<form>
  <h2>Login</h2>

  <div>
    <label for="email">Email</label>
    <input type="email" id="email" name="email" required />
  </div>

  <div>
    <label for="password">Password</label>
    <input type="password" id="password" name="password" required />
  </div>

  <div>
    <button type="submit">Login</button>
  </div>
</form>
  
  #email:invalid {
    border: 1px solid red;
  }

  #password:invalid {
    border: 1px solid red;
  }

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