/* ─────────────────────────────────────────────
   HELIUM DEVELOPER STANDARDS — STYLES
   Vercel-inspired premium dark theme
   Font: Geist + Geist Mono
───────────────────────────────────────────── */

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

:root {
  --bg:           #000000;
  --bg-1:         #0a0a0a;
  --bg-2:         #111111;
  --bg-3:         #1a1a1a;
  --bg-4:         #222222;
  --border:       #1f1f1f;
  --border-2:     #2a2a2a;
  --border-3:     #333333;
  --text-1:       #ededed;
  --text-2:       #a1a1a1;
  --text-3:       #666666;
  --text-4:       #444444;
  --accent:       #ffffff;
  --blue:         #3b82f6;
  --blue-dim:     rgba(59,130,246,0.12);
  --green:        #22c55e;
  --green-dim:    rgba(34,197,94,0.12);
  --red:          #ef4444;
  --red-dim:      rgba(239,68,68,0.12);
  --yellow:       #eab308;
  --yellow-dim:   rgba(234,179,8,0.12);
  --purple:       #a78bfa;
  --purple-dim:   rgba(167,139,250,0.12);
  --orange:       #f97316;
  --radius-sm:    6px;
  --radius:       10px;
  --radius-lg:    14px;
  --font:         'Geist', -apple-system, sans-serif;
  --font-mono:    'Geist Mono', 'Fira Code', monospace;
  --nav-h:        60px;
  --sidebar-w:    220px;
  --transition:   0.15s ease;
}

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 24px); }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text-1);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-3); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-4); }

/* ── SELECTION ── */
::selection { background: rgba(255,255,255,0.12); color: var(--text-1); }

/* ─────────────────────────────────────────────
   LAYOUT
───────────────────────────────────────────── */
.container { max-width: 960px; margin: 0 auto; padding: 0 24px; }
.container-wide { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ─────────────────────────────────────────────
   NAV
───────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(0,0,0,0.8);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition);
}
.nav.scrolled { border-bottom-color: var(--border-2); }

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}
.logo-mark {
  width: 28px; height: 28px;
  background: var(--text-1);
  color: var(--bg);
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: 700;
  letter-spacing: -0.5px;
}
.logo-text {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-1);
  letter-spacing: -0.2px;
}
.logo-sub {
  color: var(--text-3);
  font-weight: 400;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 1;
}
.nav-link {
  font-size: 13px;
  color: var(--text-2);
  text-decoration: none;
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
  white-space: nowrap;
}
.nav-link:hover { color: var(--text-1); background: var(--bg-3); }

.nav-mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  margin-left: auto;
}
.nav-mobile-toggle span {
  display: block;
  width: 20px; height: 1.5px;
  background: var(--text-2);
  border-radius: 2px;
  transition: all 0.2s ease;
}

.nav-mobile-menu {
  display: none;
  flex-direction: column;
  background: var(--bg-1);
  border-top: 1px solid var(--border);
  padding: 8px 0;
}
.nav-mobile-menu.open { display: flex; }
.nav-mobile-link {
  font-size: 14px;
  color: var(--text-2);
  text-decoration: none;
  padding: 10px 24px;
  transition: color var(--transition), background var(--transition);
}
.nav-mobile-link:hover { color: var(--text-1); background: var(--bg-3); }

/* ─────────────────────────────────────────────
   HERO
───────────────────────────────────────────── */
.hero {
  position: relative;
  padding: calc(var(--nav-h) + 80px) 0 80px;
  overflow: hidden;
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 30%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 30%, transparent 100%);
  opacity: 0.4;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-3);
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: 100px;
  padding: 5px 12px;
  margin-bottom: 28px;
  letter-spacing: 0.2px;
}
.badge-dot {
  width: 6px; height: 6px;
  background: var(--green);
  border-radius: 50%;
  box-shadow: 0 0 6px var(--green);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero-title {
  font-size: clamp(48px, 8vw, 80px);
  font-weight: 700;
  letter-spacing: -3px;
  line-height: 1.0;
  color: var(--text-1);
  margin-bottom: 24px;
}
.hero-title-accent {
  background: linear-gradient(135deg, #fff 0%, #666 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 17px;
  color: var(--text-2);
  max-width: 520px;
  line-height: 1.7;
  margin-bottom: 36px;
}
.hero-desc strong { color: var(--text-1); font-weight: 500; }

