:root{
  --bg: #FAFAF8;
  --bg-alt: #F1F0EB;
  --surface: #FFFFFF;
  --line: #E6E4DC;
  --ink: #1C1C1A;
  --ink-soft: #4A4A46;
  --muted: #7A7A73;
  --accent: #1F6F5C;
  --accent-ink: #143F35;
  --accent-tint: #E7F1EE;
  --radius: 14px;
  --maxw: 1080px;
  --shadow: 0 1px 2px rgba(28,28,26,0.04), 0 8px 24px rgba(28,28,26,0.05);
}
*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{
  font-family:'Manrope',sans-serif;
  font-weight:700;
  color:var(--ink);
  margin:0;
  letter-spacing:-0.01em;
}
a{color:inherit;text-decoration:none;}
img{max-width:100%;display:block;}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 28px;}
section{padding:96px 0;border-top:1px solid var(--line);}
section:first-of-type{border-top:none;}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-family:'Manrope',sans-serif;
  font-size:13px;font-weight:700;letter-spacing:0.08em;text-transform:uppercase;
  color:var(--accent);margin-bottom:14px;
}
.eyebrow::before{content:"";width:18px;height:2px;background:var(--accent);display:inline-block;border-radius:2px;}
.section-head{max-width:640px;margin-bottom:52px;}
.section-head h2{font-size:clamp(28px,3.4vw,36px);}
.section-head p{color:var(--muted);margin-top:12px;font-size:16.5px;}

/* ---------- Nav ---------- */
header.nav{
  position:sticky;top:0;z-index:50;
  background:rgba(250,250,248,0.86);
  backdrop-filter:saturate(180%) blur(10px);
  border-bottom:1px solid var(--line);
}
.nav-inner{
  max-width:var(--maxw);margin:0 auto;padding:18px 28px;
  display:flex;align-items:center;justify-content:space-between;
}
.brand{font-family:'Manrope',sans-serif;font-weight:800;font-size:17px;letter-spacing:-0.01em;}
.brand span{color:var(--accent);}
nav.links{display:flex;gap:36px;align-items:center;}
nav.links a{
  font-size:14.5px;font-weight:600;color:var(--ink-soft);
  position:relative;padding:4px 0;transition:color .2s ease;
}
nav.links a:hover{color:var(--ink);}
nav.links a::after{
  content:"";position:absolute;left:0;bottom:-2px;width:0;height:2px;
  background:var(--accent);transition:width .25s ease;border-radius:2px;
}
nav.links a:hover::after{width:100%;}
.nav-cta{
  padding:9px 18px;border-radius:999px;background:var(--ink);color:#fff !important;
  font-size:14px;font-weight:600;
}
.menu-btn{display:none;background:none;border:none;cursor:pointer;padding:6px;}
.menu-btn span{display:block;width:22px;height:2px;background:var(--ink);margin:5px 0;border-radius:2px;}

/* ---------- Hero ---------- */
.hero{padding:110px 0 90px;border-top:none;position:relative;overflow:hidden;}
.hero-grid{
  position:absolute;inset:0;
  background-image:
    radial-gradient(circle at 1.5px 1.5px, var(--line) 1.5px, transparent 0);
  background-size:28px 28px;
  -webkit-mask-image:linear-gradient(to bottom, black, transparent 75%);
  mask-image:linear-gradient(to bottom, black, transparent 75%);
  opacity:0.7;
}
.hero-inner{position:relative;max-width:760px;}
.status-pill{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--accent-tint);color:var(--accent-ink);
  padding:7px 14px 7px 10px;border-radius:999px;font-size:13px;font-weight:600;margin-bottom:26px;
}
.status-dot{width:7px;height:7px;border-radius:50%;background:var(--accent);box-shadow:0 0 0 3px var(--accent-tint);}
.hero h1{font-size:clamp(38px,6vw,60px);line-height:1.06;}
.hero .role{
  font-family:'Manrope',sans-serif;font-weight:600;color:var(--accent-ink);
  font-size:clamp(18px,2.4vw,22px);margin-top:16px;
}
.hero p.lede{color:var(--ink-soft);font-size:18px;max-width:560px;margin-top:18px;}
.hero-actions{display:flex;gap:14px;margin-top:36px;flex-wrap:wrap;}
.btn{
  display:inline-flex;align-items:center;gap:8px;padding:13px 24px;border-radius:10px;
  font-weight:600;font-size:14.5px;font-family:'Manrope',sans-serif;
  border:none;cursor:pointer;
  transition:transform .18s ease, box-shadow .18s ease, background .18s ease;
}
.btn-primary{background:var(--ink);color:#fff;}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 10px 24px rgba(28,28,26,0.18);}
.btn-ghost{background:var(--surface);color:var(--ink);border:1px solid var(--line);}
.btn-ghost:hover{transform:translateY(-2px);border-color:#cfcdc2;}
.hero-meta{
  display:flex;gap:28px;margin-top:56px;flex-wrap:wrap;
  padding-top:28px;border-top:1px solid var(--line);
}
.hero-meta .stat b{display:block;font-family:'Manrope',sans-serif;font-size:22px;font-weight:800;color:var(--ink);}
.hero-meta .stat span{font-size:13px;color:var(--muted);}
.hero-example{
  margin-top:36px;display:inline-flex;align-items:center;gap:14px;
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:16px 22px;box-shadow:var(--shadow);font-family:'Manrope',sans-serif;
  font-weight:700;font-size:17px;flex-wrap:wrap;
}
.hero-example .num{color:var(--ink-soft);}
.hero-example .arrow{color:var(--muted);}
.hero-example .word{color:var(--accent-ink);}

