:root {
  --bg: #FFFFFF;
  --ink: #000000;
  --ink-2: #4A4A4A;
  --ink-3: #8A8A8A;
  --rule: #000000;
  --rule-soft: #D8D8D8;
  --inv: #FFFFFF;
  --inv-ink: #000000;
  --sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Helvetica, Arial, sans-serif;
}
:root[data-theme='dark'] {
  --bg: #000000;
  --ink: #FFFFFF;
  --ink-2: #B8B8B8;
  --ink-3: #7A7A7A;
  --rule: #FFFFFF;
  --rule-soft: #2A2A2A;
  --inv: #000000;
  --inv-ink: #FFFFFF;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    --bg: #000000;
    --ink: #FFFFFF;
    --ink-2: #B8B8B8;
    --ink-3: #7A7A7A;
    --rule: #FFFFFF;
    --rule-soft: #2A2A2A;
    --inv: #000000;
    --inv-ink: #FFFFFF;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html {
  scroll-behavior: smooth;
  /* iOS Safari momentum scrolling for the page itself and any nested
     scroll container that inherits this — belt-and-braces alongside the
     per-element rules below. */
  -webkit-overflow-scrolling: touch;
  -webkit-text-size-adjust: 100%;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}
body {
  background: var(--bg); color: var(--ink); font-family: var(--sans);
  font-size: 15.5px; line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  overscroll-behavior-y: none;
}
a { color: var(--ink); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 28px; }
@media (max-width: 400px) { .wrap { padding: 0 18px; } }

/* ---- header ---- */
.fd-header {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; gap: 20px;
  padding: 0 22px; height: 58px;
  background: var(--bg); border-bottom: 1px solid var(--rule);
}
.fd-header-landing { position: static; border-bottom: 1px solid var(--rule); }
.fd-brand { display: flex; align-items: center; gap: 10px; font-weight: 400; font-size: 15px; letter-spacing: -.01em; min-width: 0; flex-shrink: 1; }
.fd-brand-text { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0; }
.fd-mark { width: 24px; height: 24px; border-radius: 6px; flex: none; display: block; }
.fd-toplink { margin-left: auto; font-size: 13.5px; font-weight: 500; color: var(--ink-2); }
.fd-toplink:hover { color: var(--ink); }
.fd-theme-toggle {
  border: 1px solid var(--rule); background: var(--bg); color: var(--ink-2);
  padding: 8px; cursor: pointer; margin-left: 8px;
  display: flex; align-items: center; justify-content: center;
}
.fd-theme-toggle:hover { background: var(--ink); color: var(--inv); }
.fd-header-landing .fd-theme-toggle { margin-left: auto; }
/* Show the icon for the mode a click switches *to* — moon while light, sun while dark. */
.fd-theme-toggle .icon-sun { display: none; }
.fd-theme-toggle .icon-moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) .fd-theme-toggle .icon-sun { display: block; }
  :root:not([data-theme='light']) .fd-theme-toggle .icon-moon { display: none; }
}
:root[data-theme='dark'] .fd-theme-toggle .icon-sun { display: block; }
:root[data-theme='dark'] .fd-theme-toggle .icon-moon { display: none; }
.fd-mobile-toggle {
  display: none; border: 1px solid var(--rule); background: var(--bg); color: var(--ink);
  padding: 6px 10px; cursor: pointer;
}

/* ---- docs layout ---- */
.fd-layout { display: flex; max-width: 1400px; margin: 0 auto; }
.fd-sidebar {
  width: 250px; flex-shrink: 0; padding: 18px 14px;
  border-right: 1px solid var(--rule);
  height: calc(100vh - 58px); height: calc(100dvh - 58px);
  position: sticky; top: 58px; overflow-y: auto;
  -webkit-overflow-scrolling: touch; overscroll-behavior: contain;
}
.fd-switch { position: relative; margin-bottom: 18px; }
.fd-switch-btn {
  width: 100%; display: flex; justify-content: space-between; align-items: center;
  border: 1px solid var(--rule); background: var(--bg); color: var(--ink);
  padding: 8px 11px; font-size: 12.5px; font-weight: 600; cursor: pointer; font-family: var(--sans);
}
.fd-switch-menu {
  display: none; position: absolute; top: calc(100% + 4px); left: 0; right: 0; z-index: 10;
  background: var(--bg); border: 1px solid var(--rule);
}
.fd-switch.open .fd-switch-menu { display: block; }
.fd-switch-menu a { display: block; padding: 8px 11px; font-size: 12.5px; color: var(--ink-2); }
.fd-switch-menu a:hover, .fd-switch-menu a.on { background: var(--ink); color: var(--inv); text-decoration: none; }

