:root{font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color-scheme:light dark}body{margin:0;min-height:100vh;display:flex;align-items:center;justify-content:center;background:#0f172a;color:#f1f5f9}.card{max-width:420px;width:100%;padding:2rem;border-radius:12px;background:#1e293b;box-shadow:0 10px 30px #0000004d}h1{font-size:1.5rem;margin-bottom:.5rem}p.subtitle{color:#94a3b8;margin-top:0;margin-bottom:1.5rem}button{background:#6366f1;color:#fff;border:none;padding:.6rem 1.2rem;border-radius:8px;font-size:1rem;cursor:pointer}button:disabled{opacity:.6;cursor:not-allowed}pre{margin-top:1rem;padding:1rem;background:#0f172a;border-radius:8px;overflow-x:auto;font-size:.85rem;white-space:pre-wrap;word-break:break-word}