are styled using the CSS <code>:hover</code> pseudo-class, and <code>focus</code> and <code>blur</code> event handlers:
            <ul>
              <li>To make it easier to perceive when the combobox receives focus, focus creates a 2 pixel focus ring around both the <code>input</code> and <code>button</code> elements with 2 pixels of space between the focus ring and the combobox.</li>
              <li>To make it easier to perceive that either the input or button can be clicked to open the listbox, hover