/* ═══════════════════════════════════════════════════════════════════
   CSS Architecture — Design System Stylesheet
   Mirroring the three-layer token model documented in the site content
   ═══════════════════════════════════════════════════════════════════ */

/* ── Layer 1: Primitives (immutable raw values) ────────────────────── */
:root {
  --primitive-white: #ffffff;
  --primitive-slate-50: #f8fafc;
  --primitive-slate-100: #f1f5f9;
  --primitive-slate-200: #e2e8f0;
  --primitive-slate-300: #cbd5e1;
  --primitive-slate-400: #94a3b8;
  --primitive-slate-500: #64748b;
  --primitive-slate-600: #475569;
  --primitive-slate-700: #334155;
  --primitive-slate-800: #1e293b;
  --primitive-slate-900: #0f172a;
  --primitive-blue-50: #eff6ff;
  --primitive-blue-100: #dbeafe;
  --primitive-blue-200: #bfdbfe;
  --primitive-blue-400: #60a5fa;
  --primitive-blue-500: #3b82f6;
  --primitive-blue-600: #2563eb;
  --primitive-blue-700: #1d4ed8;
  --primitive-blue-800: #1e40af;
  --primitive-violet-50: #f5f3ff;
  --primitive-violet-100: #ede9fe;
  --primitive-violet-500: #8b5cf6;
  --primitive-violet-600: #7c3aed;
  --primitive-violet-700: #6d28d9;
  --primitive-emerald-50: #ecfdf5;
  --primitive-emerald-100: #d1fae5;
  --primitive-emerald-500: #10b981;
  --primitive-emerald-600: #059669;
  --primitive-emerald-700: #047857;
  --primitive-cyan-500: #06b6d4;
  --primitive-cyan-600: #0891b2;
  --primitive-amber-400: #fbbf24;
  --primitive-amber-500: #f59e0b;
  --primitive-orange-500: #f97316;
  --primitive-orange-600: #ea580c;
  --primitive-red-500: #ef4444;
  --primitive-green-600: #16a34a;
}

/* ── Layer 2: Semantic tokens (map primitives to intent) ───────────── */
:root {
  /* Backgrounds */
  --color-bg: var(--primitive-slate-50);
  --color-surface: var(--primitive-white);
  --color-surface-raised: var(--primitive-slate-50);
  --color-surface-overlay: var(--primitive-slate-100);

  /* Borders */
  --color-border: var(--primitive-slate-200);
  --color-border-light: var(--primitive-slate-100);
  --color-border-medium: var(--primitive-slate-300);

  /* Text */
  --color-text-primary: var(--primitive-slate-900);
  --color-text-secondary: var(--primitive-slate-600);
  --color-text-muted: var(--primitive-slate-400);
  --color-text-inverse: var(--primitive-white);

  /* Actions */
  --color-action: var(--primitive-blue-600);
  --color-action-hover: var(--primitive-blue-700);
  --color-action-active: var(--primitive-blue-800);
  --color-action-light: var(--primitive-blue-50);
  --color-action-light-hover: var(--primitive-blue-100);

  /* Pillar 1 — Theming & Dark Mode */
  --color-pillar-1: var(--primitive-violet-600);
  --color-pillar-1-hover: var(--primitive-violet-700);
  --color-pillar-1-light: var(--primitive-violet-50);
  --color-pillar-1-border: var(--primitive-violet-100);

  /* Pillar 2 — Token Fundamentals */
  --color-pillar-2: var(--primitive-blue-600);
  --color-pillar-2-hover: var(--primitive-blue-700);
  --color-pillar-2-light: var(--primitive-blue-50);
  --color-pillar-2-border: var(--primitive-blue-100);

  /* Pillar 3 — CI Pipelines */
  --color-pillar-3: var(--primitive-emerald-600);
  --color-pillar-3-hover: var(--primitive-emerald-700);
  --color-pillar-3-light: var(--primitive-emerald-50);
  --color-pillar-3-border: var(--primitive-emerald-100);

