body {
  font-family: Arial;
  background: #f5f5f5;
}

.chat {
  max-width: 700px;
  margin: 50px auto;
  background: white;
  padding: 20px;
  border-radius: 15px;
}

#messages {
  height: 400px;
  overflow-y: auto;
  border: 1px solid #ddd;
  padding: 15px;
}

.input {
  display: flex;
  margin-top: 15px;
}

input {
  flex: 1;
  padding: 12px;
}

button {
  padding: 12px 20px;
}