:root {
  --bg-primary: #0a0a0b;
  --bg-secondary: #111113;
  --bg-tertiary: #1a1a1d;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --accent: #22c55e;
  --accent-dim: #16a34a;
  --border: #27272a;
  --warning: #f59e0b;
}

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

body {
  font-family: 'Space Grotesk', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

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

/* Header */
header {
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--bg-primary);
  z-index: 100;
}

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

/* Offset for fixed header */
main {
  padding-top: 97px; /* header height (48px logo + 24px*2 padding + 1px border) */
}

/* Anchor offset for in-page links */
html {
  scroll-padding-top: 97px;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo:focus {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.logo-icon {
  width: 48px;
  height: 48px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-icon svg,
.logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

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

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}

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

.nav-links a:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.lang-switch {
  font-weight: 600;
  font-size: 0.85rem;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-tertiary);
  transition: all 0.2s;
}

.lang-switch:hover,
.lang-switch:focus {
  background: var(--border);
  color: var(--text-primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all 0.2s;
}

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

.btn-primary:hover,
.btn-primary:focus {
  background: var(--accent-dim);
}

.btn:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

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

.btn-secondary:hover,
.btn-secondary:focus {
  background: var(--border);
}

/* Hamburger Menu */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  border-radius: 4px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s ease;
}

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

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

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

.hamburger:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 300px;
    height: 100vh;
    background: var(--bg-secondary);
    flex-direction: column;
    justify-content: flex-start;
    padding: 80px 32px 32px;
    gap: 24px;
    border-left: 1px solid var(--border);
    transition: right 0.3s ease;
    z-index: 1000;
  }

  .nav-links.active {
    right: 0;
  }

  .nav-links a {
    font-size: 1.1rem;
  }

  .nav-links .btn {
    width: 100%;
    justify-content: center;
  }

  .nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 99;
  }

  .nav-overlay.active {
    display: block;
  }
}

/* Hero */
.hero {
  padding: 120px 0 100px;
  text-align: center;
}

.hero-label {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.85rem;
  color: var(--warning);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 24px;
  display: inline-block;
  padding: 6px 16px;
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.3);
  border-radius: 4px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 24px;
  letter-spacing: -0.02em;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 24px;
  line-height: 1.7;
}

.hero-definition {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 40px;
}

.hero-definition code {
  background: var(--bg-tertiary);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.9rem;
}

.hero-proof {
  font-size: 0.9rem;
  color: var(--accent);
  margin: 0 auto 40px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.hero-proof::before {
  content: "✓";
}

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

/* Sections */
.section {
  padding: 100px 0;
  border-top: 1px solid var(--border);
}

.section-label {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.8rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  margin-bottom: 32px;
  letter-spacing: -0.02em;
}

.section-text {
  color: var(--text-secondary);
  font-size: 1.1rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.section-text strong {
  color: var(--text-primary);
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin: 48px 0;
}

@media (max-width: 768px) {
  .stats-grid {
    grid-template-columns: 1fr;
  }
}

.stat-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 8px;
}

.stat-label {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.stat-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Principles Grid */
.principles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}

@media (max-width: 900px) {
  .principles-grid {
    grid-template-columns: 1fr;
  }
}

.principle-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px;
  position: relative;
}

.principle-number {
  position: absolute;
  top: -12px;
  left: 24px;
  background: var(--accent);
  color: #000;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 4px;
}

.principle-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  font-weight: 600;
}

.principle-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.principle-example {
  background: var(--bg-tertiary);
  border-radius: 8px;
  padding: 16px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.principle-example .good {
  color: var(--accent);
}

.principle-example .bad {
  color: #ef4444;
}

/* Solution Box */
.solution-box {
  background: var(--bg-secondary);
  border: 1px solid var(--accent);
  border-radius: 12px;
  padding: 40px;
}

.solution-box h3 {
  font-size: 1.5rem;
  margin-bottom: 16px;
}

.solution-box p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.solution-box ul {
  list-style: none;
}

.solution-box ul li {
  color: var(--text-secondary);
  font-size: 1.05rem;
  padding: 6px 0;
  display: flex;
  gap: 12px;
}

.solution-box ul li .bullet {
  color: var(--accent);
}

/* Workflow Grid */
.workflow-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

