/* ── Reset ── */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: 'Inter', system-ui, sans-serif;
      font-size: 15px;
      line-height: 1.65;
      color: var(--text);
      background: var(--ground);
    }
    a { color: inherit; text-decoration: none; }
    img { max-width: 100%; display: block; }
    code { font-family: 'JetBrains Mono', monospace; }

    /* ── Design tokens ── */
    :root {
      --sidebar-bg: #0F172A;
      --sidebar-text: #94A3B8;
      --accent: #0d6efd;
      --accent-dark: #0a58ca;
      --accent-subtle: #EFF6FF;
      --ground: #FFFFFF;
      --surface: #F8FAFC;
      --surface-2: #F1F5F9;
      --text: #0F172A;
      --muted: #64748B;
      --border: #E2E8F0;
      --blue: #2563EB;
      --blue-subtle: #EFF6FF;
      --green: #059669;
      --green-subtle: #ECFDF5;
      --red: #DC2626;
      --red-subtle: #FEF2F2;
      --purple: #7C3AED;
      --purple-subtle: #F5F3FF;
      --teal: #0D9488;
      --teal-subtle: #F0FDFA;
      --code-bg: #1E293B;
      --code-text: #E2E8F0;
      --sidebar-width: 292px;
      --topbar-h: 52px;
      --content-max: 860px;
      --radius: 8px;
    }

    /* ── Layout shell ── */
    .layout {
      display: flex;
      min-height: 100vh;
    }

    /* ── Sidebar ── */
    .sidebar {
      position: fixed;
      top: 0;
      left: 0;
      width: var(--sidebar-width);
      height: 100vh;
      background: var(--sidebar-bg);
      overflow-y: auto;
      overflow-x: hidden;
      display: flex;
      flex-direction: column;
      z-index: 100;
      scrollbar-width: thin;
      scrollbar-color: #334155 transparent;
    }
    .sidebar::-webkit-scrollbar { width: 4px; }
    .sidebar::-webkit-scrollbar-thumb { background: #334155; border-radius: 4px; }

    .sidebar-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 22px 20px 18px;
      border-bottom: 1px solid #1E293B;
    }
    .sidebar-logo-icon {
      width: 32px;
      height: 32px;
      background: var(--accent);
      border-radius: 7px;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }
    .sidebar-logo-icon i {
      color: #0F172A;
      font-size: 15px;
    }
    .sidebar-logo-text {
      display: flex;
      flex-direction: column;
      line-height: 1.15;
    }
    .sidebar-logo-name {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: 15px;
      color: #F1F5F9;
      letter-spacing: -0.01em;
    }
    .sidebar-logo-version {
      font-family: 'JetBrains Mono', monospace;
      font-size: 10px;
      color: var(--accent);
      letter-spacing: 0.04em;
    }

    /* ── Quick Start / Full Documentation switcher ── */
    .doc-switcher {
      display: flex; gap: 4px; margin: 14px 16px 2px; background: #1E293B; border-radius: 8px; padding: 3px;
    }
    .doc-switcher a {
      flex: 1; text-align: center; padding: 6px 8px; border-radius: 6px; font-size: 11.5px; font-weight: 600;
      color: #94A3B8; transition: background 0.15s, color 0.15s;
    }
    .doc-switcher a.active { background: var(--accent); color: #fff; }
    .doc-switcher a:hover:not(.active) { color: #E2E8F0; }

    .sidebar-nav {
      padding: 12px 0 24px;
      flex: 1;
    }

    .sidebar-section-label {
      font-size: 9.5px;
      font-weight: 600;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: #475569;
      padding: 18px 20px 6px;
    }

