Modification of Post's title.

I’ve tried almost anything for over a hour and half without any success.
Here’s my style.css code:
http://pastebin.com/Qed5GP4p (I’m using twenty fifteen theme)

I tried editing the .entry-title, tried deleting the headers section (to see if it will make any difference on my website), searching help in google, and more more.

here’s my website’s first post: (it’s in hebrew tho) http://bebetteryou.net/

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