.fd-nav ul { list-style: none; margin: 0; padding-left: 14px; }
.fd-nav > ul { padding-left: 0; }
.fd-nav-heading { font-size: 11px; font-weight: 700; color: var(--ink-3); margin: 16px 0 5px; padding: 0 8px; }
.fd-nav-heading:first-child { margin-top: 2px; }
.fd-nav a { display: block; padding: 5px 8px; color: var(--ink-2); font-size: 13.5px; }
.fd-nav a:hover { background: var(--rule-soft); text-decoration: none; }
.fd-nav a.active { background: var(--ink); color: var(--inv); font-weight: 600; }

.fd-main { flex: 1; min-width: 0; padding: 36px 44px 70px; max-width: 960px; }
.fd-breadcrumb { font-size: 12.5px; color: var(--ink-3); margin: 0 0 20px; }
.fd-breadcrumb a { color: var(--ink-3); }

.fd-content img { max-width: 100%; height: auto; display: block; }
.fd-content > p:first-child:has(> img:only-child) { margin: 0 0 28px; }
.fd-content > p:first-child:has(> img:only-child) img { border: 1px solid var(--rule); }
.fd-content h1 { font-size: 30px; font-weight: 800; letter-spacing: -.01em; margin: 0 0 20px; }
.fd-content .fd-post-date { margin: -12px 0 24px; font-size: 13px; color: var(--ink-3); }
.fd-content h2 { font-size: 21px; font-weight: 700; margin: 40px 0 12px; border-top: 1px solid var(--rule); padding-top: 24px; }
.fd-content h3 { font-size: 17px; font-weight: 700; margin: 28px 0 10px; }
.fd-content p { margin: 16px 0; }
.fd-content blockquote {
  margin: 24px 0; padding: 14px 18px; border-left: 3px solid var(--ink); color: var(--ink-2); font-size: 14.5px;
}
.fd-content .fd-claim {
  font-size: 1.2em; padding-left: 16px; border-left: 3px solid var(--ink);
  margin: 28px 0; font-weight: 600;
}
.fd-content .fd-slot {
  font-family: var(--sans); font-size: 0.88em; font-style: italic; color: var(--ink-2);
  border-bottom: 1px dashed var(--ink-3);
}
/* Figures are dense diagrams drawn on a 1200px canvas, so they get the
   full width of the main column (breaking out of its side padding) rather
   than the narrower text measure. On phones the column is far narrower than
   the figure can be read at, so the figure fits the screen and a tap opens it
   full size (see .fd-lightbox) instead of bleeding off the edge. */
.fd-content .fd-plate { margin: 36px -44px; }
.fd-content .fd-plate-frame { border: 1px solid var(--rule); overflow-x: auto; -webkit-overflow-scrolling: touch; background: var(--bg); }
.fd-content .fd-plate-frame img { display: block; width: 100%; }
.fd-content .fd-plate figcaption { font-size: 14px; color: var(--ink-2); margin: 10px 44px 0; line-height: 1.5; }
@media (max-width: 900px) {
  .fd-content .fd-plate { margin-inline: -20px; }
  .fd-content .fd-plate figcaption { margin-inline: 20px; }
}
@media (max-width: 860px) {
  .fd-content .fd-plate-frame { border-inline: 0; overflow: hidden; }
  .fd-content .fd-plate-frame img { cursor: zoom-in; }
  .fd-content .fd-plate figcaption::before { content: "Tap the figure to enlarge it."; display: block; font-size: 12px; font-weight: 600; margin-bottom: 4px; }
}
/* Full-size viewer for figures on phones: the figure at near-native size,
   panned by touch inside a full-screen overlay. */
.fd-lightbox { position: fixed; inset: 0; z-index: 100000; background: #0A0A0B; display: flex; flex-direction: column; }
.fd-lightbox-bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 16px; color: #F4F4F2; font-size: 13px; }
.fd-lightbox-close { appearance: none; border: 1px solid rgba(255,255,255,.4); background: transparent; color: #F4F4F2; font: inherit; font-weight: 600; padding: 8px 14px; border-radius: 6px; }
.fd-lightbox-scroll { flex: 1; overflow: auto; -webkit-overflow-scrolling: touch; overscroll-behavior: contain; touch-action: pan-x pan-y pinch-zoom; }
.fd-lightbox-scroll img { display: block; width: 1100px; max-width: none; background: #F7F6F3; margin: 0 auto; }
.fd-content pre { background: #0A0A0B; color: #F4F4F2; padding: 16px; overflow-x: auto; -webkit-overflow-scrolling: touch; font-size: 13.5px; border: 1px solid var(--rule-soft); }
.fd-content code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
.fd-content :not(pre) > code { background: var(--rule-soft); padding: 2px 5px; font-size: 0.88em; }
.fd-content hr { border: 0; border-top: 1px solid var(--rule); margin: 32px 0; }

