:root {
  --ink: #10141f;
  --muted: #5f6878;
  --line: #e4e7ee;
  --soft: #f7f8fb;
  --green: #178857;
  --green-soft: #e8f7ee;
  --amber: #d59a24;
  --amber-soft: #fff4d8;
  --blue: #2563eb;
  --blue-soft: #edf4ff;
  --red: #b42318;
  --red-soft: #fdebea;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  overflow-x: hidden;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: #fff;
  line-height: 1.55;
}
a { color: inherit; text-decoration: none; }
p { margin: 0; }
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(18px);
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 900; }
.brand-mark {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-size: 13px;
  font-weight: 950;
}
.nav { display: flex; align-items: center; gap: 16px; color: #374151; font-weight: 850; }
.nav a:hover { color: var(--green); }
.hero {
  width: min(1180px, calc(100% - 32px));
  min-height: calc(100vh - 76px);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 420px;
  gap: 44px;
  align-items: center;
  padding: 70px 0 90px;
}
.hero-copy { max-width: 740px; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  margin: 0 0 16px;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: #536071;
  font-size: 13px;
  font-weight: 850;
}
h1, h2, h3 { margin: 0; letter-spacing: 0; line-height: 1.03; }
h1 { font-size: clamp(50px, 8vw, 108px); }
h2 { font-size: clamp(34px, 5vw, 66px); }
h3 { font-size: 23px; }
.lead {
  margin-top: 24px;
  color: var(--muted);
  font-size: clamp(19px, 2vw, 25px);
  max-width: 720px;
}
.micro { margin-top: 18px; color: #6b7280; font-size: 15px; max-width: 720px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.primary, .secondary {
  min-height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  padding: 0 20px;
  font-weight: 900;
}
.primary { background: var(--ink); color: #fff; }
.secondary { border: 1px solid var(--line); background: #fff; color: var(--ink); }
.hero-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  background: linear-gradient(180deg, #fff, #f8fafc);
  box-shadow: 0 30px 90px rgba(16,20,31,.08);
}
.panel-row {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 16px;
  border-bottom: 1px solid var(--line);
  color: #536071;
  font-weight: 750;
}
.panel-row:last-child { border-bottom: 0; }
.panel-row b { color: var(--ink); }
.panel-row.strong { border-radius: 8px; background: var(--red-soft); color: var(--red); }
.panel-row.highlighted { border-radius: 8px; background: var(--green-soft); }
.panel-row.highlighted b { color: var(--green); }
section { padding: 86px 0; }
.section-head {
  width: min(980px, calc(100% - 32px));
  margin: 0 auto 34px;
  text-align: center;
}
.section-head p:not(.eyebrow) {
  max-width: 840px;
  margin: 18px auto 0;
  color: var(--muted);
  font-size: 19px;
}
.explain, .workflow, .tools, .faq, .keyword-map { background: var(--soft); }
.cards, .steps, .tool-grid, .guide-grid, .intent-grid, .deep-grid, .cluster-grid {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  display: grid;
  gap: 14px;
}
.cards.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.intent-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.deep-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.cluster-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.steps { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.tool-grid, .guide-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.cards article, .steps article, .tool-grid a, .guide-grid a, .intent-grid article, .deep-grid article, .cluster-grid article {
  min-height: 210px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 22px;
  box-shadow: 0 16px 50px rgba(16,20,31,.04);
}
.cards span, .tool-grid span, .guide-grid span {
  display: block;
  margin-top: 10px;
  color: var(--muted);
  font-weight: 700;
}
.cards article > span, .intent-grid span {
  margin: 0 0 10px;
  color: var(--green);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: .06em;
}
.intent-grid p {
  margin-top: 12px;
  color: var(--muted);
}
.intent-note {
  width: min(980px, calc(100% - 32px));
  margin: 18px auto 0;
  border: 1px solid #f3d79f;
  border-radius: 8px;
  background: var(--amber-soft);
  padding: 18px 20px;
  color: #6b4b10;
  font-weight: 750;
}
