Problems With Main Nav Height

Hello friends.

I’m trying to fix this problem with my nav bar height but I can’t. I uploaded two pics to explain what I want. I’m very glad if someone could help me. Thanks!

http://postimg.org/image/soyhkj7ij/ (my blog is like this, wrong)
http://postimg.org/image/fwadklvwr/ (I want like this)

If someone want to take a look, my blog is: http://bloganacastro.com

Thanks until now!