/* =========================================================
   Et al. — marketing site
   Restrained. Native-Mac feel. Light + dark.
   Brand-aligned with the extension (cobalt accent, SF Pro,
   four signature highlight colors).
   ========================================================= */

:root {
  /* Surfaces — three-tier elevation (mirrors the extension) */
  --app-bg:       #f2f2f7;     /* base */
  --card-bg:      #ffffff;     /* tier 1: cards, hero visual */
  --card-bg-2:    #fbfbfd;     /* alt tier-1 for banding */
  --overlay-bg:   rgba(255,255,255,0.92);

  /* Ink */
  --text-primary:    #1d1d1f;
  --text-secondary:  #4a4a52;
  --text-tertiary:   #6e6e76;

  /* Hairlines */
  --hairline:        #e5e5ea;
  --hairline-strong: #d1d1d6;

  /* Accent — cobalt (matches the extension; see CLAUDE.md) */
  --accent-copy: #1d4ed8;       /* text/icons/focus rings */
  --accent-fill: #1d4ed8;       /* white-on-cobalt buttons */
  --accent-deep: #15309a;
  --accent-soft: rgba(29, 78, 216, 0.08);

  /* Signature highlight palette — used as section accents */
  --hl-yellow: #ffeb3b;
  --hl-green:  #b9f6ca;
  --hl-blue:   #80d8ff;
  --hl-pink:   #e91e63;
  --hl-yellow-soft: rgba(255, 235, 59, 0.55);

  /* Typography */
  --font-ui:   -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro", system-ui, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", system-ui, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, monospace;

  /* Radius — Apple HIG aligned */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;

  /* Layout */
  --max:     1080px;
  --reading: 680px;
  --pad-x:   clamp(1.25rem, 4vw, 2rem);

  /* Motion */
  --t-hover: 0.15s ease;
  --t-fade:  0.22s ease-out;
  --t-morph: 0.28s cubic-bezier(0.32, 0.72, 0, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --app-bg:       #000000;
    --card-bg:      #1c1c1e;
    --card-bg-2:    #2c2c2e;
    --overlay-bg:   rgba(40, 40, 42, 0.85);

    --text-primary:    #f5f5f7;
    --text-secondary:  #c7c7cc;
    --text-tertiary:   #8e8e93;

    --hairline:        #2c2c2e;
    --hairline-strong: #38383a;

    --accent-copy: #6aa1ff;
    --accent-deep: #82b3ff;
    --accent-soft: rgba(106, 161, 255, 0.10);

    /* Pink contrast tweak for dark surfaces */
    --hl-pink: #e91e63;
  }
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--app-bg);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.5;
  font-feature-settings: "kern", "liga", "ss01";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* ---------- Skip link ---------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--text-primary);
  color: var(--card-bg);
  padding: 0.6rem 1rem;
  z-index: 100;
  border-radius: 0 0 var(--radius-sm) 0;
  font-size: 14px;
}
.skip-link:focus { left: 0; }

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

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: 0;
  color: var(--text-primary);
}
h1 { letter-spacing: 0; }
p { margin: 0 0 1em; }

a {
  color: var(--accent-copy);
  text-decoration: none;
  transition: color var(--t-hover);
}
a:hover { color: var(--accent-deep); }

strong { font-weight: 600; color: var(--text-primary); }

/* Highlighter — the signature brand touch (used inline in headings) */
.hl {
  background: linear-gradient(
    180deg,
    transparent 14%,
    var(--hl-yellow-soft) 14%,
    var(--hl-yellow-soft) 88%,
    transparent 88%
  );
  padding: 0 0.08em;
}

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}
.container--reading {
  max-width: calc(var(--reading) + 2 * var(--pad-x));
}

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--app-bg) 90%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--hairline);
}
.nav-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 1.5rem;
  padding-block: 0.85rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 16px;
  letter-spacing: 0;
}
.brand:hover { color: var(--text-primary); }
.nav-inner > .brand { justify-self: start; }
.brand-pic {
  display: inline-flex;
  flex-shrink: 0;
  line-height: 0;
}
.brand-mark {
  width: 22px; height: 22px;
  border-radius: 5px;
  flex-shrink: 0;
  display: block;
  object-fit: cover;
}