  /* Code */
  --color-code-bg: var(--primitive-slate-50);
  --color-code-border: var(--primitive-slate-200);
  --color-code-text: var(--primitive-slate-800);
  --color-inline-code-bg: var(--primitive-blue-50);
  --color-inline-code-text: var(--primitive-blue-800);

  /* Focus ring */
  --color-focus: var(--primitive-blue-500);

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;

  /* Type scale */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;

  /* Spacing (4px grid) */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Layout */
  --max-width: 1300px;
  --header-height: 4rem;
  --content-padding: var(--space-6);

  /* Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 8px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 12px 20px rgba(0,0,0,0.09), 0 4px 8px rgba(0,0,0,0.04);
  --shadow-xl: 0 24px 40px rgba(0,0,0,0.10), 0 8px 16px rgba(0,0,0,0.04);

  /* Transitions */
  --ease-fast: 120ms ease;
  --ease-base: 200ms ease;
  --ease-slow: 320ms ease;
}

/* ── Layer 3: Component tokens used below ──────────────────────────── */

/* ═══════════════════════════════════════════════════════════════════
   RESET & BASE
   ═══════════════════════════════════════════════════════════════════ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  /* Offset sticky header when jumping to anchors */
  scroll-padding-top: calc(var(--header-height) + 1.5rem);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg { display: block; max-width: 100%; }
a { color: var(--color-action); text-decoration: underline; text-decoration-color: transparent; transition: color var(--ease-fast), text-decoration-color var(--ease-fast); }
a:hover { color: var(--color-action-hover); text-decoration-color: currentColor; }
a:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 3px; border-radius: var(--radius-sm); }
button:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 3px; border-radius: var(--radius-sm); }

/* ═══════════════════════════════════════════════════════════════════
   LAYOUT
   ═══════════════════════════════════════════════════════════════════ */
.wrapper {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-inline: var(--content-padding);
}

main { flex: 1; }

/* ═══════════════════════════════════════════════════════════════════
   HEADER & NAV
   ═══════════════════════════════════════════════════════════════════ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  height: var(--header-height);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.site-header .wrapper {
  height: 100%;
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text-primary);
  font-weight: 700;
  font-size: var(--text-lg);
  letter-spacing: -0.02em;
  flex-shrink: 0;
  transition: opacity var(--ease-fast);
}
.site-logo:hover { opacity: 0.85; color: var(--color-text-primary); text-decoration-color: transparent; }
.site-logo img, .site-logo svg { width: 2rem; height: 2rem; border-radius: var(--radius-lg); }
.site-logo-name { display: none; }
@media (min-width: 480px) { .site-logo-name { display: inline; } }

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
  flex: 1;
}

.site-nav a {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  white-space: nowrap;
  transition: background var(--ease-fast), color var(--ease-fast);
}
.site-nav a:hover { background: var(--color-surface-overlay); color: var(--color-text-primary); }
.site-nav a.active { background: var(--color-action-light); color: var(--color-action); }

.nav-icon { width: 1rem; height: 1rem; flex-shrink: 0; }

/* Mobile nav */
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  margin-left: auto;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--color-text-secondary);
  transition: background var(--ease-fast);
}
.nav-toggle:hover { background: var(--color-surface-overlay); }
.nav-toggle svg { width: 1.25rem; height: 1.25rem; }

@media (max-width: 900px) {
  .nav-toggle { display: flex; }
  .site-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    padding: var(--space-3) var(--space-4);
    z-index: 199;
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: var(--space-3) var(--space-4); font-size: var(--text-base); border-radius: var(--radius-md); }
  .site-header { position: sticky; }
}

