:root{
  --bg:#f6f7fb; --card:#fff; --accent:#2563eb; --muted:#6b7280;
  --radius:10px; font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,"Helvetica Neue",Arial;
}
*{box-sizing:border-box}
body{margin:0;padding:28px;background:var(--bg);color:#111}
header{margin-bottom:18px}
h1{color:var(--accent);margin:0 0 6px}
p{color:var(--muted);margin:0}
main{display:grid;gap:12px;grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.card{background:var(--card);padding:18px;border-radius:var(--radius);box-shadow:0 6px 18px rgba(16,24,40,0.06)}
footer{margin-top:18px;color:var(--muted)}
code{background:#f3f4f6;padding:2px 6px;border-radius:6px}