:root{--bg:#f7f7f8;--card:#fff;--text:#1f2937;--muted:#6b7280;--line:#e5e7eb;--accent:#111827}
*{box-sizing:border-box}
body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:var(--bg);color:var(--text);line-height:1.65}
main{max-width:860px;margin:48px auto;padding:0 20px 56px}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:34px;box-shadow:0 8px 30px rgba(0,0,0,.04)}
h1{font-size:2rem;line-height:1.2;margin:0 0 8px} h2{font-size:1.15rem;margin-top:30px}
p,li{font-size:1rem}.muted{color:var(--muted)} nav{margin-bottom:22px}
nav a{color:var(--accent);margin-right:18px;text-decoration:none;font-weight:600}
footer{margin-top:36px;padding-top:22px;border-top:1px solid var(--line);color:var(--muted);font-size:.92rem}
@media(max-width:640px){main{margin:20px auto;padding:0 12px 32px}.card{padding:22px}h1{font-size:1.6rem}}