.fd-pf-filters { display: flex; flex-wrap: wrap; gap: 8px; margin: 36px 0 20px; }
.fd-pf-filter { font-family: var(--sans); font-size: 12.5px; font-weight: 600; border: 1px solid var(--rule); background: var(--bg); color: var(--ink-2); padding: 6px 14px; cursor: pointer; }
.fd-pf-filter.on { background: var(--ink); color: var(--inv); }
.fd-pf-filter:hover:not(.on) { background: var(--rule-soft); }
.fd-pf-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px,1fr)); border: 1px solid var(--rule); }
.fd-pf-card { padding: 20px; border-right: 1px solid var(--rule); border-bottom: 1px solid var(--rule); color: var(--ink); transition: background .15s; }
.fd-pf-card:hover { background: var(--rule-soft); text-decoration: none; }
.fd-pf-card[hidden] { display: none; }
.fd-pf-status { font-size: 10.5px; font-weight: 700; color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; }
.fd-pf-card h4 { font-size: 15px; font-weight: 700; margin: 10px 0 6px; }
.fd-pf-card p { font-size: 13px; color: var(--ink-2); margin: 0 0 14px; line-height: 1.5; }
.fd-pf-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.fd-pf-tags span { font-size: 10.5px; font-weight: 600; border: 1px solid var(--rule-soft); padding: 2px 8px; color: var(--ink-3); }

.fd-book-grid { display: flex; flex-direction: column; gap: 1px; background: var(--rule); border: 1px solid var(--rule); margin: 36px 0; }
.fd-book-card { display: flex; gap: 28px; align-items: flex-start; padding: 28px; background: var(--bg); color: var(--ink); transition: background .15s; }
.fd-book-card:hover { background: var(--rule-soft); text-decoration: none; }
.fd-book-cover { flex: none; width: 160px; aspect-ratio: 2 / 3; overflow: hidden; border: 1px solid var(--rule); }
.fd-book-cover img { width: 100%; height: 100%; object-fit: cover; display: block; }
.fd-book-info { min-width: 0; padding-top: 4px; }
.fd-book-status { font-size: 10.5px; font-weight: 700; color: var(--ink-3); text-transform: uppercase; letter-spacing: .06em; }
.fd-book-info h4 { font-size: 20px; font-weight: 700; margin: 10px 0 8px; }
.fd-book-info p { font-size: 14px; color: var(--ink-2); margin: 0; line-height: 1.6; max-width: 52ch; }
@media (max-width: 560px) {
  .fd-book-card { flex-direction: column; gap: 16px; }
  .fd-book-cover { width: 120px; }
}

