line-height for headers

Hi @pothibo,
I was reading your blog on a small resolution and was kind of annoyed by the line height on headers.

![screen shot 2014-06-13 at 13 02 18](https://cloud.githubusercontent.com/assets/10755/3269327/5c42e652-f2eb-11e3-9cd4-0af68a52e401.png)

![screen shot 2014-06-13 at 13 03 41](https://cloud.githubusercontent.com/assets/10755/3269325/582e5e34-f2eb-11e3-8576-5c5ed990e696.png)

Cheers