    .sidebar-link {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 7px 20px;
      color: var(--sidebar-text);
      font-size: 13px;
      font-weight: 500;
      transition: color 0.15s, background 0.15s, border-color 0.15s;
      border-left: 2px solid transparent;
      cursor: pointer;
    }
    .sidebar-link i {
      width: 15px;
      font-size: 12px;
      opacity: 0.7;
      flex-shrink: 0;
    }
    .sidebar-link:hover {
      color: #E2E8F0;
      background: rgba(255,255,255,0.04);
    }
    .sidebar-link.active {
      color: var(--accent);
      border-left-color: var(--accent);
      background: rgba(245,158,11,0.07);
    }
    .sidebar-link.active i { opacity: 1; }

    /* ── Main area ── */
    .main {
      margin-left: var(--sidebar-width);
      flex: 1;
      min-width: 0;
      display: flex;
      flex-direction: column;
    }

    /* ── Topbar ── */
    .topbar {
      position: sticky;
      top: 0;
      z-index: 90;
      height: var(--topbar-h);
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
    }
    .topbar-breadcrumb {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 13px;
      color: var(--muted);
    }
    .topbar-breadcrumb span { color: var(--border); }
    .topbar-breadcrumb a {
      color: var(--muted);
      transition: color 0.15s;
    }
    .topbar-breadcrumb a:hover { color: var(--text); }
    .topbar-breadcrumb .crumb-active {
      color: var(--text);
      font-weight: 600;
    }
    .topbar-links {
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .topbar-link {
      display: flex;
      align-items: center;
      gap: 6px;
      padding: 5px 12px;
      border-radius: 6px;
      font-size: 12.5px;
      font-weight: 500;
      color: var(--muted);
      transition: background 0.15s, color 0.15s;
    }
    .topbar-link:hover { background: var(--surface-2); color: var(--text); }
    .topbar-link i { font-size: 11px; }
    .topbar-link.primary {
      background: var(--accent);
      color: #0F172A;
      font-weight: 600;
    }
    .topbar-link.primary:hover { background: var(--accent-dark); color: #fff; }

    /* ── Content ── */
    .content {
      flex: 1;
      padding: 0 32px 80px;
    }
    .content-inner {
      max-width: var(--content-max);
      margin: 0 auto;
    }

    /* ── Doc sections ── */
    .doc-section {
      scroll-margin-top: calc(var(--topbar-h) + 16px);
      padding-top: 64px;
    }
    .doc-section + .doc-section {
      border-top: 1px solid var(--border);
    }

    /* ── Eyebrow ── */
    .eyebrow {
      font-size: 11px;
      font-weight: 600;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--accent-dark);
      margin-bottom: 10px;
    }

    /* ── Section headings ── */
    .section-title {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: 28px;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--text);
      margin-bottom: 12px;
    }
    .section-lead {
      font-size: 16px;
      color: var(--muted);
      line-height: 1.7;
      margin-bottom: 32px;
      max-width: 680px;
    }

    /* ── Subsection header with amber accent ── */
    .subsection-title {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 600;
      font-size: 17px;
      color: var(--text);
      margin: 32px 0 14px;
      padding-left: 14px;
      position: relative;
    }
    .subsection-title::before {
      content: '';
      position: absolute;
      left: 0;
      top: 3px;
      bottom: 3px;
      width: 3px;
      background: var(--accent);
      border-radius: 2px;
    }

    /* ── Hero ── */
    .hero {
      padding: 64px 0 56px;
      border-bottom: 1px solid var(--border);
    }
    .hero-badges {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      margin-bottom: 24px;
    }
    .badge {
      display: inline-flex;
      align-items: center;
      gap: 5px;
      padding: 3px 10px;
      border-radius: 20px;
      font-size: 11.5px;
      font-weight: 600;
    }
    .badge-amber { background: var(--accent-subtle); color: var(--accent-dark); border: 1px solid #BFDBFE; }
    .badge-blue  { background: var(--blue-subtle);   color: var(--blue);        border: 1px solid #BFDBFE; }
    .badge-green { background: var(--green-subtle);  color: var(--green);       border: 1px solid #A7F3D0; }

    .hero-h1 {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: clamp(34px, 5vw, 48px);
      line-height: 1.1;
      letter-spacing: -0.03em;
      color: var(--text);
      margin-bottom: 18px;
    }
    .hero-h1 .line-amber { color: var(--accent); display: block; }

