:root {
  --color-bg: #0a0e27;
  --color-bg-secondary: #1a1f3a;
  --color-cyan: #00FFFF;
  --color-magenta: #FF00FF;
  --color-lime: #00FF41;
  --color-text: #e0e0e0;
  --color-text-secondary: #a0a0a0;
  --accent-glow: 0 0 20px rgba(0, 255, 255, 0.3);
}

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

body {
  font-family: 'Monaco', 'Courier New', monospace;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

.scanlines {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  background: repeating-linear-gradient(
    0deg,
    rgba(255, 255, 255, 0.04) 0px,
    rgba(255, 255, 255, 0.04) 1px,
    transparent 1px,
    transparent 3px
  );
  opacity: 0.35;
  z-index: 0;
}

.header,
main,
.footer {
  position: relative;
  z-index: 1;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* HEADER */
.header {
  background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-secondary) 100%);
  border-bottom: 2px solid var(--color-cyan);
  padding: 20px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 0 20px rgba(0, 255, 255, 0.2);
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 40px;
}

.logo-section {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  width: 50px;
  height: 50px;
  filter: drop-shadow(0 0 10px rgba(0, 255, 255, 0.5));
}

.title {
  font-size: 24px;
  font-weight: bold;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-magenta));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 0 20px rgba(0, 255, 255, 0.3);
}

.nav-tabs {
  display: flex;
  gap: 30px;
  flex-wrap: wrap;
}

.nav-link {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  padding: 8px 12px;
  border-bottom: 2px solid transparent;
  transition: all 0.3s ease;
  cursor: pointer;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-cyan);
  border-bottom-color: var(--color-cyan);
  text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
}

/* TABS */
.tab-content {
  display: none;
  animation: fadeIn 0.5s ease-in;
}

.tab-content.active {
  display: block;
}

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

/* HERO */
.hero {
  padding: 80px 0;
  background: linear-gradient(135deg, rgba(0, 255, 255, 0.05) 0%, rgba(255, 0, 255, 0.05) 100%);
  border-bottom: 1px solid rgba(0, 255, 255, 0.2);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 50%, rgba(0, 255, 255, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero-title {
  font-size: 48px;
  font-weight: bold;
  margin-bottom: 20px;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-magenta), var(--color-lime));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 20px;
  color: var(--color-text-secondary);
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 12px 30px;
  font-size: 16px;
  font-weight: 600;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.3s ease;
  font-family: inherit;
}

.btn-primary {
  background: linear-gradient(90deg, var(--color-cyan), var(--color-magenta));
  color: var(--color-bg);
  box-shadow: 0 0 20px rgba(0, 255, 255, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 40px rgba(0, 255, 255, 0.6);
}

.btn-secondary {
  background: transparent;
  color: var(--color-cyan);
  border: 2px solid var(--color-cyan);
  box-shadow: inset 0 0 20px rgba(0, 255, 255, 0.1);
}

.btn-secondary:hover {
  background: rgba(0, 255, 255, 0.1);
  box-shadow: 0 0 20px rgba(0, 255, 255, 0.4);
}

/* FEATURES */
.features {
  padding: 80px 0;
  background: var(--color-bg);
}

.features h3 {
  font-size: 32px;
  margin-bottom: 60px;
  text-align: center;
  color: var(--color-cyan);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.feature-card {
  background: linear-gradient(135deg, var(--color-bg-secondary) 0%, rgba(0, 255, 255, 0.05) 100%);
  border: 1px solid rgba(0, 255, 255, 0.2);
  padding: 30px;
  border-radius: 8px;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 255, 255, 0.1), transparent);
  transition: left 0.5s ease;
}

.feature-card:hover {
  border-color: var(--color-cyan);
  box-shadow: 0 0 20px rgba(0, 255, 255, 0.3);
  transform: translateY(-5px);
}

.feature-card:hover::before {
  left: 100%;
}

.feature-icon {
  font-size: 32px;
  font-weight: bold;
  color: var(--color-magenta);
  margin-bottom: 15px;
}

