:root{
  --ink:#16203a; --muted:#5d6b86; --faint:#8a95ac; --line:#e6e9f2; --bg:#f5f7fb; --card:#fff;
  --brand:#4f46e5; --brand2:#0ea5a3; --brand-ink:#3a32c9;
  --ok:#10916b; --warn:#c2820a; --crit:#d23a52;
  --radius:16px; --shadow:0 2px 14px rgba(20,30,60,.06);
}
*{box-sizing:border-box}
html,body{margin:0}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.55}
a{color:var(--brand);text-decoration:none}
.container{max-width:1080px;margin:0 auto;padding:0 22px}

/* nav */
.nav{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.86);backdrop-filter:saturate(1.4) blur(8px);border-bottom:1px solid var(--line)}
.nav .inner{display:flex;align-items:center;gap:18px;max-width:1080px;margin:0 auto;padding:12px 22px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:16px;color:var(--ink)}
.brand .mk{width:28px;height:28px;border-radius:9px;background:linear-gradient(135deg,var(--brand),var(--brand2))}
.brand small{display:block;font-size:10.5px;font-weight:600;color:var(--faint);letter-spacing:.04em}
.nav .links{margin-left:auto;display:flex;gap:6px;align-items:center}
.nav .links a{padding:7px 13px;border-radius:9px;color:var(--muted);font-weight:600;font-size:14px}
.nav .links a:hover{background:#eef0fb;color:var(--ink)}
.nav .links a.active{color:var(--brand);background:#eef0fb}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:8px;font-weight:700;font-size:14.5px;border-radius:11px;padding:11px 18px;border:1px solid var(--line);background:#fff;color:var(--ink);cursor:pointer;transition:.12s}
.btn:hover{border-color:#c7cbf6}
.btn-primary{background:linear-gradient(135deg,var(--brand),var(--brand2));color:#fff;border:0;box-shadow:0 6px 18px rgba(79,70,229,.25)}
.btn-primary:hover{filter:brightness(1.05)}
.btn-ghost{background:transparent}

/* hero */
.hero{padding:64px 0 30px}
.hero .eyebrow{font-size:12.5px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--brand)}
.hero h1{font-size:42px;line-height:1.08;letter-spacing:-.02em;margin:12px 0 14px;max-width:18ch}
.hero p.lead{font-size:18px;color:var(--muted);max-width:60ch;margin:0 0 24px}
.hero .cta{display:flex;gap:12px;flex-wrap:wrap}

/* sections */
.section{padding:34px 0}
.section h2{font-size:13px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin:0 0 16px}
.grid{display:grid;gap:16px}
.grid.cards{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
.card h3{margin:0 0 6px;font-size:16px}
.card p{margin:0;font-size:14px;color:var(--muted)}
.card .ic{width:34px;height:34px;border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:18px;background:#eef0fb;margin-bottom:12px}

/* tier comparison */
.tiers{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.tier{border:1px solid var(--line);border-radius:var(--radius);padding:20px;background:var(--card);box-shadow:var(--shadow)}
.tier .pill{display:inline-block;font-size:11px;font-weight:800;letter-spacing:.04em;border-radius:999px;padding:3px 11px;margin-bottom:10px}
.tier.t1 .pill{background:#e7f3ec;color:var(--ok)}
.tier.t2 .pill{background:#eef0ff;color:var(--brand)}
.tier h3{margin:2px 0 8px;font-size:19px}
.tier ul{margin:8px 0 0;padding-left:18px;color:var(--muted);font-size:14px}
.tier li{margin:4px 0}
.tier .note{margin-top:12px;font-size:12.5px;color:var(--faint)}

/* generic page header */
.pagehead{padding:30px 0 6px}
.pagehead h1{font-size:26px;margin:0 0 4px}
.pagehead p{color:var(--muted);margin:0;font-size:15px}

/* footer */
footer.site{margin-top:40px;border-top:1px solid var(--line);background:#fff}
footer.site .inner{max-width:1080px;margin:0 auto;padding:22px;color:var(--faint);font-size:12.5px;display:flex;gap:14px;flex-wrap:wrap;justify-content:space-between}

