/* PosIQ landing — static, no build step. Light/dark via prefers-color-scheme. */
:root{
  --bg:#f7f9f8; --surface:#ffffff; --ink:#14201c; --muted:#5d6e67;
  --line:#dbe4e0; --accent:#0c6b64; --accent-ink:#ffffff; --accent-soft:#e3efed;
  --gold:#a1720a; --good:#1d8a5a; --bad:#c2483f;
  --chip-beta:#0c6b64; --chip-beta-bg:#e3efed; --chip-road:#a1720a; --chip-road-bg:#f6eedb;
  --shadow:0 1px 3px rgba(20,32,28,.08);
}
@media (prefers-color-scheme: dark){
  :root{
    --bg:#0d1412; --surface:#141c19; --ink:#e4ece8; --muted:#94a59e;
    --line:#283430; --accent:#3fc4b7; --accent-ink:#06211e; --accent-soft:#123430;
    --gold:#d9a441; --good:#4cc98a; --bad:#ef8b84;
    --chip-beta:#3fc4b7; --chip-beta-bg:#123430; --chip-road:#d9a441; --chip-road-bg:#33270f;
    --shadow:0 1px 3px rgba(0,0,0,.4);
  }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);
  font:400 16.5px/1.6 Archivo,"Noto Sans SC","Helvetica Neue",Arial,sans-serif;
  -webkit-font-smoothing:antialiased}
:lang(zh){line-height:1.75}
a{color:var(--accent)}
img,svg{max-width:100%}
.wrap{max-width:1060px;margin:0 auto;padding:0 22px}
h1,h2,h3{line-height:1.18;text-wrap:balance;margin:0}
h1{font-size:clamp(1.9rem,4.5vw,2.9rem);font-weight:700;letter-spacing:-.01em}
h2{font-size:clamp(1.35rem,2.6vw,1.7rem);font-weight:650}
h3{font-size:1.02rem;font-weight:600}
p{margin:.7em 0}
.serif{font-family:"Source Serif 4","Noto Sans SC",Georgia,serif}
.mono{font-family:"IBM Plex Mono",Consolas,monospace}
.eyebrow{font-family:"IBM Plex Mono",monospace;font-size:.72rem;font-weight:600;
  letter-spacing:.16em;text-transform:uppercase;color:var(--accent)}
.muted{color:var(--muted)}

/* header */
header.site{position:sticky;top:0;z-index:20;background:var(--bg);
  border-bottom:1px solid var(--line)}
.nav{display:flex;align-items:center;gap:22px;padding:14px 0}
.logo{display:flex;align-items:center;gap:9px;text-decoration:none;color:var(--ink);
  font-weight:700;font-size:1.15rem;letter-spacing:-.01em}
.logo svg{flex:none}
.nav-links{display:flex;gap:18px;margin-left:auto;font-size:.9rem}
.nav-links a{color:var(--muted);text-decoration:none;font-weight:500}
.nav-links a:hover{color:var(--ink)}
.lang-btn{border:1px solid var(--line);background:var(--surface);color:var(--ink);
  border-radius:7px;padding:5px 11px;font:600 .78rem "IBM Plex Mono",monospace;cursor:pointer}
.lang-btn:hover{border-color:var(--accent)}
.btn{display:inline-block;background:var(--accent);color:var(--accent-ink);
  text-decoration:none;font-weight:600;font-size:.92rem;border-radius:9px;
  padding:11px 20px;border:1px solid transparent}
.btn:hover{filter:brightness(1.08)}
.btn.ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn.ghost:hover{border-color:var(--accent);color:var(--accent);filter:none}
.btn.small{padding:8px 14px;font-size:.84rem}

/* hero */
.hero{display:grid;grid-template-columns:1.05fr .95fr;gap:44px;align-items:center;
  padding:64px 0 56px}
.hero .sub{font-size:1.08rem;color:var(--muted);max-width:34em}
.hero-ctas{display:flex;gap:12px;flex-wrap:wrap;margin:22px 0 10px}
.hero-note{font-size:.8rem;color:var(--muted);max-width:40em}
.hero-fig{background:var(--surface);border:1px solid var(--line);border-radius:14px;
  padding:18px;box-shadow:var(--shadow)}
.hero-fig .cap{display:flex;justify-content:space-between;align-items:center;
  font-family:"IBM Plex Mono",monospace;font-size:.72rem;color:var(--muted);margin-bottom:8px}
.sig-chip{display:inline-block;font-family:"IBM Plex Mono",monospace;font-size:.7rem;
  font-weight:600;color:var(--good);background:color-mix(in srgb,var(--good) 14%,transparent);
  border-radius:20px;padding:2px 9px}