@media (max-width: 900px) {
  .workflow-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 500px) {
  .workflow-grid {
    grid-template-columns: 1fr;
  }
}

.workflow-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  position: relative;
}

.workflow-card::before {
  content: attr(data-step);
  position: absolute;
  top: -12px;
  left: 20px;
  background: var(--bg-primary);
  padding: 4px 12px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.75rem;
  color: var(--accent);
  border: 1px solid var(--border);
  border-radius: 4px;
}

.workflow-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  font-weight: 600;
}

.workflow-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 12px;
}

.workflow-principle {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.75rem;
  color: var(--accent);
  background: rgba(34, 197, 94, 0.1);
  padding: 4px 8px;
  border-radius: 4px;
  display: inline-block;
}

/* Clear Pattern */
.clear-pattern {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 32px;
  align-items: center;
  margin-top: 48px;
}

@media (max-width: 768px) {
  .clear-pattern {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

.clear-card {
  background: var(--bg-secondary);
  border-radius: 12px;
  padding: 24px;
}

.clear-card.before {
  border: 1px solid #ef4444;
}

.clear-card.after {
  border: 1px solid var(--accent);
}

.clear-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  font-weight: 600;
}

.clear-icon {
  font-size: 1.2rem;
}

.clear-icon.before {
  color: #ef4444;
}

.clear-icon.after {
  color: var(--accent);
}

.context-bar {
  height: 12px;
  background: var(--bg-tertiary);
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: 8px;
}

.context-fill {
  height: 100%;
  border-radius: 6px;
}

.context-fill.high {
  background: linear-gradient(90deg, #ef4444 0%, #f59e0b 70%, #ef4444 100%);
  width: 95%;
}

.context-fill.low {
  background: var(--accent);
  width: 15%;
}

.context-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.clear-arrow {
  font-size: 2rem;
  color: var(--accent);
}

@media (max-width: 768px) {
  .clear-arrow {
    transform: rotate(90deg);
    justify-self: center;
  }
}

/* Code Block */
.code-block {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  max-width: 700px;
}

.code-header {
  background: var(--bg-tertiary);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid var(--border);
}

.code-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.code-dot.red {
  background: #ef4444;
}
.code-dot.yellow {
  background: #eab308;
}
.code-dot.green {
  background: #22c55e;
}

.code-block pre {
  margin: 0;
  padding: 24px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.85rem;
  line-height: 1.8;
  overflow-x: auto;
}

.code-block code {
  font-family: inherit;
  color: var(--accent);
}

/* CTA Section */
.cta-section {
  padding: 120px 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.cta-section h2 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  margin-bottom: 24px;
  letter-spacing: -0.02em;
}

.cta-section p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto 40px;
}

/* Learn CTA Section */
.learn-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 768px) {
  .learn-grid {
    grid-template-columns: 1fr;
  }
}

.learn-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  text-decoration: none;
  transition: all 0.2s;
}

.learn-card:hover,
.learn-card:focus {
  border-color: var(--accent);
  transform: translateY(-4px);
}

.learn-card:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.learn-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.learn-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.learn-badge {
  display: inline-block;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.learn-badge.quick-start {
  color: #22c55e;
  background: rgba(34, 197, 94, 0.1);
}

.learn-badge.foundation {
  color: #3b82f6;
  background: rgba(59, 130, 246, 0.1);
}

.learn-badge.master {
  color: #a78bfa;
  background: rgba(167, 139, 250, 0.1);
}

/* Footer */
footer {
  padding: 40px 0;
  border-top: 1px solid var(--border);
}

footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

footer p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

footer a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}

footer a:hover,
footer a:focus {
  color: var(--text-primary);
}

footer a:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

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

/* Animations */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-label,
.hero h1,
.hero-subtitle,
.hero-definition,
.hero-proof,
.hero-cta {
  animation: fadeUp 0.6s ease-out forwards;
}

.hero-label {
  animation-delay: 0s;
}
.hero h1 {
  animation-delay: 0.1s;
}
.hero-subtitle {
  animation-delay: 0.2s;
}
.hero-definition {
  animation-delay: 0.3s;
}
.hero-proof {
  animation-delay: 0.35s;
}
.hero-cta {
  animation-delay: 0.4s;
}