    .hero-sub {
      font-size: 16px;
      color: var(--muted);
      line-height: 1.75;
      max-width: 620px;
      margin-bottom: 28px;
    }

    .hero-ctas {
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
      margin-bottom: 36px;
    }
    .cta-primary {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 10px 20px;
      background: var(--accent);
      color: #0F172A;
      font-weight: 700;
      font-size: 14px;
      border-radius: var(--radius);
      transition: background 0.15s, transform 0.1s;
    }
    .cta-primary:hover { background: var(--accent-dark); color: #fff; transform: translateY(-1px); }
    .cta-ghost {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 10px 18px;
      background: var(--ground);
      color: var(--text);
      font-weight: 600;
      font-size: 14px;
      border-radius: var(--radius);
      border: 1.5px solid var(--border);
      transition: background 0.15s, border-color 0.15s, transform 0.1s;
    }
    .cta-ghost:hover { background: var(--surface); border-color: #CBD5E1; transform: translateY(-1px); }

    /* ── Annotated hero code block — the aesthetic risk ──
       The hero thesis IS the Sigma rule itself, with amber annotation
       callouts floating off the right edge of the code block.
       Detection engineers read YAML natively; the annotations mirror how they
       already reason about rule metadata — ATT&CK assignments, TLP tags,
       UUID provenance. The callouts use absolute positioning inside a
       relatively-positioned wrapper that is given right-overflow room.
       On narrow viewports (< 1100px) the annotations collapse and the
       code block reads cleanly on its own. ── */
    .hero-rule-wrap {
      position: relative;
      margin-top: 8px;
    }
    .hero-code-block {
      background: var(--code-bg);
      border-radius: 10px;
      overflow: hidden;
      border: 1px solid #334155;
    }
    .code-block-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 10px 16px;
      background: #162032;
      border-bottom: 1px solid #334155;
    }
    .code-block-lang {
      font-family: 'JetBrains Mono', monospace;
      font-size: 11px;
      color: #64748B;
      letter-spacing: 0.06em;
      text-transform: uppercase;
    }
    .code-copy-btn {
      display: flex;
      align-items: center;
      gap: 6px;
      padding: 4px 10px;
      background: #1E293B;
      border: 1px solid #334155;
      border-radius: 5px;
      color: #94A3B8;
      font-size: 11.5px;
      font-family: 'Inter', sans-serif;
      cursor: pointer;
      transition: background 0.15s, color 0.15s;
    }
    .code-copy-btn:hover { background: #334155; color: #E2E8F0; }
    .code-block-body {
      padding: 18px 20px;
      overflow-x: auto;
    }
    .code-block-body pre {
      margin: 0;
      font-family: 'JetBrains Mono', monospace;
      font-size: 13px;
      line-height: 1.7;
      color: var(--code-text);
      background: transparent !important;
    }
    .code-block-body pre code { background: transparent !important; padding: 0 !important; }

    .hero-annotations {
      position: absolute;
      top: 44px;
      right: -224px;
      width: 210px;
      display: flex;
      flex-direction: column;
      gap: 0;
      pointer-events: none;
    }
    .hero-ann {
      display: flex;
      align-items: flex-start;
      gap: 8px;
      margin-bottom: 4px;
    }
    .hero-ann-line {
      width: 28px;
      height: 1px;
      background: var(--accent);
      opacity: 0.4;
      margin-top: 10px;
      flex-shrink: 0;
    }
    .hero-ann-label {
      background: var(--accent-subtle);
      border: 1px solid #BFDBFE;
      border-radius: 5px;
      padding: 3px 8px;
      font-size: 11px;
      font-weight: 600;
      color: var(--accent-dark);
      white-space: nowrap;
    }
    .ann-offset-0  { margin-top: 4px; }
    .ann-offset-1  { margin-top: 27px; }
    .ann-offset-2  { margin-top: 30px; }
    .ann-offset-3  { margin-top: 26px; }

