How can I place my header in the center of the header box?

[kittyrefuge]

I have been trying to find out the answer for the last (OMG) 5 hours...Now I'm hoping somebody can help me out from this situation.

The Base Style I'm using is Blanket.



#title span { display: none; }
#title {
position: center;
width: 500px;
height: 250px;
margin-left: auto;
margin-right: auto;
margin-bottom: 0px;
background-image: url("https://ic.pics.livejournal.com/kittyrefuge/12716922/407688/407688_original.jpg");
background-repeat: no-repeat;
}

But the result is :



And when I check it on my phone :

My header pic goes out of the frame...

Somebody, please?