body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 1rem;
    background: #fafafa;
  }
  header {
    background: #ddd;
    padding: 1rem;
  }
  nav a {
    margin-right: 1rem;
    text-decoration: none;
    color: #333;
  }
  main {
    max-width: 400px;
    margin: 2rem auto;
    background: #fff;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  }
  section {
    margin-bottom: 2rem;
  }
  h2 {
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
  }
  form {
    display: flex;
    flex-direction: column;
  }
  label {
    margin-bottom: 0.75rem;
  }
  input {
    padding: 0.5rem;
    font-size: 1rem;
  }
  button {
    padding: 0.6rem;
    font-size: 1rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
  }
  #loginResponse,
  #signupResponse {
    margin-top: 1rem;
    font-weight: bold;
  }
  hr {
    border: none;
    border-top: 1px solid #eee;
    margin: 2rem 0;
  }