Resize page height in Twenty Twelve

That big gap is coming from the following settings on about line 972 of your theme’s style.css:

.site-content article {
  margin-bottom: 5.14286rem;
  padding-bottom: 1.71429rem;
}

To remove it, you can add custom CSS that reduces or removes that extra space. For example, you could add this:

.site-content article {
  margin-bottom: none;
}

If you want to reduce it even more, you could reduce the amount of padding-bottom, too.

If you’re going to make these kinds of modifications to a theme, you really should be working with a child theme so your changes aren’t overwritten when there is a theme update.

Thanks a lot, linux4me2!

It worked when I put the value “0” instead of “none;” in the code you wrote

.site-content article {
  margin-bottom: 0
}

EDIT: I just installed the plug-in “Child Theme Configurator” and copied my current theme with all my changes into this. This will work as a back-up, right?

Again, THANKS A LOT!

Whoops! Sorry about that. Yes, zero is the default for margin-bottom, not “none”.

Make sure to end all CSS declarations with a semi-colon like this:

.site-content article {
  margin-bottom: 0;
}

I haven’t used the Child Theme Configurator, so I can’t answer that. I prefer to use as few plugins as possible–the less third-party code, the better–so building a child theme as described in the Codex article I linked to above is the way to go, I think. It’s not as complicated as it sounds.

For Twenty Twelve, in addition to the style.css with your custom CSS, you’ll need a functions.php in your child theme folder with the following in it to enqueue the parent Twenty Twelve theme:

<?php
  add_action('wp_enqueue_scripts', 'enqueue_parent_theme_style');
  function enqueue_parent_theme_style() {
    wp_enqueue_style('parent-style', get_template_directory_uri() . '/style.css');
  }
?>