:root{font-family:system-ui,-apple-system,"Segoe UI",sans-serif;color:#1f2937;background:#f8fafc}body{margin:0}main{max-width:960px;margin:auto;padding:48px 24px}header{display:flex;gap:16px;align-items:center;margin-bottom:36px}header>b{display:grid;place-items:center;width:48px;height:48px;border-radius:12px;background:#111827;color:#fff;font-size:24px}h1{margin:0 0 6px}header p,footer{color:#64748b}section{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px}article{background:#fff;border:1px solid #e2e8f0;border-radius:14px;padding:22px}footer{margin-top:36px}@media(prefers-color-scheme:dark){:root{background:#111827;color:#e5e7eb}article{background:#172033;border-color:#334155}}