Issues with H1 CSS

Hi guys,

I simply can’t seem to get my H1 to work properly.

Check out this link, you’ll notice the word Australia up the top. When it first loads up, it displays the way I want it to as per the H1 tag in my stylesheet, but after a second or two it changes to a thin & barely readable word.

This is what I have in my style.css for H1:

.main_post h1 { font-family: Century Gothic, Helvetica, Arial; color: #c9c8c8; font-size: 36px; font-weight: normal; margin: -10px 0 10px 0; padding: 0;}

Any idea why it reverts back to a thin weight after a second, and how do I get my desired H1 to stay as it is?

Thank you,

Dan