<!DOCTYPE html>
    /* when the element 
     has the cursor focus. */
    textarea:focus {
      background-color: yellow;

    /* when the element is enabled
     and ready to use (the normal state). */
    input:enabled  {
      color: green;

    /* when the element is disabled (has
     the disable attribute). */
    input:disabled  {
      color: gray;

    /* when the checkbox is checked. */
    input:checked {
      width: 50px;
      height: 50px;
    <textarea>Try edit this textare</textarea>
    <input type="text" value="normal input">
    <input type="text" value="disabled input" disabled>
    <input type="checkbox"> Try to check this.