:root {
  --bg-primary: #0a0d14;
  --bg-secondary: #111726;
  --bg-card: rgba(18, 24, 38, 0.75);
  --bg-card-hover: rgba(26, 36, 58, 0.85);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(56, 189, 248, 0.25);
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --accent-cyan: #38bdf8;
  --accent-blue: #2563eb;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --code-bg: #0d1117;
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --shadow-lg: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --shadow-cyan: 0 0 25px -5px rgba(56, 189, 248, 0.3);
}

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

html {
  scroll-behavior: smooth;
  color-scheme: dark;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(37, 99, 235, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 85% 65%, rgba(56, 189, 248, 0.1) 0%, transparent 45%);
  background-attachment: fixed;
}

/* Header & Nav */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 13, 20, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  color: var(--text-main);
}

.brand-img {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  object-fit: cover;
  border: 1px solid var(--border-glow);
  box-shadow: 0 0 10px rgba(56, 189, 248, 0.25);
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-badge {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-cyan);
  padding: 0.2rem 0.5rem;
  border-radius: 9999px;
  border: 1px solid rgba(56, 189, 248, 0.3);
  font-weight: 600;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s ease, transform 0.2s ease;
}

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

.btn-cta-nav {
  background: linear-gradient(135deg, #0284c7, #2563eb);
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid rgba(255, 255, 255, 0.15);
  transition: all 0.25s ease;
}

.btn-cta-nav:hover {
  box-shadow: var(--shadow-cyan);
  transform: translateY(-1px);
}

/* Layout Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Hero Section */
.hero {
  padding: 6rem 0 4rem;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.25);
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  margin-bottom: 1.25rem;
}

.hero-tag .dot {
  width: 7px;
  height: 7px;
  background-color: var(--accent-emerald);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-emerald);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { opacity: 0.4; }
  50% { opacity: 1; }
  100% { opacity: 0.4; }
}

.hero-title {
  font-size: 3.2rem;
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
}

.hero-gradient {
  background: linear-gradient(135deg, #ffffff 40%, var(--accent-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 2rem;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  color: #fff;
  padding: 0.85rem 1.6rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: var(--shadow-cyan);
  transition: all 0.25s ease;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 35px -5px rgba(56, 189, 248, 0.5);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.85rem 1.6rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.2s ease;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
}

/* Terminal Card in Hero */
.terminal-window {
  background: var(--code-bg);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 12px;
  box-shadow: var(--shadow-lg), 0 0 40px -10px rgba(14, 165, 233, 0.2);
  overflow: hidden;
}

.terminal-header {
  background: rgba(255, 255, 255, 0.04);
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
}

.terminal-buttons {
  display: flex;
  gap: 0.4rem;
}

.terminal-btn {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.terminal-btn.red { background: #ef4444; }
.terminal-btn.yellow { background: #f59e0b; }
.terminal-btn.green { background: #10b981; }

.terminal-title {
  margin-left: auto;
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.terminal-body {
  padding: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #e2e8f0;
  line-height: 1.7;
}

.terminal-prompt {
  color: var(--accent-cyan);
}

.terminal-success {
  color: var(--accent-emerald);
}

.terminal-highlight {
  color: var(--accent-amber);
}

/* Section Common */
.section {
  padding: 5rem 0;
  border-top: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.5rem;
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 2.3rem;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* Pillars Cards */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.card {
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--border-glow);
  box-shadow: 0 12px 30px -10px rgba(0, 0, 0, 0.6), var(--shadow-cyan);
  background: var(--bg-card-hover);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 1.25rem;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.card-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Architecture Comparison Table */
.table-container {
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: 12px;
  background: var(--bg-card);
  box-shadow: var(--shadow-lg);
}

.tech-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.tech-table th, .tech-table td {
  padding: 1.2rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.tech-table th {
  background: rgba(255, 255, 255, 0.03);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.tech-table tr:hover td {
  background: rgba(56, 189, 248, 0.03);
}

.badge-hurd {
  color: var(--accent-cyan);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

/* Roadmap Grid */
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.roadmap-phase {
  border: 1px solid var(--border-color);
  border-radius: 12px;
  background: var(--bg-card);
  padding: 1.75rem;
  position: relative;
}

.phase-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-cyan);
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.phase-title {
  font-size: 1.15rem;
  margin-bottom: 1rem;
}

.phase-items {
  list-style: none;
}

.phase-item {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
}

.phase-item.done {
  color: var(--text-main);
}

.phase-item.done .icon-check {
  color: var(--accent-emerald);
}

/* Lab & Interactive Shell */
.lab-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: center;
}

.code-block {
  background: var(--code-bg);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  overflow-x: auto;
  position: relative;
}

.copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  background: rgba(255, 255, 255, 0.1);
  border: none;
  color: var(--text-muted);
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.copy-btn:hover {
  background: var(--accent-cyan);
  color: #000;
}

/* Footer */
.footer {
  background: #07090e;
  border-top: 1px solid var(--border-color);
  padding: 3.5rem 0 2rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}

.footer-brand-desc {
  margin-top: 0.75rem;
  line-height: 1.6;
  max-width: 380px;
}

.footer-col h4 {
  color: var(--text-main);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--accent-cyan);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.8rem;
}

/* Responsive */
@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    padding-top: 3rem;
  }
  .hero-tag {
    margin-left: auto;
    margin-right: auto;
  }
  .hero-actions {
    justify-content: center;
  }
  .lab-box {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}