    @media (max-width: 1100px) {
      .hero-annotations { display: none; }
    }

    /* ── Feature cards grid ── */
    .feature-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
      margin-top: 24px;
    }
    @media (max-width: 680px) {
      .feature-grid { grid-template-columns: 1fr; }
    }
    .feature-card {
      padding: 20px;
      border-radius: var(--radius);
      border: 1px solid var(--border);
      background: var(--surface);
      transition: box-shadow 0.2s, transform 0.15s;
    }
    .feature-card:hover { box-shadow: 0 4px 16px rgba(15,23,42,0.08); transform: translateY(-2px); }
    .feature-card-icon {
      width: 36px;
      height: 36px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 12px;
      font-size: 15px;
    }
    .icon-amber  { background: var(--accent-subtle);  color: var(--accent-dark); }
    .icon-blue   { background: var(--blue-subtle);    color: var(--blue); }
    .icon-green  { background: var(--green-subtle);   color: var(--green); }
    .icon-red    { background: var(--red-subtle);     color: var(--red); }
    .icon-purple { background: var(--purple-subtle);  color: var(--purple); }
    .icon-teal   { background: var(--teal-subtle);    color: var(--teal); }
    .feature-card-title {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 600;
      font-size: 14.5px;
      color: var(--text);
      margin-bottom: 6px;
    }
    .feature-card-desc {
      font-size: 13.5px;
      color: var(--muted);
      line-height: 1.6;
    }

    /* ── Install steps ── */
    .install-steps {
      display: flex;
      flex-direction: column;
      gap: 28px;
      margin-top: 24px;
    }
    .install-step {
      display: grid;
      grid-template-columns: 36px 1fr;
      gap: 16px;
      align-items: start;
    }
    .step-num {
      width: 36px;
      height: 36px;
      background: var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: 15px;
      color: #0F172A;
      flex-shrink: 0;
      margin-top: 2px;
    }
    .step-content-title {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 600;
      font-size: 16px;
      color: var(--text);
      margin-bottom: 10px;
    }

    /* ── Callouts ── */
    .callout {
      display: flex;
      gap: 12px;
      padding: 14px 16px;
      border-radius: var(--radius);
      border-left: 3px solid;
      margin: 20px 0;
      font-size: 14px;
    }
    .callout-amber { background: var(--accent-subtle); border-color: var(--accent);  color: #1E3A8A; }
    .callout-blue  { background: var(--blue-subtle);   border-color: var(--blue);    color: #1E3A8A; }
    .callout-green { background: var(--green-subtle);  border-color: var(--green);   color: #064E3B; }
    .callout-icon { font-size: 15px; margin-top: 1px; flex-shrink: 0; }
    .callout-body { flex: 1; line-height: 1.6; }
    .callout-body strong { display: block; font-weight: 600; margin-bottom: 3px; }

    /* ── Tables ── */
    .table-wrap {
      border: 1px solid var(--border);
      border-radius: var(--radius);
      overflow: hidden;
      margin: 20px 0;
      overflow-x: auto;
    }
    table {
      width: 100%;
      border-collapse: collapse;
      font-size: 13.5px;
    }
    th {
      background: var(--surface-2);
      font-weight: 600;
      font-size: 11.5px;
      text-transform: uppercase;
      letter-spacing: 0.06em;
      color: var(--muted);
      padding: 10px 16px;
      text-align: left;
    }
    td {
      padding: 11px 16px;
      color: var(--text);
      border-top: 1px solid var(--border);
      vertical-align: top;
    }
    tr:hover td { background: var(--surface); }
    .mono-badge {
      font-family: 'JetBrains Mono', monospace;
      font-size: 12px;
      font-weight: 500;
      background: var(--accent-subtle);
      color: var(--accent-dark);
      border: 1px solid #BFDBFE;
      padding: 2px 8px;
      border-radius: 5px;
      white-space: nowrap;
    }
    .mono-badge-blue {
      font-family: 'JetBrains Mono', monospace;
      font-size: 12px;
      background: var(--blue-subtle);
      color: var(--blue);
      border: 1px solid #BFDBFE;
      padding: 2px 8px;
      border-radius: 5px;
      white-space: nowrap;
    }

