body {
  font-family: sans-serif;
  max-width: 600px;
  margin: 20px auto;
}

h1 {
  text-align: center;
}

#messages {
  list-style: none;
  padding: 0;
  border: 1px solid #ccc;
  min-height: 100px;
  margin-bottom: 20px;
}

#messages li {
  padding: 8px 10px;
  border-bottom: 1px solid #eee;
}

#messages li:last-child {
  border-bottom: none;
}

form {
  display: flex;
  gap: 8px;
}

form input[type="text"] {
  flex: 1;
  padding: 6px 8px;
}

button {
  padding: 6px 12px;
  cursor: pointer;
}