:root{--bg:#0b0c0f;--fg:#e6e7ea;--muted:#a6adbb;--card:#14161a;--border:#2a2e36;--brand:#6aa6ff}
@media (prefers-color-scheme: light){:root{--bg:#fff;--fg:#111418;--muted:#586174;--card:#f7f8fa;--border:#e5e7eb;--brand:#2563eb}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--fg);font:14px/1.5 system-ui,Segoe UI,Roboto,Helvetica,Arial}
.header{padding:24px 16px;max-width:900px;margin:0 auto}
.lead{color:var(--muted)}
.container{max-width:900px;margin:0 auto;padding:0 16px 48px}
.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:12px;margin:12px 0}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:10px}
.row{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:8px}
label{display:flex;flex-direction:column;gap:4px;color:var(--muted)}
input,select{padding:8px 10px;border:1px solid var(--border);border-radius:8px;background:transparent;color:var(--fg)}
.btn{padding:8px 12px;border:1px solid var(--border);border-radius:8px;background:transparent;color:var(--fg);cursor:pointer}
.btn.primary{background:var(--brand);border-color:var(--brand);color:#fff}
.result{margin-top:8px;font-weight:600}