/* ---------- Demo ---------- */
.demo-tabs{display:flex;gap:10px;margin-bottom:28px;flex-wrap:wrap;}
.demo-tab{
  padding:10px 20px;border-radius:999px;border:1px solid var(--line);background:var(--surface);
  font-family:'Manrope',sans-serif;font-weight:600;font-size:14px;color:var(--ink-soft);cursor:pointer;
  transition:background .18s ease, color .18s ease, border-color .18s ease;
}
.demo-tab:hover{border-color:#cfcdc2;}
.demo-tab.active{background:var(--ink);color:#fff;border-color:var(--ink);}
.demo-panel{display:none;}
.demo-panel.active{display:block;}
.demo-card{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:32px;box-shadow:var(--shadow);
}
.demo-form{display:flex;gap:12px;flex-wrap:wrap;align-items:center;}
.demo-input{
  flex:1;min-width:220px;padding:13px 18px;border-radius:10px;border:1px solid var(--line);
  font-family:'Manrope',sans-serif;font-size:15px;font-weight:600;color:var(--ink);
  background:var(--bg-alt);outline:none;transition:border-color .18s ease;
}
.demo-input:focus{border-color:var(--accent);}
.demo-error{color:#B3432B;font-size:13.5px;font-weight:600;margin-top:12px;display:none;}
.demo-error.visible{display:block;}
.demo-result{margin-top:26px;padding-top:26px;border-top:1px solid var(--line);}
.demo-result-empty{color:var(--muted);font-size:14.5px;}
.best-match{
  display:inline-flex;align-items:center;gap:12px;background:var(--accent-tint);color:var(--accent-ink);
  padding:14px 20px;border-radius:12px;font-family:'Manrope',sans-serif;font-weight:800;font-size:22px;
}
.best-match-label{
  font-size:11px;text-transform:uppercase;letter-spacing:0.06em;color:var(--muted);
  font-weight:700;margin-bottom:10px;font-family:'Manrope',sans-serif;
}
.all-results{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px;}
.all-results .chip{
  background:var(--bg-alt);border:1px solid var(--line);color:var(--ink-soft);
  font-family:'Manrope',sans-serif;font-size:13.5px;font-weight:700;padding:8px 14px;border-radius:999px;
}
.result-number{
  font-family:'Manrope',sans-serif;font-weight:800;font-size:22px;color:var(--ink);
  background:var(--bg-alt);border:1px solid var(--line);padding:14px 20px;border-radius:12px;
  display:inline-block;
}
.demo-hint{color:var(--muted);font-size:13.5px;margin-top:14px;}
.example-chips{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:16px;}
.example-label{font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:0.05em;color:var(--muted);margin-right:2px;}
.example-chip{
  background:var(--bg-alt);border:1px solid var(--line);color:var(--ink-soft);
  font-family:'Manrope',sans-serif;font-size:13px;font-weight:700;padding:7px 13px;border-radius:999px;
  cursor:pointer;transition:background .18s ease, border-color .18s ease, color .18s ease;
}
.example-chip:hover{background:var(--accent-tint);border-color:var(--accent);color:var(--accent-ink);}

/* ---------- How it works ---------- */
.how-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;}
.how-card{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px;box-shadow:var(--shadow);
}
.how-card .step{
  width:32px;height:32px;border-radius:8px;background:var(--accent-tint);color:var(--accent-ink);
  display:flex;align-items:center;justify-content:center;font-weight:800;font-family:'Manrope',sans-serif;
  margin-bottom:16px;font-size:14px;
}
.how-card h3{font-size:16.5px;margin-bottom:8px;}
.how-card p{font-size:14.5px;color:var(--ink-soft);margin:0;}