.steps span {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-weight: 950;
}
.steps h3 { margin-top: 14px; }
.cards p, .steps p, .deep-grid p, .cluster-grid p { margin-top: 12px; color: var(--muted); }
.deep-grid ul, .cluster-grid ul {
  margin: 14px 0 0;
  padding-left: 18px;
  color: var(--muted);
}
.deep-grid li, .cluster-grid li { margin: 7px 0; }
.deep-grid strong, .cluster-grid strong { color: var(--ink); }
.keyword-table {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  display: grid;
  gap: 10px;
}
.keyword-row {
  display: grid;
  grid-template-columns: 1.1fr 1.2fr 1fr;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  overflow: hidden;
  box-shadow: 0 12px 38px rgba(16,20,31,.035);
}
.keyword-row > div {
  padding: 16px 18px;
  border-right: 1px solid var(--line);
}
.keyword-row > div:last-child { border-right: 0; }
.keyword-row b { display: block; margin-bottom: 6px; color: var(--ink); }
.keyword-row span { color: var(--muted); font-size: 15px; }
.keyword-row.header {
  background: #10141f;
  color: #fff;
  font-size: 12px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: .08em;
}
.keyword-row.header > div { border-color: rgba(255,255,255,.12); }
.keyword-row.header span, .keyword-row.header b { color: #fff; }
.editorial-band {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 28px;
  box-shadow: 0 18px 60px rgba(16,20,31,.05);
}
.editorial-band p { color: var(--muted); font-size: 18px; }
.editorial-band p + p { margin-top: 14px; }
.editorial-band h3 { margin-bottom: 14px; }
.comparison { background: #fff; }
.table-wrap {
  width: min(1280px, calc(100% - 32px));
  margin: 0 auto;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 18px 60px rgba(16,20,31,.06);
}
table { width: 100%; min-width: 1080px; border-collapse: collapse; }
th {
  padding: 18px 16px;
  background: #f8fafc;
  color: #4b5563;
  text-align: left;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .08em;
}
td {
  padding: 20px 16px;
  border-top: 1px solid var(--line);
  vertical-align: top;
  color: #253041;
  font-weight: 650;
}
td small { display: block; margin-top: 5px; color: #6b7280; font-weight: 650; overflow-wrap: anywhere; }
tr.winner td { background: var(--green-soft); border-top-color: #bfe9cc; }
.yes, .partial {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  border-radius: 999px;
  padding: 3px 10px;
  font-weight: 900;
  white-space: nowrap;
}
.yes { background: var(--green-soft); color: var(--green); }
.partial { background: var(--amber-soft); color: var(--amber); }
.multiplechat {
  background: linear-gradient(135deg, #fff, #f8fafc 50%, #e8f7ee);
}
.split {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 420px;
  gap: 36px;
  align-items: center;
}
.split p:not(.eyebrow) { margin-top: 18px; color: var(--muted); font-size: 20px; }
.split .primary { margin-top: 24px; }
.mini-board {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 14px;
  box-shadow: 0 24px 70px rgba(16,20,31,.08);
}
.mini-board div {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  padding: 16px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-weight: 800;
}
.mini-board div:last-child { border-bottom: 0; }
.mini-board .final { border-radius: 8px; background: var(--green-soft); color: var(--green); justify-content: center; }
.safety { background: #10141f; color: #fff; }
.content { width: min(980px, calc(100% - 32px)); margin: 0 auto; }
.content p:not(.eyebrow) { margin-top: 20px; color: #cbd5e1; font-size: 20px; }
.references { background: #fff; }
.reference-list, .faq-list {
  width: min(980px, calc(100% - 32px));
  margin: 0 auto;
  display: grid;
  gap: 10px;
}
.reference-list a, details {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}
.reference-list a {
  display: block;
  padding: 16px 18px;
  color: #374151;
  font-weight: 700;
}
summary {
  cursor: pointer;
  padding: 18px 20px;
  color: var(--ink);
  font-size: 18px;
  font-weight: 900;
}
details p { padding: 0 20px 20px; color: var(--muted); font-size: 17px; }
.footer {
  padding: 34px 18px;
  border-top: 1px solid var(--line);
  color: #6b7280;
  text-align: center;
  font-size: 14px;
}
.footer p { max-width: 980px; margin: 0 auto; }
.footer p + p { margin-top: 8px; }
@media (max-width: 980px) {