.hero-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--text-1);
  color: var(--bg);
  font-size: 14px;
  font-weight: 500;
  font-family: var(--font);
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: opacity var(--transition), transform var(--transition);
}
.btn-primary:hover { opacity: 0.88; transform: translateY(-1px); }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--text-2);
  font-size: 14px;
  font-weight: 400;
  font-family: var(--font);
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  border: 1px solid var(--border-2);
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition), transform var(--transition);
}
.btn-ghost:hover { color: var(--text-1); border-color: var(--border-3); transform: translateY(-1px); }

.hero-stats {
  display: flex;
  align-items: center;
  gap: 0;
  flex-wrap: wrap;
  gap: 0;
}
.stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 0 28px 0 0;
}
.stat:first-child { padding-left: 0; }
.stat-num {
  font-size: 24px;
  font-weight: 600;
  color: var(--text-1);
  letter-spacing: -1px;
  font-variant-numeric: tabular-nums;
}
.stat-label {
  font-size: 12px;
  color: var(--text-3);
  letter-spacing: 0.2px;
}
.stat-divider {
  width: 1px;
  height: 32px;
  background: var(--border-2);
  margin: 0 28px 0 0;
}

/* ─────────────────────────────────────────────
   TOC SECTION
───────────────────────────────────────────── */
.toc-section {
  padding: 0 0 80px;
  border-bottom: 1px solid var(--border);
}

.toc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.toc-card {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 20px;
  background: var(--bg-1);
  text-decoration: none;
  transition: background var(--transition);
  cursor: pointer;
}
.toc-card:hover { background: var(--bg-2); }

.toc-icon {
  font-size: 18px;
  color: var(--text-3);
  flex-shrink: 0;
  margin-top: 2px;
  width: 20px;
  text-align: center;
}

.toc-card-body { flex: 1; min-width: 0; }
.toc-num {
  font-size: 11px;
  font-family: var(--font-mono);
  color: var(--text-4);
  margin-bottom: 4px;
  letter-spacing: 0.5px;
}
.toc-title {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-1);
  margin-bottom: 4px;
  letter-spacing: -0.2px;
}
.toc-desc {
  font-size: 12px;
  color: var(--text-3);
  line-height: 1.5;
}

/* ─────────────────────────────────────────────
   MAIN CONTENT LAYOUT
───────────────────────────────────────────── */
.main-content { padding: 60px 0 80px; }

.content-layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  gap: 60px;
  align-items: start;
}

/* ─────────────────────────────────────────────
   SIDEBAR
───────────────────────────────────────────── */
.sidebar {
  position: sticky;
  top: calc(var(--nav-h) + 24px);
}
.sidebar-inner { padding: 0; }
.sidebar-heading {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-4);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 12px;
}
.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 1px;
}
.sidebar-link {
  font-size: 13px;
  color: var(--text-3);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
  border-left: 2px solid transparent;
}
.sidebar-link:hover { color: var(--text-2); background: var(--bg-2); }
.sidebar-link.active {
  color: var(--text-1);
  background: var(--bg-2);
  border-left-color: var(--text-1);
}

/* ─────────────────────────────────────────────
   DOC SECTIONS
───────────────────────────────────────────── */
.sections-content { min-width: 0; }

.doc-section {
  padding: 0 0 72px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 72px;
}
.doc-section:last-child { border-bottom: none; margin-bottom: 0; }

.section-header {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 32px;
}
.section-num {
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--text-4);
  flex-shrink: 0;
  letter-spacing: 0.5px;
}
.section-title {
  font-size: 26px;
  font-weight: 600;
  color: var(--text-1);
  letter-spacing: -0.8px;
  line-height: 1.2;
}

.subsection { margin-bottom: 32px; }
.subsection:last-child { margin-bottom: 0; }

.subsection-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-1);
  letter-spacing: -0.2px;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

.body-text {
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.7;
  margin-bottom: 16px;
}
.body-text strong { color: var(--text-1); font-weight: 500; }
.body-text em { color: var(--text-2); font-style: italic; }

/* ─────────────────────────────────────────────
   CODE BLOCKS
───────────────────────────────────────────── */
.code-block {
  background: var(--bg-1);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 16px;
  font-family: var(--font-mono);
}
.code-block-inline { margin-bottom: 0; border: none; background: transparent; }

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-2);
}
.code-lang {
  font-size: 11px;
  color: var(--text-4);
  font-family: var(--font-mono);
  letter-spacing: 0.5px;
  text-transform: lowercase;
}