/* demo layout */
.demo-wrap{display:grid;grid-template-columns:300px 1fr;gap:0;height:calc(100vh - 58px)}
.demo-side{border-right:1px solid var(--line);background:#fff;overflow:auto;padding:14px}
.demo-side h2{font-size:11px;text-transform:uppercase;letter-spacing:.07em;color:var(--muted);margin:6px 4px 10px}
.pf{display:block;width:100%;text-align:left;border:1px solid var(--line);background:#fff;border-radius:12px;padding:11px 12px;margin-bottom:10px;cursor:pointer;transition:.12s}
.pf:hover{border-color:#c7cdfb}
.pf.on{border-color:var(--brand);box-shadow:0 0 0 2px rgba(79,70,229,.15)}
.pf .nm{font-size:13.5px;font-weight:700;line-height:1.3}
.pf .ctx{font-size:11.5px;color:var(--muted);margin-top:2px}
.pf .row{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px}
.tagc{font-size:10.5px;font-weight:700;border-radius:999px;padding:2px 8px;background:#eef0ff;color:var(--brand)}
.st{font-size:10.5px;border-radius:999px;padding:2px 8px;background:#f0f2f7;color:var(--muted)}
.st.crit{background:#fce9ed;color:var(--crit)}
.demo-main{display:flex;flex-direction:column;min-width:0}
.tabs{display:flex;gap:8px;padding:12px 16px;border-bottom:1px solid var(--line);background:#fff;flex-wrap:wrap;align-items:center}
.tab{font-size:13px;font-weight:600;border:1px solid var(--line);background:#fff;border-radius:999px;padding:6px 14px;cursor:pointer}
.tab.on{background:var(--ink);color:#fff;border-color:var(--ink)}
.bar{font-size:12.5px;color:var(--muted);padding:8px 16px;border-bottom:1px solid var(--line);background:#fbfcfe}
.frame{flex:1;min-height:0;background:#f6f7fa}
.frame iframe{width:100%;height:100%;border:0;background:#fff}
.openbtn{margin-left:auto;font-size:12.5px;color:var(--brand);font-weight:600}

/* studio layout */
.studio-wrap{display:grid;grid-template-columns:430px 1fr;gap:0;height:calc(100vh - 58px)}
.editor{border-right:1px solid var(--line);background:#fff;display:flex;flex-direction:column;min-height:0}
.editor .head{padding:14px 16px 10px;border-bottom:1px solid var(--line)}
.editor .head h2{margin:0 0 2px;font-size:16px}
.editor .head p{margin:0;font-size:12.5px;color:var(--muted)}
.editor .controls{display:flex;gap:8px;flex-wrap:wrap;padding:12px 16px;border-bottom:1px solid var(--line);align-items:center}
.editor select{font:inherit;font-size:13px;padding:7px 10px;border:1px solid var(--line);border-radius:9px;background:#fff}
.editor textarea{flex:1;min-height:0;width:100%;border:0;resize:none;padding:14px 16px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12.5px;line-height:1.5;color:#1c2433;outline:none}
.editor .foot{display:flex;gap:10px;align-items:center;padding:12px 16px;border-top:1px solid var(--line)}
.msg{font-size:12.5px}
.msg.err{color:var(--crit)} .msg.ok{color:var(--ok)}
.preview{display:flex;flex-direction:column;min-width:0}
.preview .pbar{display:flex;align-items:center;gap:10px;padding:10px 16px;border-bottom:1px solid var(--line);background:#fff;font-size:12.5px;color:var(--muted);flex-wrap:wrap}
.preview .frame{flex:1}
.empty-preview{margin:auto;text-align:center;color:var(--faint);padding:40px;max-width:40ch}

@media(max-width:820px){
  .tiers{grid-template-columns:1fr}
  .demo-wrap,.studio-wrap{grid-template-columns:1fr;height:auto}
  .demo-side{max-height:none}
  .frame,.preview .frame{height:78vh}
  .editor textarea{height:42vh}
  .hero h1{font-size:32px}
}