/* sections */
section.band{padding:52px 0;border-top:1px solid var(--line)}
.shead{max-width:44em;margin-bottom:26px}
.shead p{color:var(--muted)}
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;counter-reset:step}
.step{background:var(--surface);border:1px solid var(--line);border-radius:12px;
  padding:18px;box-shadow:var(--shadow)}
.step .n{font-family:"IBM Plex Mono",monospace;font-weight:600;color:var(--accent);
  font-size:.78rem;letter-spacing:.08em}
.step p{font-size:.9rem;color:var(--muted);margin:.4em 0 0}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:12px;
  padding:16px 18px;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:6px}
.card p{font-size:.87rem;color:var(--muted);margin:0}
.chip{align-self:flex-start;font-family:"IBM Plex Mono",monospace;font-size:.62rem;
  font-weight:600;letter-spacing:.06em;border-radius:20px;padding:2px 8px}
.chip.beta{color:var(--chip-beta);background:var(--chip-beta-bg)}
.chip.road{color:var(--chip-road);background:var(--chip-road-bg)}

/* signal language strip */
.sigrow{display:flex;gap:10px;flex-wrap:wrap;margin:14px 0}
.sigrow span{font-family:"IBM Plex Mono",monospace;font-size:.76rem;font-weight:600;
  border-radius:20px;padding:4px 12px;border:1px solid var(--line);background:var(--surface)}
.s-strong{color:var(--good)} .s-neutral{color:var(--muted)}
.s-weak{color:var(--gold)} .s-risk{color:var(--bad)}

/* trust */
.trust{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
.trust .card b{font-size:.95rem}
.affil{margin-top:20px;padding:14px 18px;border-left:3px solid var(--gold);
  background:var(--surface);border-radius:0 10px 10px 0;font-size:.9rem;max-width:60em}

/* beta CTA */
.cta-band{background:var(--surface);border:1px solid var(--line);border-radius:16px;
  padding:34px;display:grid;grid-template-columns:1.2fr .8fr;gap:28px;align-items:center;
  box-shadow:var(--shadow)}
.cta-band ul{margin:.5em 0 0;padding-left:1.2em;color:var(--muted);font-size:.9rem}
.cta-side{display:flex;flex-direction:column;gap:10px;align-items:flex-start}
.cta-side .mono{font-size:.8rem;color:var(--muted)}

/* footer */
footer.site{border-top:1px solid var(--line);margin-top:56px;padding:30px 0 44px;
  font-size:.85rem;color:var(--muted)}
.foot{display:flex;flex-wrap:wrap;gap:10px 26px;align-items:baseline}
.foot a{color:var(--muted)}
.foot a:hover{color:var(--ink)}
.foot .legal-note{width:100%;margin-top:12px;max-width:70em;font-size:.78rem}

/* legal pages */
.doc{max-width:760px;margin:0 auto;padding:40px 22px 80px}
.doc h1{font-size:1.7rem;margin-bottom:.2em}
.doc h2{font-size:1.12rem;margin:1.6em 0 .4em}
.doc p,.doc li{font-family:"Source Serif 4","Noto Sans SC",Georgia,serif;font-size:1rem}
.doc .draft{font-family:"IBM Plex Mono",monospace;font-size:.72rem;color:var(--gold);
  letter-spacing:.08em;text-transform:uppercase;font-weight:600}
.doc .back{font-size:.85rem}

/* i18n block toggling: html[data-lang="en"] shows .lang-en, hides .lang-zh */
html[data-lang="en"] .lang-zh{display:none}
html[data-lang="zh"] .lang-en{display:none}

@media (max-width:840px){
  .hero{grid-template-columns:1fr;padding:40px 0 36px}
  .steps{grid-template-columns:1fr}
  .cta-band{grid-template-columns:1fr;padding:24px}
  .nav-links{display:none}
}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}