/* ═══════════════════════════════════════════════════════════════════
   HERO (home page)
   ═══════════════════════════════════════════════════════════════════ */
.hero {
  background: linear-gradient(135deg, var(--primitive-slate-900) 0%, var(--primitive-blue-800) 50%, var(--primitive-violet-700) 100%);
  color: var(--color-text-inverse);
  padding: var(--space-24) var(--space-6) var(--space-20);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 20% 40%, rgba(99,102,241,0.25) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 80% 60%, rgba(6,182,212,0.18) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner { position: relative; max-width: 900px; margin: 0 auto; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 500;
  margin-bottom: var(--space-6);
  backdrop-filter: blur(4px);
}

.hero-title {
  font-size: clamp(var(--text-3xl), 5vw, var(--text-6xl));
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-6);
}

.hero-title .accent-blue { color: var(--primitive-blue-400); }
.hero-title .accent-violet { color: var(--primitive-violet-500); }
.hero-title .accent-cyan { color: var(--primitive-cyan-500); }

.hero-desc {
  font-size: clamp(var(--text-base), 2vw, var(--text-xl));
  color: rgba(255,255,255,0.78);
  max-width: 680px;
  margin: 0 auto var(--space-10);
  line-height: 1.65;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-4);
}

.btn {
  --btn-bg: var(--color-action);
  --btn-bg-hover: var(--color-action-hover);
  --btn-text: var(--color-text-inverse);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  background: var(--btn-bg);
  color: var(--btn-text);
  font-size: var(--text-base);
  font-weight: 600;
  border: none;
  border-radius: var(--radius-xl);
  text-decoration: none;
  cursor: pointer;
  transition: background var(--ease-base), transform var(--ease-fast), box-shadow var(--ease-base);
  box-shadow: var(--shadow-md);
}
.btn:hover {
  background: var(--btn-bg-hover);
  color: var(--btn-text);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
  text-decoration-color: transparent;
}
.btn:active { transform: translateY(0); }
.btn svg { width: 1.125rem; height: 1.125rem; }

.btn--pillar-1 { --btn-bg: var(--color-pillar-1); --btn-bg-hover: var(--color-pillar-1-hover); }
.btn--pillar-2 { --btn-bg: var(--color-action); --btn-bg-hover: var(--color-action-hover); }
.btn--pillar-3 { --btn-bg: var(--color-pillar-3); --btn-bg-hover: var(--color-pillar-3-hover); }
.btn--ghost { --btn-bg: rgba(255,255,255,0.12); --btn-bg-hover: rgba(255,255,255,0.2); border: 1px solid rgba(255,255,255,0.3); }

/* ═══════════════════════════════════════════════════════════════════
   ABOUT SECTION (home page)
   ═══════════════════════════════════════════════════════════════════ */
.section {
  padding-block: var(--space-20);
}
.section--alt { background: var(--color-surface); }
.section--dark { background: var(--primitive-slate-900); color: var(--color-text-inverse); }

.section-header {
  margin-bottom: var(--space-12);
}
.section-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-action);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-3);
}
.section-title {
  font-size: clamp(var(--text-2xl), 3vw, var(--text-4xl));
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.2;
  color: var(--color-text-primary);
}
.section-desc {
  margin-top: var(--space-4);
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 700px;
  line-height: 1.65;
}

.about-text p { font-size: var(--text-lg); color: var(--color-text-secondary); line-height: 1.75; max-width: 80ch; }
.about-text p + p { margin-top: var(--space-5); }

/* ═══════════════════════════════════════════════════════════════════
   PILLAR CARDS (home page)
   ═══════════════════════════════════════════════════════════════════ */
.pillars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: var(--space-6);
}

