var(--text-primary);
}

.mock-lesson-content {
  padding: 24px;
}

.mock-lesson-content h4 {
  font-size: 1.125rem;
  margin-bottom: 12px;
}

.mock-lesson-content p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

.mock-lesson-content code {
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.8125rem;
  color: var(--accent);
}

.mock-lesson-content em {
  color: var(--text-primary);
  font-style: italic;
}

/* Mock Stack Diagram */
.mock-stack {
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  overflow: hidden;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.75rem;
}

.mock-stack-row {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 16px;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
}

.mock-stack-row:last-child {
  border-bottom: none;
}

.mock-stack-row.header {
  background: var(--bg-elevated);
  color: var(--text-muted);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.mock-stack-row.highlight {
  background: var(--accent-subtle);
}

.mock-addr {
  color: var(--text-muted);
}

.mock-val {
  color: var(--text-primary);
}

.mock-pointer {
  color: var(--accent);
  font-weight: 600;
}

/* Mock Debugger */
.mock-debugger-toolbar {
  padding: 10px 16px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 8px;
}

.mock-btn {
  padding: 6px 12px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-family: inherit;
  cursor: default;
}

.mock-debugger-panels {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.mock-code-panel {
  padding: 12px;
  border-right: 1px solid var(--border);
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.75rem;
}

.mock-code-line {
  padding: 4px 8px;
  border-radius: 4px;
  display: flex;
  gap: 12px;
}

.mock-code-line.active {
  background: var(--accent-subtle);
  border-left: 2px solid var(--accent);
}

.mock-addr-small {
  color: var(--text-muted);
  font-size: 0.6875rem;
}

.mock-instr {
  color: var(--text-primary);
}

.mock-registers {
  padding: 12px;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.6875rem;
}

.mock-reg {
  display: flex;
  justify-content: space-between;
  padding: 6px 8px;
  border-radius: 4px;
}

.mock-reg span:first-child {
  color: var(--text-muted);
}

.mock-reg span:last-child {
  color: var(--text-secondary);
}

.mock-reg.changed {
  background: rgba(251, 191, 36, 0.1);
}

.mock-reg.changed span:last-child {
  color: #fbbf24;
}

/* Mock Challenge */
.mock-challenge-header {
  padding: 16px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.mock-challenge-title {
  font-weight: 600;
  font-size: 0.9375rem;
}

.mock-difficulty {
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-subtle);
  padding: 4px 10px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.mock-challenge-desc {
  padding: 16px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
}

.mock-challenge-input {
  padding: 16px;
}

.mock-challenge-input label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.mock-input-row {
  display: flex;
  gap: 8px;
}

.mock-input-row input {
  flex: 1;
  padding: 10px 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.875rem;
}

.mock-submit {
  padding: 10px 16px;
  border-radius: var(--radius);
  border: none;
  font-size: 0.8125rem;
  font-weight: 500;
  font-family: inherit;
  cursor: default;
}

.mock-submit.success {
  background: var(--accent);
  color: #000;
}

.mock-success-msg {
  padding: 16px;
  background: var(--accent-subtle);
  border-top: 1px solid rgba(34, 197, 94, 0.2);
  font-size: 0.8125rem;
  color: var(--accent);
}

/* Features Section */
.features {
  padding: 120px 0;
  background: var(--bg-secondary);
}

.feature-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.feature-demo {
  display: flex;
  justify-content: center;
}

/* Mock Memory Viewer */
.mock-memory-viewer {
  max-width: 420px;
}

.mock-memory-header {
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8125rem;
}

.mock-memory-header span:first-child {
  font-weight: 500;
}

.mock-memory-addr {
  color: var(--text-muted);
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.75rem;
}

.mock-hex-dump {
  padding: 12px;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.75rem;
}

.mock-hex-row {
  display: grid;
  grid-template-columns: 70px 1fr 80px;
  gap: 16px;
  padding: 6px 8px;
  border-radius: 4px;
}

.mock-hex-row:hover {
  background: var(--bg-tertiary);
}

.mock-offset {
  color: var(--text-muted);
}

.mock-bytes {
  color: var(--text-primary);
  letter-spacing: 0.05em;
}

.mock-ascii {
  color: var(--accent);
}

/* Feature List */
.feature-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.feature-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  transition: transform var(--transition-base);
}

.feature-item:hover {
  transform: translateX(4px);
}

.feature-item-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-subtle);
  border-radius: var(--radius);
  color: var(--accent);
  flex-shrink: 0;
  transition: all var(--transition-base);
  position: relative;
}

.feature-item:hover .feature-item-icon {
  background: rgba(34, 197, 94, 0.2);
  box-shadow: 0 0 20px -5px var(--accent-glow);
}

.feature-item-content h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.feature-item-content p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Curriculum */
.curriculum {
  padding: 120px 0;
  background: var(--bg-primary);
}

.curriculum-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.curriculum-phase {
  background: var(--bg-secondary);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-base);
}