.copy-btn {
  font-size: 11px;
  color: var(--text-3);
  background: none;
  border: 1px solid var(--border-2);
  border-radius: 4px;
  padding: 3px 8px;
  cursor: pointer;
  font-family: var(--font);
  transition: color var(--transition), border-color var(--transition), background var(--transition);
}
.copy-btn:hover { color: var(--text-1); border-color: var(--border-3); background: var(--bg-3); }
.copy-btn.copied { color: var(--green); border-color: var(--green); }

.code-block pre {
  padding: 16px;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-2);
}
.code-block code { font-family: var(--font-mono); }

/* Syntax tokens */
.token-comment { color: var(--text-4); font-style: italic; }
.token-green   { color: var(--green); }
.token-red     { color: var(--red); }
.token-blue    { color: #60a5fa; }
.token-yellow  { color: var(--yellow); }
.token-purple  { color: var(--purple); }
.token-orange  { color: var(--orange); }

/* ─────────────────────────────────────────────
   TABLES
───────────────────────────────────────────── */
.table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  margin-bottom: 16px;
}
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
.data-table thead tr {
  background: var(--bg-2);
  border-bottom: 1px solid var(--border-2);
}
.data-table th {
  padding: 10px 16px;
  text-align: left;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 0.6px;
  white-space: nowrap;
}
.data-table td {
  padding: 11px 16px;
  color: var(--text-2);
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}
.data-table tbody tr:last-child td { border-bottom: none; }
.data-table tbody tr:hover td { background: var(--bg-2); }
.data-table code {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-1);
  background: var(--bg-3);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--border-2);
}

/* ─────────────────────────────────────────────
   INLINE CODE
───────────────────────────────────────────── */
code {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-1);
  background: var(--bg-3);
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid var(--border-2);
}

/* ─────────────────────────────────────────────
   CALLOUTS
───────────────────────────────────────────── */
.callout {
  display: flex;
  gap: 14px;
  padding: 16px;
  border-radius: var(--radius);
  border: 1px solid;
  margin-bottom: 16px;
  font-size: 13px;
  line-height: 1.6;
}
.callout-icon {
  font-size: 14px;
  flex-shrink: 0;
  margin-top: 1px;
  width: 18px;
  text-align: center;
}
.callout-title {
  font-weight: 600;
  font-size: 13px;
  margin-bottom: 4px;
}
.callout p { color: inherit; opacity: 0.85; }
.callout code {
  background: rgba(255,255,255,0.08);
  border-color: rgba(255,255,255,0.1);
}

.callout-error {
  background: var(--red-dim);
  border-color: rgba(239,68,68,0.25);
  color: #fca5a5;
}
.callout-error .callout-title { color: var(--red); }

.callout-warning {
  background: var(--yellow-dim);
  border-color: rgba(234,179,8,0.25);
  color: #fde68a;
}
.callout-warning .callout-title { color: var(--yellow); }

.callout-info {
  background: var(--blue-dim);
  border-color: rgba(59,130,246,0.25);
  color: #93c5fd;
}
.callout-info .callout-title { color: var(--blue); }

/* ─────────────────────────────────────────────
   RULE LIST
───────────────────────────────────────────── */
.rule-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.rule-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 13.5px;
  color: var(--text-2);
  line-height: 1.6;
}
.rule-item strong { color: var(--text-1); font-weight: 500; }
.rule-item em { font-style: italic; }
.rule-item code {
  font-size: 12px;
  vertical-align: baseline;
}

.rule-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 7px;
}
.rule-dot-blue { background: var(--blue); }
.rule-dot-red  { background: var(--red); }
.rule-dot-green { background: var(--green); }

/* ─────────────────────────────────────────────
   BADGE TYPES
───────────────────────────────────────────── */
.badge-type {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  border: 1px solid;
  background: transparent;
}
.badge-feat     { color: #86efac; border-color: rgba(134,239,172,0.3); background: rgba(134,239,172,0.08); }
.badge-fix      { color: #fca5a5; border-color: rgba(252,165,165,0.3); background: rgba(252,165,165,0.08); }
.badge-docs     { color: #93c5fd; border-color: rgba(147,197,253,0.3); background: rgba(147,197,253,0.08); }
.badge-refactor { color: #c4b5fd; border-color: rgba(196,181,253,0.3); background: rgba(196,181,253,0.08); }
.badge-test     { color: #fde68a; border-color: rgba(253,230,138,0.3); background: rgba(253,230,138,0.08); }
.badge-chore    { color: #d1d5db; border-color: rgba(209,213,219,0.3); background: rgba(209,213,219,0.08); }
.badge-ci       { color: #f9a8d4; border-color: rgba(249,168,212,0.3); background: rgba(249,168,212,0.08); }
.badge-perf     { color: #fdba74; border-color: rgba(253,186,116,0.3); background: rgba(253,186,116,0.08); }

