body {
  font-family: sans-serif;
  background: #f5f5f5;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
}

#app {
  width: 100%;
  max-width: 700px;
  padding: 20px;
}

#messages {
  background: white;
  padding: 15px;
  height: 60vh;
  overflow-y: auto;
  border-radius: 8px;
  margin-bottom: 15px;
  border: 1px solid #ddd;
}

.message {
  margin-bottom: 12px;
  line-height: 1.4;
}

.user {
  font-weight: bold;
  color: #0077cc;
}

.assistant {
  color: #333;
}

#input-area {
  display: flex;
  gap: 10px;
}

#user-input {
  flex: 1;
  padding: 10px;
  font-size: 16px;
}

#send-btn {
  padding: 10px 20px;
  font-size: 16px;
}

.hidden {
  display: none;
}