There’s no need to modify files inside the Safari app bundle to to change the text alignment from justified to left-aligned. Just apply your custom stylesheet (or use mine) in the Safari Preferences > Advanced tab
http://jonpoh.com/downloads/safari_reader_left.css
Save the above CSS somewhere on your hard disk and select it in Safari’s Preferences.
Note: I found those selectors using the Webkit Web Inspector. It MAY conflict with styles on some websites. Please let me know if you notice any problems with it, or if you have any suggestions on improving it.
UPDATE: seems I should have done a bit more testing. My trick doesn’t work after all. Move along now, nothing to see here :)
