How do I change CSS for before or after of li when one of li is selected?

[shingoku]

\[code\]<li><span class="item-label">1</span><li><li><span class="item-label">2</span><li><li class="selected"><span class="item-label">3</span><li><li><span class="item-label">4</span><li><li><span class="item-label">5</span><li>\[/code\]Hi everyoneI want to ask how I can change CSS for before or after of li when one of li is selected. For example, If I select 3, I need to change the CSS for 2 and 4. Thanks your answer.