.feature-card h4 {
  font-size: 18px;
  margin-bottom: 12px;
  color: var(--color-cyan);
}

.feature-card p {
  color: var(--color-text-secondary);
  font-size: 14px;
}

/* QUICK START */
.quick-start {
  padding: 80px 0;
  background: linear-gradient(135deg, rgba(255, 0, 255, 0.05) 0%, rgba(0, 255, 255, 0.05) 100%);
  border-top: 1px solid rgba(0, 255, 255, 0.2);
}

.quick-start h3 {
  font-size: 32px;
  margin-bottom: 60px;
  text-align: center;
  color: var(--color-cyan);
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 40px;
}

.step {
  display: flex;
  gap: 20px;
}

.step-number {
  flex-shrink: 0;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--color-cyan), var(--color-magenta));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  color: var(--color-bg);
  font-size: 20px;
}

.step-content h4 {
  margin-bottom: 12px;
  color: var(--color-cyan);
}

.code-block {
  background: var(--color-bg-secondary);
  border: 1px solid rgba(0, 255, 255, 0.2);
  padding: 12px 16px;
  border-radius: 4px;
  font-family: 'Monaco', monospace;
  font-size: 13px;
  position: relative;
  margin-top: 8px;
}

.code-block code {
  color: var(--color-lime);
  word-break: break-all;
}

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  background: var(--color-cyan);
  color: var(--color-bg);
  border: none;
  padding: 4px 8px;
  border-radius: 3px;
  font-size: 12px;
  cursor: pointer;
  opacity: 0.7;
  transition: opacity 0.3s ease;
}

.copy-btn:hover {
  opacity: 1;
}

/* DOCS CONTENT */
.docs-content,
.practices-content,
.reference-content,
.examples-grid {
  margin-top: 40px;
}

.docs-content h3,
.practices-content h3,
.reference-content h3,
.practices-content h4 {
  color: var(--color-cyan);
  margin-top: 30px;
  margin-bottom: 15px;
}

.docs-content h4,
.reference-content h4 {
  color: var(--color-magenta);
  margin-top: 20px;
  margin-bottom: 12px;
}

.docs-content h5,
.reference-content h5 {
  color: var(--color-lime);
  margin-top: 15px;
  margin-bottom: 10px;
}

.docs-content ul,
.reference-content ul {
  margin-left: 20px;
  margin-bottom: 15px;
}

.docs-content li,
.reference-content li {
  margin-bottom: 8px;
  color: var(--color-text-secondary);
}

.params-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  border: 1px solid rgba(0, 255, 255, 0.2);
}

.params-table thead {
  background: linear-gradient(90deg, rgba(0, 255, 255, 0.1), rgba(255, 0, 255, 0.1));
}

.params-table th {
  padding: 12px;
  text-align: left;
  color: var(--color-cyan);
  font-weight: 600;
  border-bottom: 1px solid rgba(0, 255, 255, 0.2);
}

.params-table td {
  padding: 12px;
  border-bottom: 1px solid rgba(0, 255, 255, 0.1);
  color: var(--color-text-secondary);
}

.params-table tr:hover {
  background: rgba(0, 255, 255, 0.05);
}

/* CURRICULUM STAGES */
.curriculum-stages {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 25px;
  margin-top: 40px;
}

.stage-card {
  background: linear-gradient(135deg, var(--color-bg-secondary) 0%, rgba(0, 255, 255, 0.05) 100%);
  border: 2px solid rgba(0, 255, 255, 0.2);
  border-radius: 8px;
  padding: 30px;
  transition: all 0.3s ease;
  position: relative;
}

.stage-card.stage-1 { border-color: #00FF41; }
.stage-card.stage-2 { border-color: var(--color-cyan); }
.stage-card.stage-3 { border-color: var(--color-magenta); }
.stage-card.stage-4 { border-color: #FF6B00; }

.stage-number {
  display: inline-block;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-magenta));
  color: var(--color-bg);
  padding: 4px 12px;
  border-radius: 12px;
  font-weight: bold;
  margin-bottom: 12px;
  font-size: 12px;
}

