I discovered a great feature in the web developer's toolbar
(
http://chrispederick.com/work/webdeveloper/ )
By pressing Ctrl+Shift+E I opened an online CSS editor (in the sidebar) which is great for aligning things as well as learning CSS on a live page (you can change a CSS file for a page just visited and cached). And it displays embedded CSS (in the style attribute of elements) so you can movethem to an external file by Ctrl+C Ctrl+V.
Ofcourse there's more to the toolbar than that, but I was looking for an aligning tool like the CSS editor.