.nav-links {
  grid-column: 2;
  justify-self: center;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  font-size: 14px;
  font-weight: 500;
}
.nav-links a {
  color: var(--text-secondary);
  padding: 0.4rem 0;
}
.nav-links a:hover { color: var(--text-primary); }
.nav-links a[aria-current="page"] { color: var(--text-primary); }

.nav-cta {
  grid-column: 3;
  justify-self: end;
  font-size: 14px;
  font-weight: 500;
  padding: 0.5rem 0.95rem;
  border-radius: 999px;
  background: var(--accent-fill);
  color: #fff;
  border: 1px solid var(--accent-fill);
  transition: background var(--t-hover), border-color var(--t-hover);
}
.nav-cta:hover {
  background: var(--accent-deep);
  border-color: var(--accent-deep);
  color: #fff;
}

.nav-toggle {
  justify-self: end;
  display: none;
  background: transparent;
  border: 1px solid var(--hairline-strong);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.7rem;
  font-family: inherit;
  font-size: 14px;
  cursor: pointer;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: inherit;
  font-size: 15px;
  font-weight: 500;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background var(--t-hover), border-color var(--t-hover), color var(--t-hover);
  min-height: 44px;
  white-space: nowrap;
}
.btn-primary {
  background: var(--accent-fill);
  color: #fff;
  border-color: var(--accent-fill);
}
.btn-primary:hover {
  background: color-mix(in srgb, #000 14%, var(--accent-fill));
  border-color: color-mix(in srgb, #000 14%, var(--accent-fill));
  color: #fff;
}
@media (prefers-color-scheme: dark) {
  .btn-primary:hover {
    background: color-mix(in srgb, #fff 12%, var(--accent-fill));
    border-color: color-mix(in srgb, #fff 12%, var(--accent-fill));
  }
}
.btn-secondary {
  background: var(--card-bg);
  color: var(--text-primary);
  border-color: var(--hairline-strong);
}
.btn-secondary:hover {
  background: color-mix(in srgb, var(--accent-copy) 8%, var(--card-bg));
  border-color: var(--accent-copy);
  color: var(--accent-copy);
}
.btn .arrow { display: inline-block; transition: transform 0.18s ease; }
.btn:hover .arrow { transform: translateX(2px); }

/* ---------- Sections ---------- */
section { padding: clamp(3.5rem, 7vw, 5.5rem) 0; }
.section-rule {
  border: 0;
  height: 1px;
  background: var(--hairline);
  margin: 0;
  max-width: var(--max);
  margin: 0 auto;
}

.section-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-copy);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 0.85rem;
}
.section-title {
  font-size: 2.5rem;
  line-height: 1.1;
  letter-spacing: 0;
  margin-bottom: 0.85rem;
  max-width: 22ch;
}
.section-intro {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 56ch;
  margin: 0 0 0.5em;
  line-height: 1.5;
}

/* ---------- Hero ---------- */
.hero {
  padding: clamp(3.5rem, 8vw, 6rem) 0 clamp(2.5rem, 5vw, 4rem);
}
.hero-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-copy);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 1.1rem;
}
.hero h1 {
  font-size: 4.25rem;
  line-height: 1.04;
  letter-spacing: 0;
  font-weight: 600;
  max-width: 16ch;
  margin-bottom: 1.1rem;
}
.hero-sub {
  font-size: 1.15rem;
  line-height: 1.5;
  color: var(--text-secondary);
  max-width: 52ch;
  margin-bottom: 1.85rem;
}
.hero-ctas {
  display: flex;
  gap: 0.7rem;
  align-items: center;
  flex-wrap: wrap;
}

/* ---------- Concept visuals ---------- */
.hero-visual {
  margin-top: clamp(2.5rem, 5vw, 4rem);
  max-width: 760px;
}
.product-concept,
.section-visual {
  background: var(--card-bg);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow:
    0 1px 2px rgba(0,0,0,0.04),
    0 20px 48px -24px rgba(0,0,0,0.18);
}
.concept-chrome {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.7rem 1rem;
  border-bottom: 1px solid var(--hairline);
  background: var(--card-bg-2);
}
.window-dots {
  display: inline-flex;
  gap: 0.38rem;
  flex-shrink: 0;
}
.window-dots span {
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--hairline-strong);
}
.concept-url {
  flex: 1;
  font-size: 12px;
  color: var(--text-tertiary);
  text-align: center;
  font-family: var(--font-ui);
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.concept-pill,
.concept-kicker,
.source,
.cite-format span {
  font-weight: 600;
  color: var(--accent-copy);
  letter-spacing: 0.02em;
  text-transform: uppercase;
  font-size: 11px;
}
.concept-pill {
  padding: 0.25rem 0.5rem;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  background: var(--card-bg);
  color: var(--text-secondary);
  letter-spacing: 0;
  text-transform: none;
  flex-shrink: 0;
}