.fd-stack { margin: 28px 0 40px; }
.fd-stack-toggle { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 20px; }
.fd-stack-toggle button { font-family: var(--sans); font-size: 13px; font-weight: 600; padding: 8px 16px; border: 1px solid var(--rule); background: var(--bg); color: var(--ink-2); cursor: pointer; }
.fd-stack-toggle button.on { background: var(--ink); color: var(--inv); }
.fd-stack-toggle button:hover:not(.on) { background: var(--rule-soft); }
.fd-stack-grid { display: grid; grid-template-columns: 72px 1fr 72px; gap: 10px; align-items: stretch; }
.fd-stack-persona { display: flex; align-items: center; justify-content: center; flex: none; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-3); text-align: center; }
.fd-stack-cells { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; }
.fd-stack-cell {
  border: 1px solid var(--rule-soft); padding: 14px 10px; font-size: 12.5px; font-weight: 600; color: var(--ink-2);
  text-align: center; display: flex; align-items: center; justify-content: center; min-height: 52px;
  transition: opacity .15s, border-color .15s, background .15s, color .15s;
}
.fd-stack-cell.fd-stack-on { border-color: var(--ink); background: var(--rule-soft); color: var(--ink); }
.fd-stack-cell.fd-stack-dim { opacity: .35; }
.fd-stack-shared { display: flex; flex-direction: column; gap: 1px; background: var(--rule-soft); border: 1px solid var(--rule-soft); margin-top: 10px; }
.fd-stack-row { background: var(--bg); padding: 10px 14px; font-size: 12.5px; font-weight: 600; color: var(--ink-3); text-align: center; }
.fd-stack-caption { font-size: 13px; color: var(--ink-2); margin: 16px 0 0; }
@media (max-width: 720px) {
  .fd-stack-grid { grid-template-columns: 1fr; }
  .fd-stack-persona { padding: 4px 0; }
  .fd-stack-cells { grid-template-columns: repeat(2, 1fr); }
}

.fd-pagenav { display: flex; justify-content: space-between; gap: 16px; margin-top: 52px; padding-top: 22px; border-top: 1px solid var(--rule); }
.fd-pagenav a { flex: 1; padding: 13px 15px; border: 1px solid var(--rule); color: var(--ink); }
.fd-pagenav a:hover { background: var(--ink); color: var(--inv); text-decoration: none; }
.fd-pn-next { text-align: right; }
.fd-pn-label { display: block; font-size: 10.5px; color: var(--ink-3); font-weight: 600; margin-bottom: 4px; }
.fd-pagenav a:hover .fd-pn-label { color: var(--ink-3); }


.fd-outline { width: 190px; flex: none; padding: 30px 16px; display: none; }
.fd-outline-label { font-size: 11px; font-weight: 700; color: var(--ink-3); margin: 0 0 10px; }
.fd-outline-link { display: block; font-size: 12.5px; padding: 5px 8px; color: var(--ink-2); border-left: 2px solid transparent; }
.fd-outline-link[data-level="3"] { padding-left: 18px; }
.fd-outline-link:hover { color: var(--ink); text-decoration: none; }
.fd-outline-link.active { color: var(--ink); border-left-color: var(--ink); font-weight: 600; }

@media (min-width: 1180px) { .fd-outline { display: block; } }

@media (max-width: 900px) {
  .fd-toplink { display: none; }
  .fd-sidebar {
    position: fixed; left: 0; top: 58px; bottom: 0; width: 260px;
    background: var(--bg); transform: translateX(-100%); transition: transform 0.15s;
    z-index: 20;
  }
  .fd-sidebar.open { transform: translateX(0); box-shadow: 2px 0 12px rgba(0,0,0,0.25); }
  .fd-mobile-toggle { display: inline-block; padding: 8px 11px; }
  .fd-main { padding: 26px 20px 56px; }
}

/* =========================================================
   LANDING — the Signal concept
   ========================================================= */
.fd-landing-body { background: #08080A; color: #F4F4F2; }
:root[data-theme='light'] .fd-landing-body { background: #FFFFFF; color: #000000; }
.fd-header-landing { background: inherit; color: inherit; border-color: var(--rule); }
.fd-landing-body .fd-header-landing { border-color: #2A2A2E; }
:root[data-theme='light'] .fd-landing-body .fd-header-landing { border-color: #000000; }