/* ─────────────────────────────────────────────
   PR SIZE METER
───────────────────────────────────────────── */
.size-meter { margin-bottom: 16px; }
.size-bar {
  display: flex;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border-2);
  height: auto;
}
.size-segment {
  flex: 1;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-right: 1px solid var(--border-2);
}
.size-segment:last-child { border-right: none; }
.size-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.size-range {
  font-size: 13px;
  font-family: var(--font-mono);
}
.size-green  { background: rgba(34,197,94,0.06);  }
.size-green .size-label  { color: var(--green); }
.size-green .size-range  { color: #86efac; }
.size-yellow { background: rgba(234,179,8,0.06);  }
.size-yellow .size-label { color: var(--yellow); }
.size-yellow .size-range { color: #fde68a; }
.size-red    { background: rgba(239,68,68,0.06);  }
.size-red .size-label    { color: var(--red); }
.size-red .size-range    { color: #fca5a5; }

/* ─────────────────────────────────────────────
   LIFECYCLE
───────────────────────────────────────────── */
.lifecycle {
  display: flex;
  align-items: flex-start;
  gap: 0;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}
.lifecycle-step {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: 14px;
  flex: 1;
  min-width: 120px;
}
.lifecycle-num {
  width: 22px; height: 22px;
  background: var(--bg-3);
  border: 1px solid var(--border-3);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 11px;
  font-family: var(--font-mono);
  color: var(--text-3);
  flex-shrink: 0;
}
.lifecycle-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-1);
  margin-bottom: 3px;
}
.lifecycle-desc {
  font-size: 11.5px;
  color: var(--text-3);
  line-height: 1.5;
}
.lifecycle-arrow {
  color: var(--text-4);
  font-size: 16px;
  align-self: center;
  flex-shrink: 0;
  display: none;
}

/* ─────────────────────────────────────────────
   BANNED GRID
───────────────────────────────────────────── */
.banned-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 8px;
  margin-bottom: 16px;
}
.banned-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  color: var(--text-2);
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  line-height: 1.4;
}
.banned-item::before {
  content: '✕';
  color: var(--red);
  font-size: 11px;
  flex-shrink: 0;
}
.banned-item code {
  font-size: 11px;
}

/* ─────────────────────────────────────────────
   VERSION CARDS
───────────────────────────────────────────── */
.version-cards {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.version-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: 20px 28px;
  min-width: 120px;
  transition: border-color var(--transition), background var(--transition);
}
.version-card:hover { border-color: var(--border-3); background: var(--bg-3); }
.version-icon { font-size: 22px; }
.version-name { font-size: 12px; color: var(--text-3); font-weight: 500; }
.version-num {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-1);
  font-family: var(--font-mono);
  letter-spacing: -0.5px;
}

/* ─────────────────────────────────────────────
   ENV LIST
───────────────────────────────────────────── */
.env-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.env-item {
  font-size: 13px;
  color: var(--text-2);
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  line-height: 1.5;
}

/* ─────────────────────────────────────────────
   TWO COLUMN
───────────────────────────────────────────── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

/* ─────────────────────────────────────────────
   INLINE LINK
───────────────────────────────────────────── */
.inline-link {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(59,130,246,0.3);
  transition: border-color var(--transition);
}
.inline-link:hover { border-bottom-color: var(--blue); }

/* ─────────────────────────────────────────────
   TEXT COLORS
───────────────────────────────────────────── */
.text-red { color: var(--red); font-size: 12px; }

/* ─────────────────────────────────────────────
   CHECKLIST
───────────────────────────────────────────── */
.checklist-group {
  margin-bottom: 28px;
}
.checklist-group-title {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 12px;
}
.checklist {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.check-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 13.5px;
  color: var(--text-2);
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition);
  line-height: 1.5;
  user-select: none;
}
.check-item:hover { background: var(--bg-2); }
.check-item input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 16px; height: 16px;
  border: 1.5px solid var(--border-3);
  border-radius: 4px;
  background: var(--bg-2);
  cursor: pointer;
  flex-shrink: 0;
  margin-top: 1px;
  transition: all var(--transition);
  position: relative;
}
.check-item input[type="checkbox"]:checked {
  background: var(--text-1);
  border-color: var(--text-1);
}
.check-item input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 4px; top: 1.5px;
  width: 5px; height: 9px;
  border: 2px solid var(--bg);
  border-top: none; border-left: none;
  transform: rotate(45deg);
}
.check-item:has(input:checked) {
  color: var(--text-4);
  text-decoration: line-through;
  text-decoration-color: var(--text-4);
}

