:root{--bg:#f6f7f9;--card:#fff;--text:#16181d;--muted:#5d6573;--border:#dfe3ea;--accent:#1f6feb}@media (prefers-color-scheme:dark){:root{--bg:#0f1115;--card:#181b22;--text:#eef0f4;--muted:#a3acba;--border:#2a2f3a;--accent:#6ea8ff}}*{box-sizing:border-box}html,body{background:var(--bg);color:var(--text);margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5}main{place-items:center;min-height:100dvh;padding:24px 16px;display:grid}.card{background:var(--card);border:1px solid var(--border);text-align:center;border-radius:14px;width:100%;max-width:440px;padding:32px 28px}.card h1{margin:0 0 12px;font-size:1.5rem}.card p{color:var(--muted);margin:0 0 12px}.reference{color:var(--muted);margin-top:20px;font-size:.85rem}.reference code{color:var(--text);letter-spacing:.04em;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}