.stage-card h3 {
  color: var(--color-cyan);
  margin-bottom: 15px;
}

.stage-params {
  background: rgba(0, 0, 0, 0.3);
  padding: 12px;
  border-radius: 4px;
  margin: 15px 0;
}

.stage-params ul {
  list-style: none;
  margin: 0;
}

.stage-params li {
  color: var(--color-text-secondary);
  font-size: 13px;
  margin: 4px 0;
}

.stage-desc, .stage-reward, .stage-time {
  color: var(--color-text-secondary);
  font-size: 13px;
  margin: 8px 0;
}

.stage-reward {
  color: var(--color-lime);
  font-weight: 600;
}

/* COLLAPSIBLE */
.collapsible-section {
  margin-bottom: 20px;
}

.collapsible-header {
  background: linear-gradient(90deg, rgba(0, 255, 255, 0.1), rgba(255, 0, 255, 0.1));
  border: 1px solid rgba(0, 255, 255, 0.2);
  padding: 15px;
  cursor: pointer;
  font-size: 16px;
  color: var(--color-cyan);
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.3s ease;
}

.collapsible-header:hover {
  background: linear-gradient(90deg, rgba(0, 255, 255, 0.2), rgba(255, 0, 255, 0.2));
  box-shadow: 0 0 10px rgba(0, 255, 255, 0.2);
}

.collapsible-body {
  display: none;
  background: var(--color-bg-secondary);
  border: 1px solid rgba(0, 255, 255, 0.1);
  border-top: none;
  padding: 20px;
  color: var(--color-text-secondary);
}

.collapsible-body.active {
  display: block;
}

.mistake {
  background: rgba(255, 107, 0, 0.1);
  border-left: 3px solid #FF6B00;
  padding: 15px;
  margin-bottom: 15px;
  border-radius: 4px;
}

.mistake h4 {
  color: #FF6B00;
  margin-bottom: 8px;
}

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

/* EXAMPLES */
.examples-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.example-card {
  background: linear-gradient(135deg, var(--color-bg-secondary) 0%, rgba(0, 255, 255, 0.05) 100%);
  border: 1px solid rgba(0, 255, 255, 0.2);
  padding: 25px;
  border-radius: 8px;
  transition: all 0.3s ease;
}

.example-card:hover {
  border-color: var(--color-cyan);
  box-shadow: 0 0 20px rgba(0, 255, 255, 0.2);
  transform: translateY(-3px);
}

.example-card h3 {
  color: var(--color-cyan);
  margin-bottom: 15px;
}

.example-card ul {
  list-style: none;
  margin: 15px 0;
}

.example-card li {
  color: var(--color-text-secondary);
  font-size: 13px;
  padding: 4px 0;
}

.example-card p {
  color: var(--color-text-secondary);
  font-size: 13px;
  margin: 8px 0;
}

/* SECTION INTRO */
.section-intro {
  text-align: center;
  color: var(--color-text-secondary);
  font-size: 16px;
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* MAIN SECTIONS */
main section {
  padding: 60px 0;
}

main section > .container > h2 {
  font-size: 36px;
  margin-bottom: 40px;
  color: var(--color-cyan);
}

/* FOOTER */
.footer {
  background: linear-gradient(135deg, var(--color-bg-secondary) 0%, var(--color-bg) 100%);
  border-top: 2px solid var(--color-cyan);
  padding: 40px 0;
  text-align: center;
  color: var(--color-text-secondary);
  margin-top: 60px;
}

.footer a {
  color: var(--color-cyan);
  text-decoration: none;
  transition: all 0.3s ease;
}

.footer a:hover {
  text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
}

/* RESPONSIVE */
@media (max-width: 768px) {
  .header .container {
    flex-direction: column;
    gap: 20px;
  }

  .nav-tabs {
    justify-content: center;
    gap: 15px;
  }

  .nav-link {
    font-size: 12px;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 16px;
  }

  main section {
    padding: 40px 0;
  }

  main section > .container > h2 {
    font-size: 24px;
  }
}