html - Wrapping CSS pseudo-element -

is possible simulate div around b , c items , style without changing html?

i know there ::before , ::after pseudo-elements couldn't find "wrapping" element. maybe ::wrap(.b, .c).

<ul>     <li class="a">a</li>     <li class="b">b</li>     <li class="c">c</li>     <li class="d">d</li> </ul> 

a example isolating , putting single background image behind b , c.

wouldn't like,

li.c,li.b { border: 1px solid black; }