.fd-hero { padding-block: 90px 44px; position: relative; overflow: hidden; }
@media (max-width: 640px) { .fd-hero { padding-block: 56px 32px; } }
.fd-glow {
  position: absolute; top: -25%; right: -12%; width: 62%; height: 85%;
  background: url('/wash.jpg') center/cover; opacity: .18; filter: saturate(1.3);
  -webkit-mask-image: radial-gradient(circle at 70% 30%, black 0%, transparent 70%);
  mask-image: radial-gradient(circle at 70% 30%, black 0%, transparent 70%);
  pointer-events: none;
}
:root[data-theme='light'] .fd-glow { opacity: .32; }
.fd-eyebrow { display: flex; align-items: center; gap: 9px; font-weight: 600; font-size: 13px; color: #9A9A9E; margin: 0 0 20px; position: relative; z-index: 2; }
:root[data-theme='light'] .fd-eyebrow { color: #4A4A4A; }
.fd-hero-title {
  font-weight: 800; letter-spacing: -.03em; font-size: clamp(28px, 4.6vw, 48px); line-height: 1.14;
  margin: 0 0 22px; max-width: 20ch; position: relative; z-index: 2; text-wrap: balance;
}
.fd-hero-lede { font-size: 17px; color: #9A9A9E; max-width: 62ch; line-height: 1.65; margin: 0 0 24px; position: relative; z-index: 2; }
:root[data-theme='light'] .fd-hero-lede { color: #4A4A4A; }
.fd-hero-lede strong { color: inherit; font-weight: 700; }
.fd-lede-link { color: inherit; text-decoration: underline; white-space: nowrap; }

.fd-hero-ctas { position: relative; z-index: 2; margin: 0 0 8px; }
.fd-cta {
  display: inline-flex; align-items: center; gap: 6px;
  border: 1px solid var(--rule); background: var(--bg); color: inherit;
  padding: 9px 16px; font-size: 13.5px; font-weight: 600;
  text-decoration: none;
}
.fd-cta:hover { background: var(--ink); color: var(--inv); text-decoration: none; }
.fd-content .fd-cta { margin: -4px 0 24px; }

/* The landing hero defaults to dark regardless of the viewer's OS/data-theme
   preference (same "always-dark-by-default" pattern as .fd-release above),
   so its CTA can't rely on the --bg/--ink tokens the doc pages use. */
.fd-landing-body .fd-cta { border-color: #2A2A2E; background: transparent; }
:root[data-theme='light'] .fd-landing-body .fd-cta { border-color: #000000; }
.fd-landing-body .fd-cta:hover { background: #1A1A1D; color: inherit; }
:root[data-theme='light'] .fd-landing-body .fd-cta:hover { background: #F4F4F2; color: inherit; }

.fd-pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: #1A1A1D; border: 1px solid #1A1A1D; margin: 0 0 40px; }
:root[data-theme='light'] .fd-pillars { background: #E0E0E0; border-color: #E0E0E0; }
.fd-pillar { background: #08080A; padding: 22px 20px; }
:root[data-theme='light'] .fd-pillar { background: #FFFFFF; }
.fd-pillar h4 { font-size: 12.5px; font-weight: 700; margin: 0 0 8px; text-transform: uppercase; letter-spacing: .04em; color: #9A9A9E; }
:root[data-theme='light'] .fd-pillar h4 { color: #4A4A4A; }
.fd-pillar p { font-size: 13.5px; color: #B8B8BC; line-height: 1.55; margin: 0; }
:root[data-theme='light'] .fd-pillar p { color: #4A4A4A; }
@media (max-width: 640px) { .fd-pillars { grid-template-columns: 1fr; } }

.fd-release { display: flex; gap: 18px; align-items: center; border: 1px solid #2A2A2E; padding: 18px 20px; margin: 0 0 20px; color: inherit; }
:root[data-theme='light'] .fd-release { border-color: #000000; }
.fd-release:hover { background: #1A1A1D; text-decoration: none; }
:root[data-theme='light'] .fd-release:hover { background: #F4F4F2; }
.fd-release-cover { flex: none; width: 46px; aspect-ratio: 2/3; object-fit: cover; border: 1px solid #2A2A2E; }
:root[data-theme='light'] .fd-release-cover { border-color: #000000; }
.fd-release-body { flex: 1; min-width: 0; }
.fd-release-badge { display: block; font-size: 10.5px; font-weight: 700; text-transform: uppercase; letter-spacing: .07em; color: #9A9A9E; margin-bottom: 4px; }
:root[data-theme='light'] .fd-release-badge { color: #8A8A8A; }
.fd-release-body h5 { margin: 0 0 4px; font-size: 15px; font-weight: 700; }
.fd-release-body p { margin: 0; font-size: 13px; color: #9A9A9E; }
:root[data-theme='light'] .fd-release-body p { color: #4A4A4A; }
.fd-release-link { flex: none; font-size: 12.5px; font-weight: 700; text-decoration: underline; }
@media (max-width: 480px) {
  .fd-release { flex-direction: column; align-items: flex-start; gap: 12px; }
  .fd-release-link { align-self: flex-start; }
}

