:root{--bg:#f9fafb;--fg:#111827;--accent:#b91c1c;--accent-soft:#fee2e2;--border-soft:#e5e7eb;--font-sans:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}*,:before,:after{box-sizing:border-box}body{font-family:var(--font-sans);background:var(--bg);color:var(--fg);margin:0}main{max-width:960px;margin:0 auto;padding:2rem 1.5rem 4rem}h1,h2,h3{font-weight:600}nav{border-bottom:1px solid var(--border-soft);background:#fff}nav .nav-inner{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:1rem;max-width:960px;margin:0 auto;padding:.75rem 1.5rem;display:flex}nav a{color:#374151;font-size:.95rem;text-decoration:none}nav a:hover{color:var(--accent)}.nav-links{flex-wrap:wrap;gap:.75rem;display:flex}.breadcrumb{color:#6b7280;margin-bottom:1rem;font-size:.8rem}.card{border:1px solid var(--border-soft);background:#fff;border-radius:.75rem;margin-bottom:1rem;padding:1rem 1.25rem}.card h2{color:var(--accent);margin-top:0}.grid{gap:1rem;display:grid}@media (min-width:768px){.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}}ul.topic-list{margin:.25rem 0 .75rem}ul.topic-list li{margin-left:1.25rem}table{border-collapse:collapse;width:100%;margin-top:.75rem;font-size:.95rem}th,td{border:1px solid var(--border-soft);text-align:left;padding:.4rem .6rem}th{background:#f3f4f6;font-weight:600}