.markup-stage {
  position: relative;
  min-height: 285px;
  padding: clamp(1.25rem, 3vw, 2rem);
  background:
    radial-gradient(circle at 18% 20%, color-mix(in srgb, var(--accent-copy) 18%, transparent), transparent 32%),
    linear-gradient(145deg, color-mix(in srgb, var(--card-bg-2) 72%, transparent), var(--card-bg));
}
.reader-sheet {
  width: min(100%, 560px);
  padding: clamp(1.1rem, 3vw, 1.6rem);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--card-bg) 92%, transparent);
}
.line {
  display: block;
  height: 12px;
  margin: 0.65rem 0;
  border-radius: 999px;
  background: color-mix(in srgb, var(--text-tertiary) 26%, transparent);
}
.line.wide { width: 92%; }
.line.medium { width: 70%; }
.line.short { width: 48%; }
.line.highlight {
  height: 18px;
  margin: 0.55rem 0;
  box-shadow: inset 0 -7px 0 color-mix(in srgb, #fff 18%, transparent);
}
.line.highlight.yellow { width: 58%; background: color-mix(in srgb, var(--hl-yellow) 72%, transparent); }
.line.highlight.green { width: 76%; background: color-mix(in srgb, var(--hl-green) 72%, transparent); }
.line.highlight.blue { width: 64%; background: color-mix(in srgb, var(--hl-blue) 72%, transparent); }
.selection-menu {
  position: absolute;
  right: clamp(1rem, 4vw, 2.5rem);
  top: clamp(1.1rem, 3vw, 2rem);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.45rem 0.55rem;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  background: var(--overlay-bg);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
}
.selection-menu span:not(.menu-note) {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 1px solid rgba(0,0,0,0.08);
}
.selection-menu .s-yellow { background: var(--hl-yellow); }
.selection-menu .s-green { background: var(--hl-green); }
.selection-menu .s-blue { background: var(--hl-blue); }
.selection-menu .s-pink { background: var(--hl-pink); }
.menu-note {
  margin-left: 0.25rem;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}
.note-bubble {
  position: absolute;
  right: clamp(1rem, 4vw, 2rem);
  bottom: clamp(1rem, 3vw, 1.6rem);
  width: min(285px, calc(100% - 2rem));
  padding: 0.85rem 1rem;
  border-left: 3px solid var(--accent-copy);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: color-mix(in srgb, var(--accent-copy) 11%, var(--card-bg));
  color: var(--text-secondary);
  font-size: 14px;
}
.note-kicker {
  display: block;
  margin-bottom: 0.2rem;
  color: var(--accent-copy);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.section-visual {
  margin-top: 2.25rem;
}
.library-concept {
  display: grid;
  grid-template-columns: minmax(220px, 0.75fr) minmax(0, 1.25fr);
  gap: 1px;
  background: var(--hairline);
}
.library-sidebar,
.library-results,
.citation-source,
.citation-output {
  background: var(--card-bg);
  padding: clamp(1rem, 3vw, 1.4rem);
}
.library-sidebar {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}
.search-field {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 38px;
  padding: 0 0.85rem;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  color: var(--text-tertiary);
  font-size: 13px;
}
.search-field span {
  width: 9px;
  height: 9px;
  border: 2px solid var(--text-tertiary);
  border-radius: 50%;
  box-shadow: 5px 5px 0 -3px var(--text-tertiary);
}
.scope-row {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  min-height: 34px;
  padding: 0 0.65rem;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
}
.scope-row.active {
  background: color-mix(in srgb, var(--accent-copy) 14%, var(--card-bg));
  color: var(--accent-copy);
}
.scope-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.scope-dot.blue { background: var(--accent-copy); }
.scope-dot.yellow { background: var(--hl-yellow); }
.scope-dot.green { background: var(--hl-green); }
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-top: auto;
}
.tag-cloud span {
  padding: 0.25rem 0.5rem;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  color: var(--text-secondary);
  font-size: 12px;
}
.library-results {
  display: grid;
  gap: 0.75rem;
}
.result-card,
.cite-format {
  border: 1px solid var(--hairline);
  border-radius: var(--radius-md);
  background: var(--card-bg-2);
}
.result-card {
  display: grid;
  gap: 0.45rem;
  padding: 0.95rem;
}
.result-card.primary {
  border-color: color-mix(in srgb, var(--accent-copy) 34%, var(--hairline));
  background: color-mix(in srgb, var(--accent-copy) 8%, var(--card-bg));
}
.result-card strong {
  font-size: 15px;
}
.result-line {
  display: block;
  width: 82%;
  height: 10px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--text-tertiary) 28%, transparent);
}
.result-line.yellow { width: 64%; background: color-mix(in srgb, var(--hl-yellow) 72%, transparent); }
.result-line.blue { width: 58%; background: color-mix(in srgb, var(--hl-blue) 72%, transparent); }
.result-line.green { width: 72%; background: color-mix(in srgb, var(--hl-green) 72%, transparent); }
.result-note {
  margin-top: 0.25rem;
  color: var(--text-secondary);
  font-size: 13px;
}
.citation-concept {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 0.9fr);
  gap: 1px;
  background: var(--hairline);
}
.metadata-grid {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 0.65rem 0.9rem;
  margin-top: 0.9rem;
  color: var(--text-tertiary);
  font-size: 13px;
}
.metadata-grid strong {
  color: var(--text-primary);
  font-size: 14px;
}
.source-lines {
  margin-top: 1.25rem;
}
.source-lines span {
  display: block;
  width: 100%;
  height: 12px;
  margin: 0.6rem 0;
  border-radius: 999px;
  background: color-mix(in srgb, var(--text-tertiary) 22%, transparent);
}
.source-lines span:nth-child(2) { width: 76%; }
.source-lines span:nth-child(3) { width: 58%; background: color-mix(in srgb, var(--hl-yellow) 60%, transparent); }
.citation-output {
  display: grid;
  gap: 0.75rem;
}
.cite-format {
  padding: 0.9rem;
}
.cite-format.active {
  border-color: color-mix(in srgb, var(--accent-copy) 34%, var(--hairline));
  background: color-mix(in srgb, var(--accent-copy) 8%, var(--card-bg));
}
.cite-format.ai {
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--accent-copy) 12%, var(--card-bg)), var(--card-bg-2));
}
.cite-format p {
  margin: 0.35rem 0 0;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.45;
}

