Fix active page margin for pagination

Love your Blog and Code Bright, but this has been driving me crazy for a few months --silly, right?
Your active page within your blog isn't marginally correct in comparison to the other offset pages. I just grabbed an em from your CSS and added a quick styling. Doing so, gave some desirable results.

before
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![before](https://cloud.githubusercontent.com/assets/3615935/2747851/f4393b10-c78e-11e3-835e-eb873b60008a.jpg)
![screenshot3](https://cloud.githubusercontent.com/assets/3615935/2747864/b7e9a486-c790-11e3-9284-1158489ad74f.jpg)


after
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![screenshot1](https://cloud.githubusercontent.com/assets/3615935/2747857/e8db392a-c78f-11e3-9904-92c0586087dc.png)
![screenshot2](https://cloud.githubusercontent.com/assets/3615935/2747860/35f04192-c790-11e3-8dc1-5e9eb3ac8a5c.jpg)