multiple elements with different modes and themes

The example shows multiple elements highlighted with different modes and
themes all in the same page. The pre element isn't ideal.

The example shows how to transfer the computed width and height of the
element into its inline style so that it won't dramatically change shape
and disrupt the page once it's had highlighting applied. It would
probably be better to replace the elements entirely and apply sizing
styles to the replacement elements but that isn't always an option.