/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #ffffff;
  --color-text: #24292f;
  --color-text-muted: #57606a;
  --color-primary: #0969da;
  --color-primary-hover: #0550ae;
  --color-border: #d0d7de;
  --color-surface: #f6f8fa;
  --color-surface-hover: #eef1f5;
  --color-accent: #0969da;
  --color-hero-bg: #0d1117;
  --color-hero-text: #f0f6fc;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
  --max-width: 1200px;
}

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

code,
pre {
  font-family: var(--font-mono);
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(8px);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-text);
  text-decoration: none;
}

.nav-brand:hover {
  text-decoration: none;
}

.nav-logo {
  color: var(--color-primary);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 0.25rem;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius);
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  transition: background 0.15s, color 0.15s;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
  background: var(--color-surface);
}

.external-icon {
  opacity: 0.5;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  flex-direction: column;
  gap: 4px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: transform 0.2s;
}

/* ===== Hero ===== */
.hero {
  background: var(--color-hero-bg);
  color: var(--color-hero-text);
  padding: 5rem 1.5rem;
  text-align: center;
}

.hero-inner {
  max-width: 680px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
}

.hero-tagline {
  font-size: 1.25rem;
  color: #8b949e;
  margin-bottom: 1.5rem;
}

.hero-features {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.feature-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border: 1px solid #30363d;
  border-radius: 999px;
  font-size: 0.8125rem;
  color: #8b949e;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.625rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: background 0.15s, transform 0.1s;
  text-decoration: none;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

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

.btn-primary:hover {
  background: var(--color-primary-hover);
}

.btn-secondary {
  background: #21262d;
  color: #c9d1d9;
  border: 1px solid #30363d;
}

.btn-secondary:hover {
  background: #30363d;
}

/* ===== Demo Terminal ===== */
.demo {
  padding: 0 1.5rem;
  margin-top: -2rem;
  position: relative;
  z-index: 10;
}

.demo-inner {
  max-width: 640px;
  margin: 0 auto;
}

.terminal-window {
  background: #0d1117;
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  border: 1px solid #30363d;
}

.terminal-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 12px 16px;
  background: #161b22;
}

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

.terminal-dot.red { background: #ff5f57; }
.terminal-dot.yellow { background: #febc2e; }
.terminal-dot.green { background: #28c840; }

.terminal-title {
  flex: 1;
  text-align: center;
  font-size: 0.75rem;
  color: #848d97;
  margin-right: 42px;
}

.terminal-body {
  padding: 1rem 1.25rem 1.25rem;
}

.terminal-body pre {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.7;
}

.terminal-body code {
  color: #c9d1d9;
}

.terminal-body .prompt {
  color: #7ee787;
}

.terminal-body .output {
  color: #8b949e;
}

/* ===== Features Section ===== */
.features-section {
  padding: 5rem 1.5rem;
}

.features-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.feature-card {
  padding: 1.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: box-shadow 0.2s, transform 0.15s;
}

.feature-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.feature-card h2 {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.feature-card p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* ===== Pipeline Section ===== */
.pipeline-section {
  padding: 4rem 1.5rem 5rem;
  background: var(--color-surface);
}

.pipeline-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.pipeline-inner h2 {
  text-align: center;
  font-size: 1.75rem;
  margin-bottom: 2.5rem;
}

.pipeline {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.pipeline-step {
  flex: 0 1 200px;
  text-align: center;
  padding: 1.25rem;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.875rem;
  margin-bottom: 0.75rem;
}

.pipeline-step h3 {
  font-size: 1rem;
  margin-bottom: 0.375rem;
}

.pipeline-step p {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.pipeline-arrow {
  display: flex;
  align-items: center;
  padding-top: 2rem;
  font-size: 1.5rem;
  color: var(--color-text-muted);
}

/* ===== Content Pages ===== */
.content-page {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.content-page .container {
  display: flex;
  gap: 2rem;
}

/* ===== Sidebar ===== */
.sidebar {
  flex: 0 0 220px;
  position: sticky;
  top: 72px;
  align-self: flex-start;
  max-height: calc(100vh - 88px);
  overflow-y: auto;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.sidebar-group h4 {
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
  padding: 0.25rem 0.5rem;
}

.sidebar-group h4 a {
  color: inherit;
  text-decoration: none;
}

.sidebar-group a,
a.sidebar-link {
  display: block;
  padding: 0.25rem 0.5rem 0.25rem 1rem;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  border-radius: 4px;
  text-decoration: none;
  transition: background 0.15s, color 0.15s;
}

.sidebar-group a:hover,
a.sidebar-link:hover,
.sidebar-group a.active,
a.sidebar-link.active {
  background: var(--color-surface);
  color: var(--color-text);
}

.sidebar-group a.active,
a.sidebar-link.active {
  font-weight: 600;
  color: var(--color-primary);
}

.sidebar-group {
  margin-bottom: 0.75rem;
}

/* ===== Article Content ===== */
.content {
  flex: 1;
  min-width: 0;
}

.content h1 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--color-border);
}

.content h2 {
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.content h3 {
  font-size: 1.25rem;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}

.content p {
  margin-bottom: 1rem;
}

.content ul,
.content ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

.content li {
  margin-bottom: 0.25rem;
}

.content pre {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem;
  overflow-x: auto;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  line-height: 1.6;
}

.content code {
  font-size: 0.875em;
}

.content p code,
.content li code {
  background: var(--color-surface);
  padding: 0.125rem 0.375rem;
  border-radius: 4px;
  font-size: 0.85em;
}

.content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1rem;
}

.content th,
.content td {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-border);
  text-align: left;
  font-size: 0.9375rem;
}

.content th {
  background: var(--color-surface);
  font-weight: 600;
}

.content blockquote {
  border-left: 4px solid var(--color-primary);
  padding: 0.5rem 1rem;
  margin-bottom: 1rem;
  color: var(--color-text-muted);
  background: var(--color-surface);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.last-updated {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.page-list {
  list-style: none;
  padding: 0;
}

.page-list li {
  margin-bottom: 1rem;
}

.page-list a {
  font-size: 1.125rem;
  font-weight: 500;
}

.page-list p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin: 0.25rem 0 0;
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 1.5rem;
  text-align: center;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.footer-inner a {
  color: var(--color-text-muted);
  text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.5rem;
  }

  .hero-tagline {
    font-size: 1.1rem;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 0.5rem;
  }

  .nav-links.open {
    display: flex;
  }

  .content-page .container {
    flex-direction: column;
  }

  .sidebar {
    position: static;
    flex: none;
    max-height: none;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 1rem;
    margin-bottom: 1rem;
  }

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

  .pipeline-arrow {
    transform: rotate(90deg);
    padding: 0;
  }
}