    /* ── Regular code block (non-hero) ── */
    .code-block {
      background: var(--code-bg);
      border-radius: 10px;
      overflow: hidden;
      border: 1px solid #334155;
      margin: 20px 0;
    }

    /* ── Bullet lists ── */
    .doc-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
      padding: 0;
      margin: 16px 0;
    }
    .doc-list li {
      display: flex;
      align-items: flex-start;
      gap: 10px;
      font-size: 14.5px;
      color: var(--text);
      line-height: 1.6;
    }
    .doc-list li::before {
      content: '';
      width: 6px;
      height: 6px;
      background: var(--accent);
      border-radius: 50%;
      flex-shrink: 0;
      margin-top: 8px;
    }

    /* ── Connector diagram (pure CSS flex) ── */
    .connector-diagram {
      display: flex;
      align-items: center;
      gap: 0;
      margin: 28px 0;
      overflow-x: auto;
      padding: 24px 0;
    }
    .conn-node {
      border-radius: 10px;
      padding: 18px 22px;
      min-width: 160px;
      text-align: center;
      flex-shrink: 0;
    }
    .conn-node-amber {
      border: 2px solid var(--accent);
      background: var(--accent-subtle);
    }
    .conn-node-blue {
      border: 2px solid var(--blue);
      background: var(--blue-subtle);
    }
    .conn-node-title {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: 14px;
      margin-bottom: 4px;
    }
    .conn-node-sub {
      font-size: 12px;
      color: var(--muted);
    }
    .conn-arrow {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      min-width: 100px;
      padding: 0 8px;
    }
    .conn-arrow-line {
      width: 100%;
      height: 2px;
      background: linear-gradient(to right, var(--accent), var(--blue));
      position: relative;
    }
    .conn-arrow-line::after {
      content: '';
      position: absolute;
      right: -1px;
      top: -5px;
      border: 6px solid transparent;
      border-left-color: var(--blue);
    }
    .conn-arrow-label {
      font-size: 11px;
      font-weight: 600;
      color: var(--muted);
      letter-spacing: 0.05em;
      text-transform: uppercase;
      white-space: nowrap;
    }

    /* ── Add-format steps ── */
    .contrib-steps {
      display: flex;
      flex-direction: column;
      gap: 20px;
      margin-top: 20px;
    }
    .contrib-step {
      display: flex;
      gap: 16px;
      align-items: flex-start;
    }
    .contrib-num {
      width: 28px;
      height: 28px;
      background: var(--accent);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: 13px;
      color: #0F172A;
      flex-shrink: 0;
      margin-top: 2px;
    }
    .contrib-body {
      flex: 1;
      font-size: 14.5px;
      color: var(--text);
      line-height: 1.65;
    }
    .contrib-body strong { font-weight: 600; display: block; margin-bottom: 4px; }
    .inline-code {
      font-family: 'JetBrains Mono', monospace;
      font-size: 12.5px;
      background: var(--surface-2);
      border: 1px solid var(--border);
      padding: 1px 6px;
      border-radius: 4px;
      color: var(--text);
    }

    /* ── Footer ── */
    .doc-footer {
      border-top: 1px solid var(--border);
      padding: 36px 32px;
      background: var(--surface);
      margin-left: var(--sidebar-width);
    }
    .doc-footer-inner {
      max-width: var(--content-max);
      margin: 0 auto;
      display: flex;
      align-items: flex-start;
      justify-content: space-between;
      gap: 24px;
      flex-wrap: wrap;
    }
    .footer-brand {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 10px;
    }
    .footer-brand-icon {
      width: 28px;
      height: 28px;
      background: var(--accent);
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .footer-brand-icon i { font-size: 13px; color: #0F172A; }
    .footer-brand-name {
      font-family: 'Space Grotesk', sans-serif;
      font-weight: 700;
      font-size: 14px;
    }
    .footer-meta {
      font-size: 12.5px;
      color: var(--muted);
      line-height: 1.7;
    }
    .footer-links {
      display: flex;
      gap: 20px;
    }
    .footer-link {
      font-size: 13px;
      color: var(--muted);
      display: flex;
      align-items: center;
      gap: 6px;
      transition: color 0.15s;
    }
    .footer-link:hover { color: var(--text); }