/* ---------- Trie demo ---------- */
.trie-demo{
  margin-top:32px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:36px;box-shadow:var(--shadow);
}
.trie-demo-head{max-width:640px;margin-bottom:24px;}
.trie-demo-head h3{font-size:19px;margin-bottom:8px;}
.trie-demo-head p{font-size:14.5px;color:var(--ink-soft);margin:0;}
.trie-demo-body{display:flex;flex-direction:column;align-items:center;gap:18px;}
.trie-svg{width:100%;max-width:460px;height:auto;overflow:visible;}
.trie-edge{stroke:var(--line);stroke-width:2;transition:stroke .3s ease, stroke-width .3s ease;}
.trie-edge.active{stroke:var(--accent);stroke-width:3;}
.trie-node circle{
  fill:var(--bg-alt);stroke:var(--line);stroke-width:2;
  transition:fill .3s ease, stroke .3s ease, r .2s ease;
}
.trie-node text{
  font-family:'Manrope',sans-serif;font-weight:800;font-size:14px;fill:var(--ink-soft);
  text-anchor:middle;transition:fill .3s ease;pointer-events:none;
}
.trie-node.word-end circle{stroke-width:3;stroke:#cfcdc2;}
.trie-node.active circle{fill:var(--accent-tint);stroke:var(--accent);r:19;}
.trie-node.active text{fill:var(--accent-ink);}
.trie-node.found circle{fill:var(--accent);stroke:var(--accent-ink);}
.trie-node.found text{fill:#fff;}
.trie-node.notfound circle{fill:#F4E2DC;stroke:#B3432B;}
.trie-node.notfound text{fill:#B3432B;}
.trie-demo-status{
  display:flex;align-items:center;gap:10px;flex-wrap:wrap;justify-content:center;
  font-family:'Manrope',sans-serif;font-size:15px;
}
.trie-query-label{color:var(--muted);font-weight:600;}
.trie-query{font-weight:800;color:var(--ink);letter-spacing:0.02em;}
.trie-result{font-weight:700;font-size:13.5px;padding:5px 12px;border-radius:999px;}
.trie-result.found{background:var(--accent-tint);color:var(--accent-ink);}
.trie-result.notfound{background:#F4E2DC;color:#B3432B;}

/* ---------- Contact / CTA ---------- */
.contact-box{
  background:var(--ink);color:#fff;border-radius:20px;padding:64px 56px;
  display:grid;grid-template-columns:1.2fr 1fr;gap:40px;align-items:center;
}
.contact-box h2{color:#fff;font-size:clamp(26px,3.2vw,34px);}
.contact-box p{color:#C9C8C1;font-size:16px;margin-top:14px;max-width:420px;}
.contact-actions{display:flex;flex-direction:column;gap:12px;align-items:flex-start;}
.contact-box .btn-primary{background:#fff;color:var(--ink);}
.contact-box .btn-primary:hover{box-shadow:0 10px 24px rgba(0,0,0,0.35);}

footer{padding:36px 0;}
.footer-inner{
  display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;
  font-size:13.5px;color:var(--muted);
}

/* ---------- Reveal ---------- */
.reveal{opacity:0;transform:translateY(16px);transition:opacity .6s ease, transform .6s ease;}
.reveal.is-visible{opacity:1;transform:translateY(0);}

/* ---------- Responsive ---------- */
@media (max-width:860px){
  .how-grid{grid-template-columns:1fr;}
  .contact-box{grid-template-columns:1fr;padding:44px 32px;}
  .contact-actions{align-items:flex-start;}
}
@media (max-width:640px){
  section{padding:64px 0;}
  .hero{padding:76px 0 60px;}
  nav.links{
    position:fixed;top:64px;left:0;right:0;background:var(--bg);
    flex-direction:column;align-items:flex-start;gap:0;padding:8px 28px 20px;
    border-bottom:1px solid var(--line);
    transform:translateY(-8px);opacity:0;pointer-events:none;transition:opacity .2s ease, transform .2s ease;
  }
  nav.links.open{transform:translateY(0);opacity:1;pointer-events:auto;}
  nav.links a{padding:12px 0;width:100%;border-bottom:1px solid var(--line);}
  nav.links a:last-child{border-bottom:none;}
  .menu-btn{display:block;}
  .nav-cta{display:none;}
  .hero-meta{gap:22px;}
  .demo-form{flex-direction:column;align-items:stretch;}
}