:root{--fg:#0f172a;--muted:#475569;--bg:#f8fafc;--card:#ffffff;--brand:#2563eb;}
body{font:16px/1.55 system-ui,-apple-system,Segoe UI,Roboto,Inter,Arial,sans-serif;color:var(--fg);background:var(--bg);}
.nav{display:flex;align-items:center;justify-content:space-between;padding:14px 24px;background:#fff;border-bottom:1px solid #e5e7eb;position:sticky;top:0;z-index:10;}
.brand{font-weight:700;letter-spacing:.2px;}
.tabs{display:flex;gap:18px;}
.tabs a{text-decoration:none;color:var(--muted);padding:6px 10px;border-radius:8px;}
.tabs a:hover{background:#eef2ff;color:#1e293b;}
.backlink{display:inline-block;text-decoration:none;font-weight:600;padding:10px 12px;color:var(--fg);}
.backlink:hover{background:#eef2ff;border-radius:8px;}
.wrap{max-width:1100px;margin:0 auto;padding:24px;}