tinboard logo do not fit in header

Hi guys

I am trying to fit the entire header with my logo in my pinboard theme, 1164 x 752 pix. I use the following code to css
#site-title {
margin:0;
line-height:0;
float:left;
}

and unchecked the “Retina Header Image” box as suggested in the forum.
However, it is not working.
can anyone kindly help please!

my site is http://www.creativedesire.net