    /* ── Paragraph text ── */
    .doc-p {
      font-size: 14.5px;
      color: var(--text);
      line-height: 1.75;
      margin-bottom: 16px;
    }
    .doc-p:last-child { margin-bottom: 0; }
    .doc-p a { color: var(--blue); text-decoration: underline; text-underline-offset: 2px; }

    /* ── Responsive ── */
    @media (max-width: 840px) {
      .sidebar {
        position: fixed;
        transform: translateX(-100%);
        transition: transform 0.25s;
      }
      .sidebar.open { transform: translateX(0); }
      .main { margin-left: 0; }
      .doc-footer { margin-left: 0; }
      .topbar { padding: 0 16px; }
      .content { padding: 0 16px 80px; }
      .topbar-links .topbar-link span { display: none; }
      .menu-toggle { display: flex; }
    }
    @media (min-width: 841px) {
      .menu-toggle { display: none; }
    }
    .menu-toggle {
      background: none;
      border: none;
      cursor: pointer;
      color: var(--text);
      font-size: 18px;
      padding: 4px 8px;
      border-radius: 6px;
    }
    .menu-toggle:hover { background: var(--surface-2); }

    /* ── Reduced motion ── */
    @media (prefers-reduced-motion: reduce) {
      *, *::before, *::after { transition: none !important; animation: none !important; }
      html { scroll-behavior: auto; }
    }

    /* ── Focus styles ── */
    :focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
      border-radius: 3px;
    }

    /* ── White text on blue accent backgrounds ── */
    .sidebar-logo-icon i, .sidebar-logo-icon svg,
    .step-num, .contrib-num,
    .footer-brand-icon i, .footer-brand-icon svg { color: #ffffff; }
    .cta-primary { color: #ffffff; }
    .cta-primary:hover { color: #ffffff; }
    .topbar-link.primary { color: #ffffff; }
    .topbar-link.primary:hover { color: #ffffff; }

    /* ── Dark mode toggle ── */
    .theme-toggle {
      background: none;
      border: none;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 6px 8px;
      border-radius: 6px;
      color: var(--muted);
      transition: background 0.15s, color 0.15s;
    }
    .theme-toggle:hover { background: var(--surface-2); color: var(--text); }
    /* Sun = currently light, Moon = currently dark. No bare ".theme-toggle svg"
       rule here on purpose — it used to force display:block on BOTH icons at
       once (element+class beats a single class in specificity), which is why
       both were visible in light mode; each icon's own visible/hidden state is
       now the only rule controlling it. */
    .icon-sun { display: block; }
    .icon-moon { display: none; }
    [data-theme="dark"] .icon-sun { display: none; }
    [data-theme="dark"] .icon-moon { display: block; }