.pillar-card {
  --card-accent: var(--color-action);
  --card-accent-light: var(--color-action-light);
  --card-accent-border: var(--color-action-light);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
  transition: border-color var(--ease-base), box-shadow var(--ease-base), transform var(--ease-base);
  box-shadow: var(--shadow-sm);
}
.pillar-card:hover {
  border-color: var(--card-accent);
  box-shadow: var(--shadow-xl);
  transform: translateY(-3px);
}
.pillar-card--1 { --card-accent: var(--color-pillar-1); --card-accent-light: var(--color-pillar-1-light); --card-accent-border: var(--color-pillar-1-border); }
.pillar-card--2 { --card-accent: var(--color-pillar-2); --card-accent-light: var(--color-pillar-2-light); --card-accent-border: var(--color-pillar-2-border); }
.pillar-card--3 { --card-accent: var(--color-pillar-3); --card-accent-light: var(--color-pillar-3-light); --card-accent-border: var(--color-pillar-3-border); }

.pillar-card-icon {
  width: 3.25rem;
  height: 3.25rem;
  background: var(--card-accent-light);
  border: 1px solid var(--card-accent-border);
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--card-accent);
}
.pillar-card-icon svg { width: 1.625rem; height: 1.625rem; }

.pillar-card-title {
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--color-text-primary);
  line-height: 1.3;
}

.pillar-card-desc {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  line-height: 1.65;
  flex: 1;
}

.pillar-card-topics {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  border-top: 1px solid var(--color-border-light);
  padding-top: var(--space-5);
}

.pillar-card-topics a {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: var(--space-1) 0;
  transition: color var(--ease-fast);
}
.pillar-card-topics a::before {
  content: "";
  width: 0.375rem;
  height: 0.375rem;
  border-radius: var(--radius-full);
  background: var(--card-accent);
  flex-shrink: 0;
  opacity: 0.6;
  transition: opacity var(--ease-fast);
}
.pillar-card-topics a:hover { color: var(--card-accent); }
.pillar-card-topics a:hover::before { opacity: 1; }

.pillar-card-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--card-accent);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  padding: var(--space-2) var(--space-4);
  background: var(--card-accent-light);
  border-radius: var(--radius-lg);
  transition: background var(--ease-fast), gap var(--ease-fast);
  align-self: flex-start;
  border: 1px solid var(--card-accent-border);
}
.pillar-card-link:hover {
  background: var(--card-accent-border);
  color: var(--card-accent);
  gap: var(--space-3);
  text-decoration-color: transparent;
}

/* ═══════════════════════════════════════════════════════════════════
   ARTICLES GRID (home page listing)
   ═══════════════════════════════════════════════════════════════════ */
.articles-columns {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-4);
}

.article-card {
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-5) var(--space-6);
  gap: var(--space-3);
  transition: border-color var(--ease-base), box-shadow var(--ease-base), transform var(--ease-fast);
  text-decoration: none;
  color: inherit;
}
.article-card:hover {
  border-color: var(--color-border-medium);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  text-decoration-color: transparent;
}
.article-tag {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-pillar-2);
}
.article-tag--p1 { color: var(--color-pillar-1); }
.article-tag--p2 { color: var(--color-pillar-2); }
.article-tag--p3 { color: var(--color-pillar-3); }
.article-card-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text-primary);
  line-height: 1.4;
}
.article-card-arrow {
  margin-top: auto;
  font-size: var(--text-sm);
  color: var(--color-action);
  font-weight: 500;
}

/* ═══════════════════════════════════════════════════════════════════
   BREADCRUMBS
   ═══════════════════════════════════════════════════════════════════ */
.breadcrumbs {
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--color-border-light);
  margin-bottom: var(--space-8);
}
.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  list-style: none;
  align-items: center;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.breadcrumbs li + li::before {
  content: "/";
  margin-right: var(--space-1);
  opacity: 0.5;
}
.breadcrumbs a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--ease-fast);
}
.breadcrumbs a:hover { color: var(--color-action); }
.breadcrumbs [aria-current="page"] { color: var(--color-text-primary); font-weight: 600; }

/* ═══════════════════════════════════════════════════════════════════
   ARTICLE CONTENT
   ═══════════════════════════════════════════════════════════════════ */
.article-layout {
  padding-block: var(--space-10) var(--space-20);
}

