Large image for homepage

I am testing Hemingway currently to see, if it fits my needs. I have to say, that I am pretty excited. There is just one thing, that bothers me. It is the size of the header image. Especially for the homepage.

• Is it possible to increase the size of the header image?
• Is it possible to do it for the homepage only?

Is there a special css code in the style.php, that defines/limits the size of the header image? Sorry, I could not find it.

I certainly would appreciate a little help. ??

Have a great day,
Axel