body {
  font-family: system-ui, sans-serif;
  max-width: 600px;
  margin: 2rem auto;
  padding: 1rem;
  background: #f5f7fa;
}
.chat-box {
  border: 1px solid #ccc;
  padding: 1rem;
  background: #fff;
  height: 400px;
  overflow-y: auto;
  margin-bottom: 1rem;
  font-size: 14px;
}
.chat-box p {
  margin: 0.5rem 0;
}
.user { font-weight: bold; color: #333; }
.bot { color: #0066cc; }
.input-row {
  display: flex;
  gap: 0.5rem;
}
input {
  flex: 1;
  padding: 0.5rem;
  font-size: 16px;
}
button {
  padding: 0.5rem 1rem;
  font-size: 16px;
}