body { font-family: Segoe UI, sans-serif; margin: 0; display: flex;
       flex-direction: column; height: 100vh; }
#log { flex: 1; overflow-y: auto; padding: 8px; }
#log .you { text-align: right; color: #036; margin: 6px 0; }
#log .ai  { color: #111; margin: 6px 0; white-space: pre-wrap; }
#bar { display: flex; border-top: 1px solid #ccc; padding: 6px; }
#input { flex: 1; padding: 6px; }
#send { padding: 6px 12px; }