body { font-family: Arial, sans-serif; background:#0f172a; color:#e2e8f0; margin:0; }
.container { max-width:800px; margin:48px auto; padding:24px; background:#1e293b; border-radius:10px; }
input, button { display:block; width:100%; padding:10px; margin:10px 0; border-radius:6px; border:1px solid #334155; }
button { background:#22c55e; color:#0f172a; font-weight:700; cursor:pointer; }
.error { color:#f87171; }
pre { white-space: pre-wrap; }