/* ---------- Color palette row (the four signature colors) ---------- */
.palette {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 2rem 0 0;
}
.swatch {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.85rem;
  border-radius: 999px;
  border: 1px solid var(--hairline);
  background: var(--card-bg);
  font-size: 13px;
  font-weight: 500;
}
.swatch .dot {
  width: 14px; height: 14px;
  border-radius: 50%;
  border: 1px solid rgba(0,0,0,0.08);
}
.swatch.s-yellow .dot { background: var(--hl-yellow); }
.swatch.s-green  .dot { background: var(--hl-green); }
.swatch.s-blue   .dot { background: var(--hl-blue); }
.swatch.s-pink   .dot { background: var(--hl-pink); }

/* ---------- Feature cards grid ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 2.25rem;
}
.feature {
  padding: 1.5rem;
  background: var(--card-bg);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
}
.feature h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.45rem;
  letter-spacing: 0;
}
.feature p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}
.feature-bar {
  display: inline-block;
  width: 28px;
  height: 4px;
  border-radius: 2px;
  margin-bottom: 0.85rem;
  background: var(--accent-copy);
}
.feature-bar.s-yellow { background: var(--hl-yellow); }
.feature-bar.s-green  { background: var(--hl-green); }
.feature-bar.s-blue   { background: var(--hl-blue); }
.feature-bar.s-pink   { background: var(--hl-pink); }
.feature-bar.s-cobalt { background: var(--accent-copy); }

/* ---------- Steps ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 2.25rem;
  counter-reset: step;
}
.step {
  padding: 1.5rem;
  background: var(--card-bg);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
}
.step::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-copy);
  margin-bottom: 0.55rem;
  letter-spacing: 0.04em;
}
.step h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  letter-spacing: 0;
}
.step p {
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.5;
}

