:root{--bg:#fafafa;--fg:#18181b;--muted:#52525b;--accent:#2563eb;--card:#fff;--border:#e4e4e7}@media (prefers-color-scheme:dark){:root{--bg:#0b0b0d;--fg:#f4f4f5;--muted:#a1a1aa;--accent:#60a5fa;--card:#17171a;--border:#27272a}}*{box-sizing:border-box}body{background:var(--bg);color:var(--fg);margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5}main{max-width:40rem;margin:0 auto;padding:4rem 1rem}.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:1.5rem}.muted{color:var(--muted)}.button{border:1px solid var(--border);background:var(--accent);color:#fff;font:inherit;cursor:pointer;border-radius:8px;padding:.6rem 1rem;text-decoration:none;display:inline-block}.button.secondary{color:var(--fg);background:0 0}.error{border-left:3px solid #dc2626;padding-left:.75rem}