  .topbar { position: static; flex-direction: column; justify-content: center; padding: 18px 0; }
  .nav { flex-wrap: wrap; justify-content: center; font-size: 14px; }
  .hero, .split { grid-template-columns: 1fr; min-height: auto; padding-top: 50px; }
  .hero-copy { text-align: center; margin: 0 auto; }
  .actions { justify-content: center; }
  .cards.three, .steps, .tool-grid, .guide-grid, .intent-grid, .deep-grid, .cluster-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .keyword-row { grid-template-columns: 1fr; }
  .keyword-row > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .keyword-row > div:last-child { border-bottom: 0; }
}
@media (max-width: 640px) {
  .brand { white-space: normal; }
  .nav { gap: 10px; }
  h1 { font-size: 46px; }
  h2 { font-size: 34px; }
  section { padding: 62px 0; }
  .cards.three, .steps, .tool-grid, .guide-grid, .intent-grid, .deep-grid, .cluster-grid { grid-template-columns: 1fr; }
  .primary, .secondary { width: 100%; }
  .panel-row { flex-direction: column; gap: 4px; }
}

/* language picker */
.language-picker{display:inline-flex;align-items:center;gap:6px;color:#536071;font-size:13px;font-weight:800}
.language-picker select{border:1px solid var(--line);border-radius:8px;padding:8px 10px;background:#fff;color:var(--ink);font:inherit;font-weight:800;cursor:pointer}

/* breadcrumb */
.crumbs{width:min(1180px,calc(100% - 32px));margin:16px auto 0;color:#6b7280;font-size:13px;font-weight:700}
.crumbs a{color:var(--green)}

/* article prose */
.prose{width:min(900px,calc(100% - 32px));margin:0 auto;display:grid;gap:18px}
.prose p{color:var(--muted);font-size:18px}
.prose h2{font-size:clamp(30px,4vw,46px)}
.prose h3{font-size:22px;margin-top:6px}
.prose ul{margin:0;padding-left:22px;color:var(--muted);font-size:18px}
.prose li{margin:7px 0}
.prose a.inline{color:var(--green);font-weight:800;text-decoration:underline}

/* Mobile navbar */
.mobile-nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  flex: 0 0 44px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  border: 1px solid var(--line, #e5e7eb);
  border-radius: 8px;
  background: var(--panel, var(--paper, #fff));
  color: var(--ink, #111827);
  cursor: pointer;
}
.mobile-nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 999px;
  background: currentColor;
  transition: transform .2s ease, opacity .2s ease;
}
.mobile-nav-open .mobile-nav-toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.mobile-nav-open .mobile-nav-toggle span:nth-child(2) { opacity: 0; }
.mobile-nav-open .mobile-nav-toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
@media (max-width: 780px) {
  .topbar {
    position: sticky;
    top: 0;
    min-height: 66px;
    flex-direction: row !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 12px;
    padding: 10px 0;
  }
  .topbar .brand {
    min-width: 0;
    overflow: hidden;
  }
  .topbar .brand span:last-child {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .topbar nav {
    display: none !important;
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    z-index: 50;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 12px;
    border: 1px solid var(--line, #e5e7eb);
    border-radius: 8px;
    background: var(--panel, var(--paper, #fff));
    box-shadow: 0 22px 60px rgba(15, 23, 42, .16);
  }
  .topbar.mobile-nav-open nav { display: flex !important; }
  .topbar nav a {
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    border-radius: 8px;
    padding: 10px 12px;
    white-space: normal;
  }
  .topbar nav a:hover { background: rgba(15, 23, 42, .06); }
  .topbar .mobile-nav-toggle,
  .nav-inner .mobile-nav-toggle { display: inline-flex; }
  .nav-inner { position: relative; }
  .nav-inner .links { display: none; }
  .nav.mobile-nav-open .links {
    display: flex;
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    z-index: 50;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 12px;
    border: 1px solid var(--line, #e5e7eb);
    border-radius: 8px;
    background: #fff;
    box-shadow: 0 22px 60px rgba(15, 23, 42, .16);
  }
  .nav.mobile-nav-open .links a {
    min-height: 44px;
    display: flex;
    align-items: center;
    border-radius: 8px;
    padding: 10px 12px;
  }
  .nav.mobile-nav-open .links a:hover { background: rgba(15, 23, 42, .06); }
}