.curriculum-phase:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.curriculum-phase:hover .phase-number {
  opacity: 1;
}

.curriculum-phase:first-child {
  border-color: rgba(34, 197, 94, 0.3);
}

.curriculum-phase:first-child:hover {
  border-color: var(--accent);
  box-shadow:
    var(--shadow-lg),
    0 0 30px -10px var(--accent-glow);
}

.phase-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.phase-number {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent) 0%, #4ade80 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0.7;
}

.phase-status {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-subtle);
  padding: 4px 10px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.phase-status.soon {
  color: var(--text-muted);
  background: var(--bg-tertiary);
}

.curriculum-phase.coming-soon {
  opacity: 0.6;
}

.curriculum-phase.coming-soon:hover {
  opacity: 0.8;
}

.curriculum-phase h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.phase-description {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.6;
}

.phase-topics {
  list-style: none;
  flex: 1;
  margin-bottom: 20px;
}

.phase-topics li {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.phase-topics li::before {
  content: "";
  width: 4px;
  height: 4px;
  background: var(--accent);
  border-radius: 50%;
  margin-top: 7px;
  flex-shrink: 0;
}

.phase-topics li:last-child {
  border-bottom: none;
}

.phase-meta {
  display: flex;
  gap: 16px;
  font-size: 0.75rem;
  color: var(--text-muted);
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

/* Pricing */
.pricing {
  padding: 120px 0;
  background: var(--bg-primary);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 1000px;
  margin: 0 auto;
}

.pricing-card {
  background: var(--bg-secondary);
  border-radius: var(--radius-xl);
  border: 1px solid var(--border);
  padding: 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-base);
}

.pricing-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.pricing-card.featured:hover {
  transform: scale(1.04);
}

.pricing-card.featured {
  border-color: var(--accent);
  background: linear-gradient(180deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
  box-shadow:
    var(--shadow-lg),
    0 0 40px -10px var(--accent-glow),
    inset 0 1px 0 rgba(255, 255, 255, 0.05);
  transform: scale(1.02);
}

.pricing-card.featured::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #000;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 100px;
  white-space: nowrap;
}

.pricing-header {
  margin-bottom: 24px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.pricing-header h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.price {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1;
  margin-bottom: 8px;
}

.price span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
}

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

.pricing-features {
  list-style: none;
  flex: 1;
  margin-bottom: 24px;
}

.pricing-features li {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  padding: 10px 0;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.pricing-features li::before {
  content: "\2713";
  width: 18px;
  height: 18px;
  background: var(--accent-subtle);
  border-radius: 50%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.625rem;
  color: var(--accent);
  margin-top: 2px;
}

/* CTA Section */
.cta {
  padding: 120px 0;
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
  position: relative;
  overflow: hidden;
}

.cta::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  opacity: 0.3;
  pointer-events: none;
  animation: cta-pulse 4s ease-in-out infinite;
}

@keyframes cta-pulse {
  0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.2; }
  50% { transform: translate(-50%, -50%) scale(1.1); opacity: 0.35; }
}

.cta-content {
  text-align: center;
  max-width: 560px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.cta h2 {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.cta p {
  color: var(--text-secondary);
  font-size: 1.125rem;
  margin-bottom: 32px;
  line-height: 1.7;
}

.email-form {
  display: flex;
  gap: 12px;
  max-width: 440px;
  margin: 0 auto 16px;
}

.email-form input {
  flex: 1;
  padding: 14px 18px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 1rem;
  font-family: inherit;
  transition: all var(--transition-fast);
}

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

.email-form input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-subtle);
}

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

/* Footer */
.footer {
  padding: 64px 0 32px;
  border-top: 1px solid var(--border);
}

.footer-main {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 64px;
  margin-bottom: 48px;
}

.footer-brand {
  max-width: 280px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1rem;
  margin-bottom: 12px;
}

.footer-logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  box-shadow: 0 0 16px var(--accent-glow);
}

.footer-logo-icon img {
  position: relative;
  z-index: 1;
}

.footer-tagline {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.powered-by {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.powered-by-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.powered-by-link img {
  border-radius: 4px;
}

.footer-links-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-column h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
}

.footer-column a {
  display: block;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 6px 0;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

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

.footer-legal {
  display: flex;
  gap: 24px;
}

.footer-legal a {
  font-size: 0.875rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-legal a:hover {
  color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 1024px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 48px;
    text-align: center;
    padding: 60px 24px;
    min-height: auto;
  }

  .hero-content {
    max-width: 600px;
    margin: 0 auto;
  }

  .hero-cta {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .showcase-step,
  .showcase-step.reverse {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .showcase-step.reverse .showcase-content,
  .showcase-step.reverse .showcase-visual {
    order: unset;
  }

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

  .feature-showcase {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .footer-main {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .footer-brand {
    max-width: none;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .nav-mobile-toggle {
    display: flex;
  }

  .hero {
    padding: 40px 24px;
  }

  .hero h1 {
    font-size: 2.5rem;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .hero-cta .btn {
    width: 100%;
    max-width: 280px;
  }

