CSS3 - Pseudo classes - UI element

  button:enabled {
      border: 1pt solid blue;
  }
  

  <button>An enabled button</button>
  

  button:disabled {
      border: 1pt solid red;
  }
  

  <button disabled>A disabled button</button>
  

  input:checked {
      background-color: orange;
  }
  

  <div>
      <input type="radio" name="genderSelect" id="male" value="m"> <label for="male">Male</label>
      <input type="radio" name="genderSelect" id="female" value="f"> <label for="female">Female</label>
  </div>
  <input type="checkbox" id="over18"><label for="over18">Over 18?</label>