.fd-spaces-row { display: flex; flex-wrap: wrap; gap: 0; border-top: 1px solid #1A1A1D; margin-top: 60px; }
:root[data-theme='light'] .fd-spaces-row { border-color: #E0E0E0; }
.fd-spaces-row a { flex: 1; min-width: 200px; padding: 26px 4px 40px 0; border-bottom: 1px solid #1A1A1D; color: inherit; }
:root[data-theme='light'] .fd-spaces-row a { border-color: #E0E0E0; }
.fd-spaces-row a:not(:last-child) { border-right: 1px solid #1A1A1D; padding-right: 22px; margin-right: 22px; }
:root[data-theme='light'] .fd-spaces-row a:not(:last-child) { border-color: #E0E0E0; }
.fd-spaces-row a:hover { text-decoration: none; }
.fd-spaces-row a:hover h4 { text-decoration: underline; }
.fd-spaces-row h4 { font-size: 15px; font-weight: 700; margin: 0 0 4px; }
.fd-spaces-row p { font-size: 12.5px; color: #9A9A9E; margin: 0; line-height: 1.5; }
:root[data-theme='light'] .fd-spaces-row p { color: #4A4A4A; }

@media (max-width: 640px) {
  .fd-spaces-row a { min-width: 100%; border-right: 0 !important; padding-right: 0 !important; margin-right: 0 !important; }
}

/* ---- primary navigation (header on every page) ---- */
.fd-topnav { display: flex; align-items: center; gap: 4px; margin-left: auto; min-width: 0; }
.fd-topnav a { padding: 6px 10px; font-size: 13.5px; font-weight: 500; color: var(--ink-2); white-space: nowrap; border-bottom: 2px solid transparent; }
.fd-topnav a:hover { color: var(--ink); text-decoration: none; border-bottom-color: var(--rule-soft); }
.fd-topnav a.on { color: var(--ink); font-weight: 600; border-bottom-color: var(--ink); }
.fd-topnav + .fd-theme-toggle { margin-left: 8px; }
.fd-landing-body .fd-brand { color: inherit; }
.fd-landing-body .fd-theme-toggle { background: transparent; border-color: #2A2A2E; color: #9A9A9E; }
.fd-landing-body .fd-theme-toggle:hover { background: #1A1A1D; color: #F4F4F2; }
:root[data-theme='light'] .fd-landing-body .fd-theme-toggle { border-color: #000000; color: #4A4A4A; }
:root[data-theme='light'] .fd-landing-body .fd-theme-toggle:hover { background: #F4F4F2; color: #000000; }
.fd-landing-body .fd-topnav a { color: #9A9A9E; }
.fd-landing-body .fd-topnav a:hover { color: #F4F4F2; border-bottom-color: #2A2A2E; }
:root[data-theme='light'] .fd-landing-body .fd-topnav a { color: #4A4A4A; }
:root[data-theme='light'] .fd-landing-body .fd-topnav a:hover { color: #000000; border-bottom-color: #D8D8D8; }
/* the same links as a list at the top of the mobile sidebar drawer */
.fd-sidenav-primary { display: none; }
@media (max-width: 1100px) {
  .fd-topnav a { padding: 6px 7px; font-size: 13px; }
}
@media (max-width: 900px) {
  .fd-header > .fd-topnav { display: none; }
  .fd-header-landing > .fd-topnav {
    display: flex; order: 3; flex: 0 0 100%; margin-left: 0; overflow-x: auto; -webkit-overflow-scrolling: touch;
    padding-bottom: 4px;
  }
  .fd-header-landing { flex-wrap: wrap; height: auto; padding-block: 12px 4px; row-gap: 6px; }
  .fd-sidenav-primary { display: flex; flex-direction: column; margin-bottom: 14px; padding-bottom: 12px; border-bottom: 1px solid var(--rule-soft); }
  .fd-sidenav-primary a { padding: 7px 8px; font-size: 13.5px; color: var(--ink-2); }
  .fd-sidenav-primary a.on { background: var(--ink); color: var(--inv); font-weight: 600; }
}

