How to justify text in WordPress

I’ve always had a thing for justified text, but never went through the (really small!) trouble of fixing the ugly text alignment in WordPress. Justifying your posts, though, is quite trivial. I’ll focus here on how it’s done on the Carrington theme because that’s what I use, but the general principle is:

1) Post contents are contained within a div with classes entry-content and full-content. I suspect that the first is always used, while the latter is only used when the post is displayed in full.
2) Find your theme’s CSS files, and somewhere add code to justify the text (text-align:justify) in the entry-content class

So, to apply this to Carrington:

1) In your admin panel, go to Appearance → Editor
2) Open up css.php (its full name is css/css.php, but for some reason the folder doesn’t appear in the list)
3) Just before ?>, add echo ".entry-content{text-align:justify}\n\n";
4) Click “Update file” to save it
5) Go back to your blog’s homepage and refresh (maybe CTRL+F5 to flush the CSS in cache)

For those curious and not knowing much about PHP, css.php merges several CSS files into a single one. The line we added in it simply adds CSS .entry-content{text-align:justify} at the end of the merger. That’s not very clean, but it’s good enough considering that Carrington is barely updated nowadays (if css.php gets overwritten by an update, you’ll need to reapply this modification).