:root{--fg:#111;--muted:#5a5a5a;--link:#0366d6;--bg:#fff;--card:#fafafa}
*{box-sizing:border-box}body{margin:0;font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:var(--fg);background:var(--bg)}
.wrap{max-width:900px;margin:0 auto;padding:48px 20px}
nav{border-bottom:1px solid #eee;background:#fff;position:sticky;top:0}
nav .inner{max-width:900px;margin:0 auto;display:flex;gap:18px;align-items:center;padding:12px 20px}
nav a{color:var(--fg);text-decoration:none;padding:6px 8px;border-radius:6px}
nav a:hover{background:#f3f3f3}
h1{margin:0 0 8px 0}
.lead{color:var(--muted)}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
@media(max-width:760px){.grid{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid #eaeaea;border-radius:12px;padding:16px}
footer{margin-top:36px;color:var(--muted);font-size:.9rem}
ul{margin:8px 0 0 18px}
.btn{display:inline-block;padding:10px 14px;border:1px solid #e5e5e5;border-radius:10px;text-decoration:none}