Increase logo

Hi,

I’m wondering if the logo on this theme can be increased?
I’ve tried using this but it appears as a blurred image no matter how large the original image is or what I do when trying to manually enlarge it.
a.site-logo-link img {
width: 128px;
height: 128px;
}

.site-title { padding-top: 20px; }
Any help would be appreciated.
my site is http://www.europaunited.eu