.article-content {
  /* Wide layout — no narrow column */
  width: 100%;
}

/* Headings */
.article-content h1 {
  font-size: clamp(var(--text-2xl), 4vw, var(--text-5xl));
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: var(--space-8);
  background: linear-gradient(135deg, var(--primitive-blue-700) 0%, var(--primitive-violet-600) 60%, var(--primitive-cyan-500) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.article-content h2 {
  font-size: clamp(var(--text-xl), 2.5vw, var(--text-3xl));
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--color-text-primary);
  margin-top: var(--space-16);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-border-light);
  position: relative;
}
.article-content h2::before {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 3rem;
  height: 2px;
  background: linear-gradient(90deg, var(--primitive-blue-600), var(--primitive-violet-600));
}

.article-content h3 {
  font-size: clamp(var(--text-lg), 2vw, var(--text-2xl));
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--color-text-primary);
  margin-top: var(--space-10);
  margin-bottom: var(--space-4);
}

.article-content h4 {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
}

.article-content h5, .article-content h6 {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-top: var(--space-6);
  margin-bottom: var(--space-2);
}

/* Anchor links on headings */
.article-content .header-anchor {
  opacity: 0;
  text-decoration: none;
  color: var(--color-text-muted);
  margin-left: var(--space-2);
  font-size: 0.75em;
  font-weight: 400;
  transition: opacity var(--ease-fast);
}
.article-content *:hover > .header-anchor,
.article-content .header-anchor:focus { opacity: 1; }

/* Paragraphs */
.article-content p {
  margin-bottom: var(--space-5);
  color: var(--color-text-secondary);
  font-size: var(--text-lg);
  line-height: 1.75;
}

/* Strong & em */
.article-content strong { color: var(--color-text-primary); font-weight: 700; }
.article-content em { font-style: italic; }

/* Links */
.article-content a {
  color: var(--color-action);
  font-weight: 500;
  text-decoration: underline;
  text-decoration-color: var(--color-action-light);
  text-underline-offset: 3px;
  text-decoration-thickness: 2px;
  transition: color var(--ease-fast), text-decoration-color var(--ease-fast), background var(--ease-fast);
  border-radius: 2px;
  padding: 0 2px;
}
.article-content a:hover {
  color: var(--color-action-hover);
  background: var(--color-action-light);
  text-decoration-color: currentColor;
}

/* Lists */
.article-content ul, .article-content ol {
  margin-bottom: var(--space-5);
  padding-left: var(--space-6);
  color: var(--color-text-secondary);
  font-size: var(--text-lg);
  line-height: 1.75;
}
.article-content ul { list-style: none; }
.article-content ul li { position: relative; padding-left: var(--space-5); margin-bottom: var(--space-2); }
.article-content ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 0.375rem;
  height: 0.375rem;
  border-radius: var(--radius-full);
  background: var(--color-action);
  opacity: 0.7;
}
.article-content ol { list-style: decimal; }
.article-content ol li { padding-left: var(--space-2); margin-bottom: var(--space-2); }
.article-content li + li {}
.article-content li > p { margin-bottom: var(--space-2); }

/* Nested lists */
.article-content ul ul, .article-content ol ul, .article-content ul ol, .article-content ol ol {
  margin-top: var(--space-2);
  margin-bottom: var(--space-2);
}

/* Inline code */
.article-content :not(pre) > code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-inline-code-bg);
  color: var(--color-inline-code-text);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--primitive-blue-200);
  white-space: nowrap;
}

/* Blockquote */
.article-content blockquote {
  margin: var(--space-6) 0;
  padding: var(--space-5) var(--space-6);
  background: var(--color-action-light);
  border-left: 4px solid var(--color-action);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}
.article-content blockquote p { color: var(--color-text-primary); margin-bottom: 0; font-size: var(--text-base); }

/* Horizontal rule */
.article-content hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--space-12) 0;
}