/* ---------- Prose (editorial body) ---------- */
.prose {
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: var(--reading);
}
.prose h2 {
  font-size: 1.7rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 2.5rem 0 0.7rem;
  line-height: 1.2;
  letter-spacing: 0;
}
.prose h2:first-child { margin-top: 0; }
.prose h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 1.8rem 0 0.45rem;
  letter-spacing: 0;
}
.prose ul, .prose ol { padding-left: 1.3rem; margin: 0.5rem 0 1.25rem; }
.prose li { margin-bottom: 0.35rem; }
.prose strong { color: var(--text-primary); font-weight: 600; }
.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--card-bg);
  padding: 0.1em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--hairline);
}
.prose kbd {
  font-family: inherit;
  font-size: 0.85em;
  font-weight: 500;
  background: var(--card-bg);
  border: 1px solid var(--hairline-strong);
  border-bottom-width: 2px;
  padding: 0.12em 0.5em;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  display: inline-block;
  min-width: 1.5em;
  text-align: center;
}
.prose a { font-weight: 500; }

/* ---------- FAQ ---------- */
.faq {
  margin-top: 1.75rem;
  max-width: var(--reading);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--card-bg);
}
.faq details {
  border-bottom: 1px solid var(--hairline);
}
.faq details:last-child { border-bottom: none; }
.faq summary {
  font-weight: 600;
  font-size: 16px;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.1rem 1.25rem;
  letter-spacing: 0;
  transition: color var(--t-hover), background var(--t-hover);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  margin-left: auto;
  color: var(--text-tertiary);
  font-weight: 400;
  font-size: 1.4rem;
  line-height: 1;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}
.faq details[open] summary::after { content: "−"; }
.faq summary:hover {
  color: var(--accent-copy);
  background: var(--accent-soft);
}
.faq .answer {
  padding: 0 1.25rem 1.25rem;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.6;
  max-width: 62ch;
}
.faq .answer p:last-child { margin-bottom: 0; }

/* ---------- Changelog ---------- */
.entry {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 2rem;
  padding: 2rem 0;
  border-bottom: 1px solid var(--hairline);
  max-width: 880px;
}
.entry:first-of-type { border-top: 1px solid var(--hairline); }
.entry .meta .ver {
  display: block;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text-primary);
  letter-spacing: 0;
}
.entry .meta .date {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-top: 0.25rem;
}
.entry h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  letter-spacing: 0;
}
.entry p { color: var(--text-secondary); font-size: 15px; margin-bottom: 0.7rem; }
.entry ul { padding-left: 1.3rem; margin: 0.3rem 0 0; }
.entry li { margin-bottom: 0.35rem; color: var(--text-secondary); font-size: 15px; }

/* ---------- Keyboard shortcut rows ---------- */
.kbd-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.7rem 1rem;
  background: var(--card-bg);
  border: 1px solid var(--hairline);
  border-bottom: none;
  color: var(--text-secondary);
  font-size: 15px;
}
.kbd-row:first-child { border-radius: var(--radius-md) var(--radius-md) 0 0; }
.kbd-row:last-child { border-radius: 0 0 var(--radius-md) var(--radius-md); border-bottom: 1px solid var(--hairline); }
.kbd-row .keys { display: inline-flex; gap: 0.25rem; min-width: 5rem; }
.kbd-row .label { flex: 1; color: var(--text-primary); }

/* ---------- Inline list (with hairlines) ---------- */
.list-clean {
  list-style: none;
  padding: 0;
  margin: 0;
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  background: var(--card-bg);
  overflow: hidden;
}
.list-clean li {
  padding: 0.95rem 1.1rem;
  border-bottom: 1px solid var(--hairline);
  color: var(--text-secondary);
  font-size: 15px;
}
.list-clean li:last-child { border-bottom: none; }
.list-clean li strong { color: var(--text-primary); font-weight: 600; }

