:root{
  --sans: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  --serif: ui-serif, Georgia, 'Iowan Old Style', 'Times New Roman', Times, serif;
  --ink:#0f172a; --muted:#475569; --accent:#0ea5e9; --border:#e5e7eb; --bg:#ffffff;
  --shadow:0 14px 44px rgba(0,0,0,.08);
  --col: 640px;
}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:18px/1.65 var(--sans)}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:1200px;margin:0 auto;padding:28px 20px 64px}
header.site{display:flex;align-items:center;justify-content:space-between;margin-bottom:12px}
.brand{font-family:var(--serif);font-weight:800;font-size:clamp(22px,3vw,28px);letter-spacing:.2px}
nav a{margin-left:18px;color:var(--muted)}
.hero{display:grid;grid-template-columns: minmax(320px, var(--col)) 1fr; gap:28px; align-items:center; margin-top:8px}
h1{font-family:var(--serif);font-weight:800;font-size:clamp(36px,5vw,56px); line-height:1.05; margin:10px 0 12px; max-width:20ch}
.lead{color:var(--muted);font-size:clamp(18px,2.2vw,22px);max-width:var(--col);margin:0 0 14px}
.hero p{max-width:var(--col)}
.hero img{width:100%;height:auto;border-radius:16px;box-shadow:var(--shadow)}
.section{margin-top:28px}
.card{border:1px solid var(--border);border-radius:18px;padding:20px;box-shadow:var(--shadow);max-width:var(--col)}
.card p{margin:0 0 12px}
.card h3{font-family:var(--serif);font-weight:800;margin:0 0 10px;font-size:24px}
.eth{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:10px}
.code{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,'Liberation Mono','Courier New',monospace;background:#f8fafc;border:1px solid var(--border);padding:10px 12px;border-radius:12px}
.btn{display:inline-flex;align-items:center;gap:8px;border:2px solid var(--border);background:#fff;color:#111;padding:10px 14px;border-radius:12px;font-weight:700;cursor:pointer}
.btn:hover{box-shadow:0 1px 0 rgba(0,0,0,.06)}
footer{margin-top:42px;color:#64748b;font-size:14px;max-width:var(--col)}
@media (max-width:980px){
  .container{padding-top:20px}
  .hero{grid-template-columns: 1fr; gap:16px}
  .card, footer{max-width:680px}
}