    /* ── Dark mode tokens ── */
    [data-theme="dark"] {
      --ground: #0F172A;
      --surface: #1E293B;
      --surface-2: #334155;
      --text: #F1F5F9;
      --muted: #94A3B8;
      --border: #1E293B;
      --blue: #60A5FA;
      --blue-subtle: rgba(37,99,235,0.18);
      --accent: #3B82F6;
      --accent-dark: #60A5FA;
      --accent-subtle: rgba(37,99,235,0.14);
      --green: #34D399;
      --green-subtle: rgba(5,150,105,0.15);
      --red: #F87171;
      --red-subtle: rgba(220,38,38,0.15);
      --purple: #A78BFA;
      --purple-subtle: rgba(124,58,237,0.15);
      --teal: #2DD4BF;
      --teal-subtle: rgba(13,148,136,0.15);
      --code-bg: #020617;
      --code-text: #CBD5E1;
    }
    [data-theme="dark"] .topbar {
      background: rgba(15,23,42,0.97);
      border-bottom-color: #1E293B;
    }
    [data-theme="dark"] .sidebar { background: #020617; }
    [data-theme="dark"] .doc-footer { background: #0a0f1a; border-top-color: #1E293B; }
    [data-theme="dark"] .hero { border-bottom-color: #1E293B; }
    [data-theme="dark"] .doc-section + .doc-section { border-top-color: #1E293B; }
    [data-theme="dark"] .hero-code-block { border-color: #1E293B; }
    [data-theme="dark"] .code-block-header { background: #0a0f1a; border-color: #1E293B; }
    [data-theme="dark"] .code-block { border-color: #1E293B; }
    [data-theme="dark"] .code-copy-btn { background: #1E293B; border-color: #334155; }
    [data-theme="dark"] .feature-card { background: #1E293B; border-color: #334155; }
    [data-theme="dark"] .callout-amber { background: rgba(37,99,235,0.12); color: #93C5FD; border-color: var(--accent); }
    [data-theme="dark"] .callout-blue  { background: rgba(37,99,235,0.12); color: #93C5FD; }
    [data-theme="dark"] .callout-green { background: rgba(5,150,105,0.12); color: #6EE7B7; }
    [data-theme="dark"] .table-wrap { border-color: #334155; }
    [data-theme="dark"] td { border-top-color: #334155; }
    [data-theme="dark"] th { background: #0a0f1a; }
    [data-theme="dark"] tr:hover td { background: #1E293B; }
    [data-theme="dark"] .conn-node-amber { background: rgba(37,99,235,0.12); }
    [data-theme="dark"] .conn-node-blue  { background: rgba(37,99,235,0.08); }
    [data-theme="dark"] .cta-ghost { border-color: #334155; background: #1E293B; color: var(--text); }
    [data-theme="dark"] .cta-ghost:hover { border-color: #475569; background: #334155; }
    [data-theme="dark"] .hero-ann-label { background: rgba(37,99,235,0.18); border-color: rgba(96,165,250,0.4); }

    /* Auto dark via OS preference (unless manually overridden) */
    @media (prefers-color-scheme: dark) {
      :root:not([data-theme="light"]) {
        --ground: #0F172A; --surface: #1E293B; --surface-2: #334155;
        --text: #F1F5F9; --muted: #94A3B8; --border: #1E293B;
        --blue: #60A5FA; --blue-subtle: rgba(37,99,235,0.18);
        --accent: #3B82F6; --accent-dark: #60A5FA; --accent-subtle: rgba(37,99,235,0.14);
        --green: #34D399; --green-subtle: rgba(5,150,105,0.15);
        --red: #F87171; --red-subtle: rgba(220,38,38,0.15);
        --purple: #A78BFA; --purple-subtle: rgba(124,58,237,0.15);
        --teal: #2DD4BF; --teal-subtle: rgba(13,148,136,0.15);
        --code-bg: #020617; --code-text: #CBD5E1;
      }
    }

    /* ── Back to top ── */
    .back-to-top {
      position: fixed; bottom: 28px; right: 28px; width: 44px; height: 44px; border-radius: 50%;
      background: var(--accent); color: #fff; border: none; cursor: pointer; font-size: 16px;
      display: flex; align-items: center; justify-content: center;
      box-shadow: 0 6px 20px rgba(13,110,253,0.35);
      opacity: 0; visibility: hidden; transform: translateY(8px);
      transition: opacity 0.2s, transform 0.2s, visibility 0.2s, background 0.15s;
      z-index: 150;
    }
    .back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }
    .back-to-top:hover { background: var(--accent-dark); }
    @media (max-width: 840px) { .back-to-top { right: 16px; bottom: 16px; } }