body { font-family: sans-serif; max-width: 900px; margin: 2rem auto; padding: 0 1rem; }
form { display: flex; flex-direction: column; gap: 0.5rem; max-width: 500px; margin-bottom: 1.5rem; }
.error { color: #b00020; }
pre#run-log { background: #111; color: #0f0; padding: 1rem; max-height: 300px; overflow-y: auto; }