.checklist-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}
.btn-check-all {
  font-size: 13px;
  font-family: var(--font);
  color: var(--bg);
  background: var(--text-1);
  border: none;
  border-radius: var(--radius-sm);
  padding: 7px 14px;
  cursor: pointer;
  font-weight: 500;
  transition: opacity var(--transition);
}
.btn-check-all:hover { opacity: 0.85; }
.btn-reset {
  font-size: 13px;
  font-family: var(--font);
  color: var(--text-2);
  background: none;
  border: 1px solid var(--border-2);
  border-radius: var(--radius-sm);
  padding: 7px 14px;
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition);
}
.btn-reset:hover { color: var(--text-1); border-color: var(--border-3); }
.check-progress {
  font-size: 12px;
  color: var(--text-3);
  font-family: var(--font-mono);
  margin-left: auto;
}

/* ─────────────────────────────────────────────
   QUICK REFERENCE
───────────────────────────────────────────── */
.quickref-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.qr-card {
  background: var(--bg-1);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: background var(--transition);
}
.qr-card:hover { background: var(--bg-2); }
.qr-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-4);
  text-transform: uppercase;
  letter-spacing: 0.6px;
}
.qr-value {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-1);
  background: none;
  border: none;
  padding: 0;
  line-height: 1.5;
  word-break: break-all;
}
.qr-card-compliance { grid-column: 1 / -1; }
.qr-card-compliance .qr-value { color: var(--yellow); }

/* ─────────────────────────────────────────────
   FOOTER
───────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border);
  padding: 28px 0;
  background: var(--bg-1);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-left {
  display: flex;
  align-items: center;
  gap: 10px;
}
.footer-logo {
  width: 24px; height: 24px;
  background: var(--text-1);
  color: var(--bg);
  border-radius: 5px;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 700;
}
.footer-text { font-size: 13px; color: var(--text-3); }
.footer-right {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--text-4);
}
.footer-divider { color: var(--border-3); }
.footer-compliance { color: var(--text-4); }

/* ─────────────────────────────────────────────
   BACK TO TOP
───────────────────────────────────────────── */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 38px; height: 38px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: 50%;
  color: var(--text-2);
  font-size: 16px;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease, background var(--transition);
  pointer-events: none;
  z-index: 50;
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.back-to-top:hover { background: var(--bg-4); color: var(--text-1); }

/* ─────────────────────────────────────────────
   SCROLL REVEAL ANIMATION
───────────────────────────────────────────── */
.doc-section {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s ease, transform 0.4s ease;
}
.doc-section.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ─────────────────────────────────────────────
   RESPONSIVE — TABLET
───────────────────────────────────────────── */
@media (max-width: 900px) {
  .content-layout {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .sidebar { display: none; }
  .nav-links { display: none; }
  .nav-mobile-toggle { display: flex; }
  .two-col { grid-template-columns: 1fr; }
  .lifecycle { flex-direction: column; }
  .lifecycle-step { flex: none; width: 100%; }
}

/* ─────────────────────────────────────────────
   RESPONSIVE — MOBILE
───────────────────────────────────────────── */
@media (max-width: 600px) {
  .container, .container-wide { padding: 0 16px; }
  .hero { padding: calc(var(--nav-h) + 48px) 0 48px; }
  .hero-title { letter-spacing: -2px; }
  .hero-stats { gap: 16px; flex-wrap: wrap; }
  .stat-divider { display: none; }
  .stat { padding: 0; }
  .toc-grid { grid-template-columns: 1fr; }
  .size-bar { flex-direction: column; }
  .size-segment { border-right: none; border-bottom: 1px solid var(--border-2); }
  .size-segment:last-child { border-bottom: none; }
  .version-cards { flex-direction: column; }
  .version-card { flex-direction: row; align-items: center; padding: 14px 18px; min-width: unset; }
  .banned-grid { grid-template-columns: 1fr; }
  .quickref-grid { grid-template-columns: 1fr; }
  .qr-card-compliance { grid-column: 1; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .back-to-top { bottom: 16px; right: 16px; }
  .checklist-actions { flex-wrap: wrap; }
  .check-progress { margin-left: 0; width: 100%; }
  .nav-inner { padding: 0 16px; }
  .section-title { font-size: 22px; }
}