I installed the Neptune template and added some pages. For some reason the "Prev" and "Next" links were stuck over to the left side of the page. The repair is easy.
In your administrator back-end navigate to Extensions > Template Manager. Click into J51_Neptune and then into the "Edit CSS" in the upper right row of icons. Set the radio button for "template.css" and click "Edit" which will open the file for editing. Scroll down to the line reading: /* Pagination */. Add the following code at the end of that section.
table.pagenav {width: 100%;} /* At the suggestion of Ciaran */
I always add a comment so I know I entered it and / or from where I got the hint. That way in the future I know I can back out any statements made to the original file. It is more than likely that other CSS statements could be added to the class for further styling.
This may apply to other Joomla51 templates as well where you wish to style your previous and next links.