/* ═══════════════════════════════════════════════════════════════════
   CODE BLOCKS (Prism theme — light)
   ═══════════════════════════════════════════════════════════════════ */
.code-block {
  position: relative;
  margin: var(--space-6) 0;
}

pre[class*="language-"],
pre:not([class]) {
  background: var(--color-code-bg);
  border: 1px solid var(--color-code-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.7;
  tab-size: 2;
  margin: 0;
}

code[class*="language-"],
pre[class*="language-"] code,
pre:not([class]) code {
  font-family: var(--font-mono);
  font-size: inherit;
  background: none;
  border: none;
  padding: 0;
  color: var(--primitive-slate-800);
  white-space: pre;
  word-break: normal;
  word-spacing: normal;
}

/* Prism token colors — light theme */
.token.comment, .token.prolog, .token.doctype, .token.cdata {
  color: var(--primitive-slate-400);
  font-style: italic;
}
.token.punctuation { color: var(--primitive-slate-500); }
.token.namespace { opacity: 0.8; }
.token.property, .token.tag, .token.boolean, .token.constant, .token.symbol, .token.deleted {
  color: var(--primitive-violet-600);
}
.token.number { color: var(--primitive-orange-600); }
.token.selector, .token.attr-name, .token.string, .token.char, .token.builtin, .token.inserted {
  color: var(--primitive-green-600);
}
.token.operator, .token.entity, .token.url {
  color: var(--primitive-slate-600);
}
.token.atrule, .token.attr-value, .token.keyword {
  color: var(--primitive-blue-700);
  font-weight: 600;
}
.token.function, .token.class-name {
  color: var(--primitive-cyan-600);
}
.token.regex, .token.important, .token.variable {
  color: var(--primitive-amber-500);
}
.token.important, .token.bold { font-weight: 700; }
.token.italic { font-style: italic; }

/* Code language label */
pre[class*="language-"] {
  position: relative;
}

/* Copy button */
.copy-btn {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: background var(--ease-fast), color var(--ease-fast), border-color var(--ease-fast);
  font-family: var(--font-sans);
  line-height: 1.5;
}
.copy-btn:hover { background: var(--color-surface-overlay); color: var(--color-text-primary); border-color: var(--color-border-medium); }
.copy-btn.copied { background: var(--primitive-emerald-50); color: var(--primitive-emerald-700); border-color: var(--primitive-emerald-100); }

/* ═══════════════════════════════════════════════════════════════════
   TABLES
   ═══════════════════════════════════════════════════════════════════ */
.table-wrapper {
  overflow-x: auto;
  margin: var(--space-6) 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xs);
}

.article-content table,
.table-wrapper table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  min-width: 480px;
}

.article-content th,
.table-wrapper th {
  background: var(--color-surface-raised);
  color: var(--color-text-primary);
  font-weight: 700;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: var(--space-3) var(--space-5);
  text-align: left;
  border-bottom: 2px solid var(--color-border);
  white-space: nowrap;
}

.article-content td,
.table-wrapper td {
  padding: var(--space-3) var(--space-5);
  border-bottom: 1px solid var(--color-border-light);
  color: var(--color-text-secondary);
  vertical-align: top;
  line-height: 1.6;
}

.article-content tbody tr:last-child td,
.table-wrapper tbody tr:last-child td { border-bottom: none; }
.article-content tbody tr:hover td,
.table-wrapper tbody tr:hover td { background: var(--color-surface-raised); }

/* Inline code in tables */
.article-content td code { font-size: 0.8em; }

/* ═══════════════════════════════════════════════════════════════════
   TASK LIST CHECKBOXES
   ═══════════════════════════════════════════════════════════════════ */
.article-content .contains-task-list {
  list-style: none;
  padding-left: 0;
}
.article-content .contains-task-list li {
  padding-left: 0;
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}
.article-content .contains-task-list li::before { display: none; }

