Assign css id to a selector into div container

[raygold]

I have the following html code:

<div class="firstclass" id="firstid">    <div class="a-block-content">   <h2 class="text-align-center"><a href="#">Some text</a></h2>  </div> </div>

How can I edit only h2 element using #firstid? Is it possible edit the second div container style

  <div class="a-block-content">   <h2 class="text-align-center"><a href="#">Some text</a></h2>  </div>

using #firstid? P.S. I can't edit html code, only css style.

[thescientist]

you could use javascript/jquery if you need to manipulate the DOM and are abstracted away from the actual markup itself.

[raygold]

What about css selectors? Can I use them to solve my issue?

[dsonesuk]

Using id ref

#firstid h2 a{color: red;}

would give it higher precedence over

.a-block-content h2 a {color: lime;}