/* ---------- CTA strip (bottom of pages) ---------- */
.cta-strip {
  text-align: center;
  background: var(--card-bg);
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
  padding: clamp(3.5rem, 7vw, 5rem) 0;
}
.cta-strip h2 {
  font-size: 2.5rem;
  line-height: 1.1;
  letter-spacing: 0;
  margin-bottom: 0.6rem;
  max-width: 18ch;
  margin-left: auto;
  margin-right: auto;
}
.cta-strip p {
  color: var(--text-secondary);
  font-size: 17px;
  max-width: 48ch;
  margin: 0 auto 1.6rem;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--app-bg);
  border-top: 1px solid var(--hairline);
  padding: 3rem 0 2rem;
  color: var(--text-secondary);
  font-size: 14px;
}
.footer .container {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 2.5rem;
}
.footer h5 {
  font-family: inherit;
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-tertiary);
  margin: 0 0 0.85rem;
}
.footer a {
  display: block;
  padding: 0.2rem 0;
  color: var(--text-secondary);
}
.footer a:hover { color: var(--text-primary); }
.footer-brand .brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  margin-bottom: 0.6rem;
}
.footer-brand p { color: var(--text-tertiary); max-width: 34ch; line-height: 1.5; font-size: 14px; }
.footer-meta {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--hairline);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  color: var(--text-tertiary);
  font-size: 13px;
}

/* ---------- Page header (interior pages) ---------- */
.page-header {
  padding: clamp(3rem, 7vw, 5rem) 0 clamp(1.5rem, 3vw, 2.5rem);
  border-bottom: 1px solid var(--hairline);
}
.page-header .page-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-copy);
  margin-bottom: 1rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.page-header h1 {
  font-size: 3.25rem;
  line-height: 1.05;
  letter-spacing: 0;
  font-weight: 600;
  max-width: 18ch;
  margin-bottom: 0.85rem;
}
.page-header .lede {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 56ch;
  margin: 0;
  line-height: 1.5;
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- Reduced transparency ---------- */
@media (prefers-reduced-transparency: reduce) {
  .nav,
  .selection-menu {
    background: var(--app-bg);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }
  .selection-menu { background: var(--card-bg); }
}

/* ---------- Responsive ---------- */
@media (max-width: 820px) {
  .nav-inner {
    grid-template-columns: minmax(0, 1fr) auto auto;
    gap: 0.75rem;
  }
  .brand {
    grid-column: 1;
    grid-row: 1;
  }
  .nav-cta {
    grid-column: 2;
    grid-row: 1;
  }
  .nav-toggle {
    grid-column: 3;
    grid-row: 1;
  }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    grid-column: 1 / -1;
    grid-row: 2;
    justify-self: stretch;
    width: 100%;
    position: static;
    flex-direction: column;
    align-items: flex-start;
    padding: 0.8rem 0 0.35rem;
    gap: 0.4rem;
    border-top: 1px solid var(--hairline);
    border-bottom: 0;
    z-index: 20;
  }
  .nav-toggle { display: block; }
  .nav { position: sticky; }
  .library-concept,
  .citation-concept {
    grid-template-columns: 1fr;
  }
  .hero h1 { font-size: 3rem; }
  .section-title,
  .cta-strip h2 { font-size: 2rem; }
  .page-header h1 { font-size: 2.6rem; }
  .entry { grid-template-columns: 1fr; gap: 0.4rem; }
  .footer .container { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 540px) {
  body { font-size: 15px; }
  .hero h1 { font-size: 2.35rem; }
  .hero-sub { font-size: 1.05rem; }
  .section-title,
  .cta-strip h2 { font-size: 1.75rem; }
  .prose h2 { font-size: 1.35rem; }
  .page-header h1 { font-size: 2.1rem; }
  .nav-inner { gap: 0.55rem; }
  .nav-cta {
    font-size: 13px;
    padding: 0.48rem 0.75rem;
  }
  .hero-ctas {
    align-items: flex-start;
    flex-direction: column;
  }
  .btn {
    justify-content: center;
    text-align: center;
    white-space: normal;
  }
  .btn .arrow { flex-shrink: 0; }
  .footer .container { grid-template-columns: 1fr; gap: 2rem; }
  .footer-meta { flex-direction: column; gap: 0.6rem; }
  .concept-chrome { padding: 0.55rem 0.85rem; }
  .markup-stage {
    display: grid;
    gap: 1rem;
    min-height: 0;
  }
  .selection-menu,
  .note-bubble {
    position: static;
    width: fit-content;
    max-width: 100%;
  }
  .note-bubble { width: auto; }
  .reader-sheet { width: 100%; }
  .library-sidebar,
  .library-results,
  .citation-source,
  .citation-output {
    padding: 1rem;
  }
}

@media (max-width: 360px) {
  .brand span { display: none; }
  .nav-cta {
    font-size: 12px;
    padding-inline: 0.65rem;
  }
}