.article-content .task-list-item-checkbox,
.article-content input[type="checkbox"] {
  width: 1.1rem;
  height: 1.1rem;
  margin-top: 0.25rem;
  flex-shrink: 0;
  accent-color: var(--color-action);
  cursor: pointer;
  border-radius: var(--radius-sm);
}

/* ═══════════════════════════════════════════════════════════════════
   FAQ ACCORDIONS
   ═══════════════════════════════════════════════════════════════════ */
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  margin-bottom: var(--space-3);
  overflow: hidden;
  background: var(--color-surface);
  transition: border-color var(--ease-fast), box-shadow var(--ease-fast);
}
.faq-item[open] {
  border-color: var(--color-action);
  box-shadow: 0 0 0 3px var(--color-action-light);
}

.faq-question {
  padding: var(--space-4) var(--space-5);
  font-weight: 600;
  font-size: var(--text-base);
  color: var(--color-text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  transition: background var(--ease-fast);
}
.faq-question::-webkit-details-marker { display: none; }
.faq-question::marker { display: none; }
.faq-question:hover { background: var(--color-surface-raised); }
.faq-question::after {
  content: "+";
  font-size: var(--text-xl);
  font-weight: 300;
  color: var(--color-text-muted);
  flex-shrink: 0;
  transition: transform var(--ease-base);
}
.faq-item[open] .faq-question::after {
  transform: rotate(45deg);
  color: var(--color-action);
}

.faq-item p, .faq-item ul, .faq-item ol {
  padding: var(--space-2) var(--space-5) var(--space-5);
  color: var(--color-text-secondary);
  font-size: var(--text-base);
  line-height: 1.7;
  margin: 0;
}
.faq-item p + p { padding-top: 0; }

/* ═══════════════════════════════════════════════════════════════════
   FOOTER
   ═══════════════════════════════════════════════════════════════════ */
.site-footer {
  background: var(--primitive-slate-900);
  color: rgba(255,255,255,0.7);
  padding: var(--space-16) 0 var(--space-8);
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}

@media (max-width: 768px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
}

.footer-brand .site-logo { color: var(--primitive-white); }
.footer-brand .site-logo:hover { opacity: 0.8; }
.footer-brand p {
  margin-top: var(--space-4);
  font-size: var(--text-sm);
  line-height: 1.65;
  color: rgba(255,255,255,0.5);
  max-width: 28ch;
}

.footer-col-title {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.9);
  margin-bottom: var(--space-4);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.footer-links a {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.55);
  text-decoration: none;
  transition: color var(--ease-fast);
}
.footer-links a:hover { color: rgba(255,255,255,0.9); }

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: var(--text-xs);
  color: rgba(255,255,255,0.35);
}

/* ═══════════════════════════════════════════════════════════════════
   RESPONSIVE UTILITIES
   ═══════════════════════════════════════════════════════════════════ */
@media (max-width: 768px) {
  :root { --content-padding: var(--space-4); }

  .hero { padding: var(--space-16) var(--space-4) var(--space-12); }
  .section { padding-block: var(--space-12); }

  .pillars-grid { grid-template-columns: 1fr; }
  .articles-columns { grid-template-columns: 1fr; }

  .article-content h1 { font-size: var(--text-3xl); }
  .article-content h2 { font-size: var(--text-2xl); }
  .article-content h3 { font-size: var(--text-xl); }
  .article-content p, .article-content ul, .article-content ol { font-size: var(--text-base); }

  pre[class*="language-"] { border-radius: var(--radius-lg); padding: var(--space-4); }
}

@media (min-width: 1440px) {
  :root { --max-width: 1400px; }
}

/* ═══════════════════════════════════════════════════════════════════
   UTILITY CLASSES
   ═══════════════════════════════════════════════════════════════════ */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0;
  margin: -1px; overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border-width: 0;
}
.visually-hidden { composes: sr-only; }

/* Math/text code blocks (no color) */
pre.language-math, pre.language-text {
  background: var(--color-code-bg);
  color: var(--color-code-text);
}