how to? if is_front = div class "front-content" else "content"
Instead of adding a new class (and a div) you can simply target and override the layout for the front page in your style sheet with:

.front .content {
  width: 70%;
}


It's possibly you need to be more specific though, so you don't target all .content on the page. I don't know how you theme code looks, but it should be something like .front #main .content.

This assumes that your theme uses the default body classes in html.tpl.php for Drupal 7

&lt;body class="&lt;?php print $classes; ?&gt;" &lt;?php print $attributes;?&gt;&gt;


Or page.tpl.php for Drupal 6.

&lt;body class="&lt;?php print $body_classes; ?&gt;"&gt;


Cheers,