/* ---- landing: identity hierarchy, builder stack, CTA footer ---- */
.fd-hero-title { max-width: 24ch; }
.fd-hero-role { display: block; font-weight: 600; font-size: .62em; letter-spacing: -.015em; line-height: 1.25; margin-top: 10px; color: #9A9A9E; }
:root[data-theme='light'] .fd-hero-role { color: #4A4A4A; }

.fd-section-label { font-size: 12.5px; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; margin: 44px 0 14px; color: #9A9A9E; }
:root[data-theme='light'] .fd-section-label { color: #4A4A4A; }
.fd-build-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: #1A1A1D; border: 1px solid #1A1A1D; }
:root[data-theme='light'] .fd-build-grid { background: #E0E0E0; border-color: #E0E0E0; }
.fd-build-card { background: #08080A; padding: 22px 20px; }
:root[data-theme='light'] .fd-build-card { background: #FFFFFF; }
.fd-build-kind { margin: 0 0 6px; font-size: 10.5px; font-weight: 700; text-transform: uppercase; letter-spacing: .07em; color: #9A9A9E; }
:root[data-theme='light'] .fd-build-kind { color: #8A8A8A; }
.fd-build-card h4 { margin: 0 0 8px; font-size: 17px; font-weight: 700; }
.fd-build-card h4 code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 16px; }
.fd-build-body { margin: 0 0 14px; font-size: 13.5px; line-height: 1.55; color: #B8B8BC; }
:root[data-theme='light'] .fd-build-body { color: #4A4A4A; }
.fd-build-links { margin: 0; display: flex; flex-wrap: wrap; gap: 8px 18px; font-size: 13px; font-weight: 600; }
.fd-build-links a { color: inherit; text-decoration: underline; }
@media (max-width: 640px) { .fd-build-grid { grid-template-columns: 1fr; } }

.fd-talk { margin: 56px 0 24px; padding-top: 28px; border-top: 1px solid var(--rule); }
.fd-landing-body .fd-talk { border-top-color: #2A2A2E; margin-bottom: 48px; }
:root[data-theme='light'] .fd-landing-body .fd-talk { border-top-color: #000000; }
.fd-content .fd-talk-title, .fd-talk-title { font-size: 21px; font-weight: 700; margin: 0 0 18px; border: 0; padding: 0; }
.fd-talk-areas { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-bottom: 22px; }
.fd-talk-area h3 { font-size: 14.5px; font-weight: 700; margin: 0 0 6px; }
.fd-talk-area p { font-size: 13.5px; line-height: 1.55; margin: 0; color: var(--ink-2); }
.fd-landing-body .fd-talk-area p { color: #B8B8BC; }
:root[data-theme='light'] .fd-landing-body .fd-talk-area p { color: #4A4A4A; }
.fd-talk-ctas { display: flex; flex-wrap: wrap; gap: 10px; }
.fd-content .fd-talk-ctas .fd-cta { margin: 0; }
@media (max-width: 760px) { .fd-talk-areas { grid-template-columns: 1fr; gap: 14px; } }

.fd-book-grid-single .fd-book-card { padding: 32px; }

/* ---- 404 page ---- */
.fd-404-wrap { padding-block: 120px; text-align: left; }
.fd-404-title { font-size: clamp(28px, 5vw, 46px); font-weight: 800; letter-spacing: -.02em; margin: 0 0 16px; }
.fd-404-body { color: var(--ink-2); font-size: 16px; max-width: 52ch; margin: 0 0 28px; }
.fd-404-back { display: inline-block; border: 1px solid var(--rule); padding: 11px 20px; font-weight: 600; font-size: 14px; }