  .how-it-works,
  .features,
  .curriculum,
  .pricing,
  .cta {
    padding: 80px 0;
  }

  .section-header {
    margin-bottom: 48px;
  }

  .section-header h2,
  .cta h2 {
    font-size: 2rem;
  }

  .showcase-step {
    padding: 48px 0;
  }

  .showcase-content h3 {
    font-size: 1.5rem;
  }

  .showcase-visual {
    width: 100%;
  }

  .mock-lesson,
  .mock-debugger,
  .mock-challenge,
  .mock-memory-viewer {
    max-width: 100%;
  }

  .mock-debugger-panels {
    grid-template-columns: 1fr;
  }

  .mock-code-panel {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .mock-registers {
    padding: 12px 8px;
  }

  .mock-reg span:last-child {
    font-size: 0.5625rem;
  }

  .feature-list {
    gap: 20px;
  }

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

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

  .email-form {
    flex-direction: column;
  }

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

  .footer-bottom {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 32px 16px;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero-subtitle {
    font-size: 0.9375rem;
  }

  .hero-badge {
    font-size: 0.75rem;
    padding: 5px 12px;
  }

  .how-it-works,
  .features,
  .curriculum,
  .pricing,
  .cta {
    padding: 60px 0;
  }

  .section-header h2,
  .cta h2 {
    font-size: 1.5rem;
  }

  .section-subtitle {
    font-size: 1rem;
  }

  .showcase-step {
    padding: 32px 0;
  }

  .showcase-content h3 {
    font-size: 1.25rem;
  }

  .showcase-content p {
    font-size: 0.9375rem;
  }

  .code-window,
  .mock-lesson,
  .mock-debugger,
  .mock-challenge,
  .mock-memory-viewer {
    margin: 0 -8px;
    border-radius: var(--radius);
  }

  .mock-lesson-content {
    padding: 16px;
  }

  .mock-lesson-content h4 {
    font-size: 1rem;
  }

  .mock-lesson-content p {
    font-size: 0.8125rem;
  }

  .mock-stack-row {
    padding: 6px 8px;
    gap: 8px;
  }

  .mock-challenge-input {
    padding: 12px;
  }

  .mock-input-row {
    flex-direction: column;
  }

  .mock-submit {
    width: 100%;
  }

  .feature-item {
    gap: 12px;
  }

  .feature-item-icon {
    width: 36px;
    height: 36px;
  }

  .feature-item-content h4 {
    font-size: 0.9375rem;
  }

  .feature-item-content p {
    font-size: 0.8125rem;
  }

  .pricing-card,
  .curriculum-phase {
    padding: 20px;
  }

  .price {
    font-size: 2.5rem;
  }

  .mock-hex-row {
    grid-template-columns: 60px 1fr;
    gap: 8px;
    font-size: 0.6875rem;
  }

  .mock-ascii {
    display: none;
  }

  .footer {
    padding: 48px 0 24px;
  }

  .footer-links-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

/* Auth Modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}

.modal.active {
  opacity: 1;
  visibility: visible;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(4px);
}

.modal-container {
  position: relative;
  width: 100%;
  max-width: 400px;
  max-height: calc(100vh - 48px);
  overflow-y: auto;
}

.modal-content {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px;
  box-shadow: var(--shadow-lg);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius);
  transition: all var(--transition-fast);
}

.modal-close:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.auth-header {
  text-align: center;
  margin-bottom: 24px;
}

.auth-header h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.auth-header p {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.auth-tabs {
  display: flex;
  gap: 4px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  padding: 4px;
  margin-bottom: 24px;
}

.auth-tab {
  flex: 1;
  padding: 10px 16px;
  background: transparent;
  border: none;
  border-radius: calc(var(--radius) - 2px);
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.auth-tab:hover {
  color: var(--text-primary);
}

.auth-tab.active {
  background: var(--bg-elevated);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group input {
  padding: 12px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.9375rem;
  font-family: inherit;
  transition: all var(--transition-fast);
}

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

.form-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-subtle);
}

.auth-error {
  padding: 12px;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: var(--radius);
  color: #ef4444;
  font-size: 0.8125rem;
}

.auth-divider {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 24px 0;
}

.auth-divider::before,
.auth-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

.auth-divider span {
  font-size: 0.75rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.oauth-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.btn-oauth {
  flex: 1;
  padding: 12px 20px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  color: var(--text-primary);
  font-size: 0.9375rem;
  font-weight: 500;
}

.btn-oauth:hover {
  background: var(--bg-elevated);
  border-color: var(--border-hover);
}

.btn-loading {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-loading[hidden] {
  display: none;
}

.spinner {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* Scroll Animations */
.fade-in-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-up.visible {
  opacity: 1;
  transform: translateY(0);
}

.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }

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

  html {
    scroll-behavior: auto;
  }

  .fade-in-up {
    opacity: 1;
    transform: none;
  }
}