:root { font-family: system-ui, sans-serif; }
main { max-width: 720px; margin: 2rem auto; padding: 1rem; }
#chat { border: 1px solid #ddd; padding: 1rem; height: 60vh; overflow-y: auto; border-radius: 8px; }
.user { text-align: right; margin: .5rem 0; }
.assistant { text-align: left; margin: .5rem 0; }
form { display: flex; gap: .5rem; margin-top: .75rem; }
input { flex: 1; padding: .5rem; }
button { padding: .5rem .75rem; }